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Statistical Loads Data for Boeing 737-400 Aircraft in Commercial Operations

August 1998 Final Report

This document is available to the U.S. public through the National Technical Information Service (NTIS), Springfield, Virginia 22161.

U.S. Department of Transportation Federal Aviation Administration

NOTICE This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The United States Government assumes no liability for the contents or use thereof. The United States Government does not endorse products or manufacturers. Trade or manufacturer's names appear herein solely because they are considered essential to the objective of this report.

Technical Report Documentation Page 1. Report No.

2. Government Accession No.

3. Recipient's Catalog No.

DOT/FAA/AR-98/28 4. Title and Subtitle

5. Report Date

STATISTICAL LOADS DATA FOR BOEING 737-400 AIRCRAFT IN COMMERCIAL OPERATIONS 7. Author(s)

August 1998 6. Performing Organization Code

8. Performing Organization Report No.

John Rustenburg, Donal Skinn, Daniel O. Tipps

URD-TR-98-00032

9. Performing Organization Name and Address

10. Work Unit No. (TRAIS)

University of Dayton Research Institute Structural Integrity Division 300 College Park Dayton, OH 45469-0120

RPD-510-1998-00032 11. Contract or Grant No.

FAA Grant No. 96-G-020

12. Sponsoring Agency Name and Address

13. Type of Report and Period Covered

U.S. Department of Transportation Federal Aviation Administration Office of Aviation Research Washington, DC 20591

Final Report 14. Sponsoring Agency Code

AAR-431

15. Supplementary Notes

The Federal Aviation Administration William J. Hughes Technical Center COTR is Thomas DeFiore 16. Abstract

The University of Dayton is supporting Federal Aviation Administration (FAA) research on the structural integrity requirements for the US commercial transport airplane fleet. The primary objective of this research is to support the FAA Airborne Data Monitoring Systems Research Program by developing new and improved methods and criteria for processing and presenting large commercial transport airplane flight and ground loads usage data. The scope of activities performed involved (1) defining the service related factors which affect the operational life of commercial aircraft; (2) designing an efficient software system to reduce, store, and process large quantities of optical quick access recorder data; and (3) providing processed data in formats that will enable the FAA to reassess existing certification criteria. Equally important, these new data will also enable the FAA, the aircraft manufacturers, and the airlines to better understand and control those factors which influence the structural integrity of commercial transport aircraft. Presented herein are analyses and statistical summaries of data collected from 11,721 flights representing 19,105 flight hours of 17 typical B-737-400 aircraft during operational usage recorded by a single airline. The statistical data presented include the initial recorded data previously reported in FAA report DOT/FAA/AR-95/21. The data include statistical information on accelerations, speeds, altitudes, flight duration and distance, gross weights, speed brake/spoiler cycles, thrust reverser usage, and gust velocities encountered.

17. Key Words

18. Distribution Statement

Optical quick access recorder, Flight profiles, Gust loads, Accelerations, Statistical summaries 19. Security Classif. (of this report)

Unclassified Form DOT F1700.7

(8-72)

This document is available to the public through the National Technical Information Service (NTIS), Springfield, Virginia 22161.

20. Security Classif. (of this page)

Unclassified Reproduction of completed page authorized

21. No. of Pages

86

22. Price

N/A

PREFACE The Flight Systems Integrity Group of the Structural Integrity Division of the University of Dayton Research Institute (URDI) performed this work under Federal Aviation Administration (FAA) Grant No. 96-G-020 entitled “Aircraft Operational Usage for Service Life Management and Design Criteria Development.” The Program Manager for the FAA was Mr. Thomas DeFiore of the FAA William J. Hughes Technical Center at Atlantic City International Airport, New Jersey, and the Program Technical Advisor was Mr. Terence Barnes of the FAA Aircraft Certification Office. Mr. Daniel Tipps was the Principal Investigator for the University of Dayton and provided oversight direction for this effort. Mr. Donald Skinn developed the data reduction algorithms, established data reduction criteria, and performed the data reduction. Mr. John Rustenburg performed the data analysis, created the graphical presentations, and prepared the report. Ms. Andrea Snell compiled and formatted the report for publication.

iii/iv

TABLE OF CONTENTS

Page EXECUTIVE SUMMARY

xi

1.

INTRODUCTION

1

2.

AIRCRAFT DESCRIPTION

1

3.

AIRLINE DATA COLLECTION AND EDITING SYSTEMS

2

3.1 3.2

2

3

4.

Data Collection System Data Editing System

UNIVERSITY OF DAYTON RESEARCH INSTITUTE DATA PROCESSING

3

4.1 4.2 4.3

Data Reduction

Recorded Parameters

Computed Parameters

4 5 6

4.3.1 4.3.2 4.3.3 4.3.4 4.3.5

6 7 7 7 8

4.4

Data Reduction Criteria

4.4.1 4.4.2 4.4.3 4.4.4 4.4.5 4.4.6

5.

Atmospheric Density

Equivalent Airspeed

Dynamic Pressure (q)

Derived Gust Velocity (Ude)

Continuous Gust Intensity (Uσ)

9

Phases of Flight

Flight Distance

Sign Convention

Peak-Valley Selection

Separation of Maneuver and Gust Load Factors Flap Detents

9 11 11 12 13 15

DATA PRESENTATION

15

5.1

Aircraft Operational Usage Data

15

5.1.1 5.1.2 5.1.3 5.1.4

18 19 19 19

Weight Data

Altitude Data

Flight Distance Data

Autopilot Usage

v

5.2

5.3

5.4

5.5

Ground Loads Data

20

5.2.1 5.2.2 5.2.3 5.2.4 5.2.5 5.2.6

20 20 20 21 21 21

Lateral Load Factor Data

Longitudinal Load Factor Data

Vertical Load Factor Data

Ground Speed Data

Flare Data

Pitch/Rotation Data

Flight Loads Data

21

5.3.1 Gust Loads Data

5.3.2 Maneuver Loads Data

5.3.3 Combined Maneuver and Gust Loads Data

21 22 22

Miscellaneous Operational Data

23

5.4.1 5.4.2 5.4.3 5.4.4

24 24 24 25

Flap Usage Data

Speed Brake/Spoiler Usage Data

Thrust Reverser Data

Landing Gear Extension/Retraction Data

Propulsion System Data

25

6.

CONCLUSIONS

25

7.

REFERENCES

27

APPENDICES AData Presentation

BGreat Circle Distance Calculation

vi

LIST OF FIGURES

Figure 1 2 3 4 5 6a 6b

Page Boeing 737-400 Three-View Drawing Airline Recording and Editing System Description of Phases of Flight Sign Convention for Airplane Accelerations The Peak-Between-Means Classification Criteria Current Acceleration Value Passes Into Deadband Current Acceleration Value Passes Through Deadband

2 3 10 12 12 13 13

LIST OF TABLES Table 1 2 3 4 5 6 7 8 9

Page Boeing 737-400 Aircraft Characteristics Recorded Parameters Provided to UDRI Parameter Editing Values Recorded Parameters Used in Data Reduction Phase of Flight Starting Criteria Peak Classification Criteria Flap Detents (B-737-400) Statistical Data Formats FAR Requirements for Derived Discrete Gust Velocities

vii

1 4 5 6 10 14 15 16 23

LIST OF SYMBOLS AND ABBREVIATIONS A a

aircraft PSD gust response factor speed of sound (ft/sec)

c C CLα

wing mean geometric chord (ft) aircraft discrete gust response factor aircraft lift curve slope per radian

C Lmax CAS c.g.

maximum lift coefficient calibrated air speed center of gravity

EAS

equivalent airspeed

F(PSD)

continuous gust alleviation factor

g

gravity constant, 32.17 ft/sec2

Hp

pressure altitude, (ft)

Kg KCAS KEAS KIAS kts

discrete gust alleviation factor, 0.88 µ/(5.3 + µ)

knots calibrated air speed

knots equivalent air speed

knots indicated air speed

knots

L

turbulence scale length (ft)

n N nm nx ny nz N0

load factor (g)

number of occurrences for Uσ (PSD gust procedure)

nautical mile

longitudinal load factor (g)

lateral load factor (g)

normal load factor (g)

number of zero crossings per nautical mile (PSD gust procedure)

q

dynamic pressure (lbs/ft2)

S

wing area (ft2)

TAS

true airspeed

Ude Uσ

derived gust velocity (ft/sec) continuous turbulence gust intensity (ft/sec)

viii

LIST OF SYMBOLS AND ABBREVIATIONS (Cont’d) VB VC VD

design speed for maximum gust

design cruise speed

design dive speed

Ve VT

equivalent airspeed

true airspeed

W

gross weight (lbs)

Δm

incremental acceleration due to a turning maneuver

Δnz Δnz man

incremental normal load factor, nz - 1 incremental maneuver load factor

Δnz gust

incremental gust load factor

µ

airplane mass ratio,

µp

statistical mean of p (parameter on plots)

ρ ρ0

air density, slugs/ft3 (at altitude) standard sea level air density, 0.0023769 slugs/ft3

σp

standard deviation of p (parameter on plots)

ϕ

bank angle (degrees)

2(W / S ) ρ gcCLα

ix/x

EXECUTIVE SUMMARY The University of Dayton is supporting Federal Aviation Administration (FAA) research on the structural integrity requirements for the US commercial transport airplane fleet. The primary objective of this research is to support the FAA Airborne Data Monitoring Systems Research Program by developing new and improved methods and criteria for processing and presenting large commercial transport airplane flight and ground loads usage data. The scope of activities performed involved (1) defining the service related factors which affect the operational life of commercial aircraft; (2) designing an efficient software system to reduce, store, and process large quantities of optical quick access recorder data; and (3) providing processed data in formats that will enable the FAA to reassess existing certification criteria. Equally important, these new data will also enable the FAA, the aircraft manufacturers, and the airlines to better understand and control those factors which influence the structural integrity of commercial transport aircraft. Presented herein are analyses and statistical summaries of data collected from 11,721 flights representing 19,105 flight hours of 17 typical B-737-400 aircraft during operational usage recorded by a single airline. The statistical data presented includes the initial recorded data previously reported in FAA report DOT/FAA/AR-95/21. The data include statistical information on accelerations, speeds, altitudes, flight duration and distance, gross weights, speed brake/spoiler cycles, thrust reverser usage, and gust velocities encountered.

xi/xii

1. INTRODUCTION. The Federal Aviation Administration (FAA) has an ongoing Airborne Data Monitoring Systems Research Program to collect, process, and evaluate statistical flight loads data from transport aircraft used in normal commercial airline operations. The objectives of this program are (a) to acquire, evaluate, and utilize typical operational in-service data for comparison with the prior data used in the design and qualification testing of civil transport aircraft and (b) to provide a basis to improve the structural criteria and methods of design, evaluation, and substantiation of future airplanes. Since the inception of the FAA’s Airborne Data Monitoring Systems Research Program, the scope of the program has steadily increased to include data collection on additional aircraft, different aircraft models, and additional operators. The University of Dayton has supported the FAA’s efforts and has responsibility for the data analysis and processing tasks and report preparation. In consultation with airplane manufacturers and operators, the University has enhanced and improved the data processing capabilities to allow reducing, analyzing, and reporting additional aircraft usage and statistical loads data from the digital flight loads recorders into a form that will fulfill the requests of the aircraft manufacturers, the airlines, and the FAA. The report presents data obtained from 17 airplanes over 11,721 flights and 19,105 hours of airline operations for the B-737-400 aircraft of a single operator. 2. AIRCRAFT DESCRIPTION. Table 1 presents certain operational characteristics of the 17 Boeing 737-400 aircraft which were equipped with optical quick access recorders. Figure 1 shows front, top, and side views of the aircraft and identifies its major physical dimensions. TABLE 1. BOEING 737-400 AIRCRAFT CHARACTERISTICS Maximum Taxi Weight Maximum Takeoff Weight Maximum Landing Weight Zero-Fuel Weight Fuel Capacity 2 CFM56-3 Engines Wing Span Wing Reference Area Wing MAC Wing Sweep Length Height Tread Wheel Base

143,000 lb 142,500 lb 121,000 lb 113,000 lb 5311 U.S. gallons @ 22,000 lbs static thrust each 94 ft 9 in 980 ft2 11 ft 2.46 in 25 degrees 119 ft 7 in 36 ft 6 in 17 ft 2 in 46 ft 10 in

1

FIGURE 1. BOEING 737-400 THREE-VIEW DRAWING 3. AIRLINE DATA COLLECTION AND EDITING SYSTEMS. The airline data collection and editing system consists of two major components: (1) the data collection system installed on board the aircraft and (2) the ground data editing station. A schematic overview of the system is given in figure 2. The requirements for the data acquisition and processing are defined in reference 1. The collection and editing systems are discussed below. 3.1 DATA COLLECTION SYSTEM. The on-board data collection system consists of a Digital Flight Data Acquisition Unit (DFDAU), a Digital Flight Data Recorder (DFDR), and an Optical Quick Access Recorder (OQAR). The DFDAU collects sensor signals and sends parallel data signals to both the DFDR and the OQAR. The OQAR is programmed to start recording once certain data signals are detected. The OQAR is equipped with an optical disk which can store up to 200 hours of flight data, whereas the DFDR uses a 25-hour looptape. The optical disk is periodically removed from the OQAR and forwarded to the ground processing station. 2

FIGURE 2. AIRLINE RECORDING AND EDITING SYSTEM 3.2 DATA EDITING SYSTEM. The airline ground data editing station consists of a Pentium computer, a magneto-optical (MO) disk drive, and flight data editing software. The software performs a number of functions during the process of transferring the raw flight data into DOS file format onto the hard disk. The most important of these functions include a data integrity check and removal of flight sensitive information. Data considered sensitive are those which can be used to readily identify a specific flight. The desensitized data are forwarded to the University of Dayton Research Institute (UDRI) for flight loads processing and analysis. Table 2 presents the recorded data parameters provided by the airline to UDRI. 4. UNIVERSITY OF DAYTON RESEARCH INSTITUTE DATA PROCESSING. The data parameters of table 2 are provided by the airline to UDRI for each recorded flight. The data are provided on magneto-optical disks containing binary files for multiple flights for different airplanes. These data are processed by UDRI to extract the parameters required for statistical flight loads presentation. This section describes the reduction of the data and the derivation of required parameters.

3

TABLE 2. RECORDED PARAMETERS PROVIDED TO UDRI

Parameter Normal Acceleration Lateral Acceleration Longitudinal Acceleration Aileron Position Elevator Position Rudder Position Pilot Trim Position Flap Handle Position Speed Brake Position N1 Engine - Left N1 Engine - Right Throttle #1 Position Throttle #2 Position Thrust Reverser Position Autopilot Status (on or off) Squat Switch (main gear) Gear Position Calibrated Airspeed Ground Speed Mach Number Pressure Altitude Gross Weight Bank Angle Pitch Angle Magnetic Heading Total Air Temperature Radio Altitude

Sample Rate 8 per second 4 per second 4 per second 1 per second 1 per second 2 per second 1 per second 1 per second 1 per second 1 per second 1 per second 1 per second 1 per second Discrete Discrete Discrete Discrete 1 per second 1 per second 1 per 4 seconds 1 per second 1 per 64 seconds 2 per second 4 per second 1 per second 1 per second 1 per second

4.1 DATA REDUCTION. Each file provided by the airline contains multiple flights for each airplane. These files are first separated into individual flight files and subsequently into individual time history files for each flight. The time history files are compressed and stored on the same 230 MB magneto-optical disks for later recall by the flight loads processing software. Data editing and verification are performed on the data as the time histories are being prepared. Messages alert the user that obviously erroneous data have been removed and that questionable data have been retained but need to be manually reviewed prior to their acceptance. Table 3 lists the limits against which the data are compared.

4

TABLE 3. PARAMETER EDITING VALUES

Item 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

Gross Weight Pressure Altitude (Hp) Calibrated Airspeed Normal Acceleration Lateral Acceleration Longitudinal Acceleration Flap Handle Position Elevator Position Aileron Position Rudder Position Trim Position Speed Brake Handle Position Throttles 1 and 2 Thrust Reverser Position Autopilot Status Squat Switch (main gear) Landing Gear Position

18. 19. 20. 21.

Pitch Attitude Bank Attitude Mach Number Ground Speed

Condition at start up at all times at all times during flight operations at start up and shut down in flight at all times at all times at all times at all times at all times at all times at all times at all times at all times stowed at start up and shutdown off or on closed at start up and shutdown down at start up and shutdown up within 10 seconds after takeoff down within 10 minutes before landing at all times at all times at all times at all times

Min

Max

75,000 lbs -2,000 ft 45 kts 0g ±0.5 g ±1.0 g 0° ±25° ±25° ±50° 0° 0°

150,500 lbs 45,000 ft 420 kts +4 g ±0.5 g ±1.0 g 45° ±25° ±25° ±50° 20° 60°

-5° 0 0 0 0

75° 1 1 1 1

-20° ±60° 0 0 kts

+30° ±60° 1 800 kts

Important characteristics about each set of flights received from the airline are recorded in a relational database. Airline identifier, aircraft tail number, and disk identifier of the disk received from the airline are in the data. Each flight is assigned a unique flight sequence number. The flight sequence number assigned to the first flight of the set and the number of flights in the set are also entered. Also recorded is the disk identifier of the MO disk, which contains the compressed time history files of all flights in the set. 4.2 RECORDED PARAMETERS. Not all parameters listed in table 2 are used for statistical analysis and data presentation. Table 4 lists the parameters used in the data reduction and for which time history files are created and compressed on the magneto-optical disk. These parameters are used by the summarization software for statistical analysis and data presentation.

5

TABLE 4. RECORDED PARAMETERS USED IN DATA REDUCTION

Flight Parameter Gross Weight Pressure Altitude Calibrated Airspeed Normal Acceleration (nz) Lateral Acceleration (ny) Longitudinal Acceleration (nx) Flap Handle Position Speed Brake Handle Position Thrust Reverser Position Autopilot Status (on or off) Squat Switch (main gear) Landing Gear Position Pitch Angle Bank Angle Mach Number Ground Speed Magnetic Heading N1 Engine - Left

Sample Rate 1 per 64 seconds 1 per second 1 per second 8 per second 4 per second 4 per second 1 per second 1 per second Discrete Discrete Discrete Discrete 4 per second 2 per second 1 per 4 seconds 1 per second 1 per second 1 per second

4.3 COMPUTED PARAMETERS. Derived gust velocity Ude and continuous gust intensity Uσ are important statistical load parameters which are derived from measured normal accelerations. This derivation of gust velocity Ude and continuous gust intensity Uσ from measured normal accelerations requires knowledge of atmospheric density, equivalent airspeed, and dynamic pressure. These values are calculated using equations that express the rate of change of density as a function of altitude based on the International Standard Atmosphere. 4.3.1 Atmospheric Density. For altitudes below 36,089 feet, the density ρ is expressed as a function of altitude by ρ = ρ o (1− 6 .876 × 10 −6 × Hp ) 4.256

(1)

where ρ0 is air density at sea level (0.0023769 slugs/ft3) and Hp is pressure altitude (ft). Pressure altitude is a recorded parameter.

6

4.3.2 Equivalent Airspeed. Equivalent air speed (Ve) is a function of true air speed (VT) and the square root of the ratio of air density at altitude (ρ) to air density at sea level (ρ0) Ve = VT

ρ ρ0

(2)

True airspeed is derived from Mach number (M) and speed of sound (a): VT = Ma .

(3)

Mach number is a dimensionless, recorded parameter. The speed of sound (a) is a function of pressure altitude (Hp) and the speed of sound at sea level and is a = a0 (1 − 6.876 × 10 −6 × H p )

(4)

Substituting equations 1 and 4 into equation 2 gives − − Ve = M × a0 × (1 − 6.876 × 10 6 × H p )0.5 × (1 − 6.876 × 10 6 × H p )2.128

(5)

and Ve = M × a0 × (1 − 6.876 × 10

−6

×Hp )

2.626

(6)

where the speed of sound at sea level a0 is 1116.4 fps or 661.5 knots. 4.3.3 Dynamic Pressure (q). The dynamic pressure (q) is calculated from the air density and velocity q= where

1 ρV 2 2

(7)

ρ = air density at altitude (slugs/ft3) V = true air speed (ft/sec)

4.3.4 Derived Gust Velocity (Ude). The derived gust velocity, Ude, is computed from the peak values of gust incremental normal acceleration as Δn z U de = (8) C where Δnz is gust peak incremental normal acceleration and C is the aircraft response factor considering the plunge-only degree of freedom and is calculated from

7

C=

ρ 0Ve CLα S 2W

Kg

(9)

where

ρ 0 = 0.002377 slugs/ft3, standard sea level air density Ve = equivalent airspeed (ft/sec) CLα = aircraft lift-curve slope per radian S = wing reference area (ft2) W = gross weight (lbs) 0.88 µ Kg = = gust alleviation factor 5.3 + µ 2W ρ gcCLα S

µ

=

ρ

= air density, slug/ft3, at pressure altitude (Hp), from equation 1

g c

= 32.17 ft/sec2 = wing mean geometric chord (ft)

In this program, the lift-curve slope, CLα , is the untrimmed flexible lift-curve slope for the entire airplane. For the flaps retracted conditions, the lift-curve slope is given as a function of Mach number and altitude; for flaps extended, the lift-curve slope is a function of flap deflection and calibrated airspeed (CAS). 4.3.5 Continuous Gust Intensity (Uσ). Power Spectral Density (PSD) functions provide a turbulence description in terms of the probability distribution of the root-mean-square (rms) gust velocities. The root-mean-square gust velocities, Uσ , are computed from the peak gust value of normal acceleration using the power spectral density technique as described in reference 2. The procedure is Uσ =

Δn z A

(10)

where Δnz = gust peak incremental normal acceleration A

= aircraft PSD gust response factor =

ρ0 VeC LαS 1 F(PSD) in ft/sec 2W

ρ0 = 0.002377 slugs/ft3, standard sea level air density Ve = equivalent airspeed (ft/sec) CLα = aircraft lift-curve slope per radian S = wing reference area (ft2) W = gross weight (lbs)

8

(11)

1

µ 11.8 c 3 , dimensionless F( PSD) = π 2 L 110 + µ

(12)

c = wing mean geometric chord (ft) L = turbulence scale length, 2500 ft µ=

2W , dimensionless ρgcCLα S

(13)

ρ = air density (slugs/ft3) g = 32.17 ft/sec2 To determine the number of occurrences (N) for Uσ , calculate

πc ρ N= = µ N0( o ) 203 ρ 0 N 0 ( o )ref

0 .4 6

, dimensionless

(14)

where c , ρ, ρ0, and µ are defined above. Then each Uσ peak is counted as N counts at that Uσ value. This number of counts is used to determine the number of counts per nautical mile (nm) or

counts N = nm distance flown in counting interval

(15)

Finally, the number of such counts is summed from the largest plus or minus value toward the smallest to produce the cumulative counts per nautical mile. 4.4 DATA REDUCTION CRITERIA. To process the measured data into statistical flight loads format, specific data reduction criteria were established for each parameter. These criteria are discussed in this section. 4.4.1 Phases of Flight. Each flight was divided into nine phasesfour ground phases (taxi out, takeoff roll, landing roll with and without thrust reverser, and taxi in), and five airborne phases (departure, climb, cruise, descent, and approach). Figure 3 shows these nine phases of a typical flight. The phases of flight were not defined by the airline but had to be determined from the data. Table 5 lists the conditions for determining the starting times for each phase. It should be noted that an airborne phase can occur several times per flight because it is determined by the rate of climb and the position of the flaps. When this occurs the flight loads data are combined and presented in a single flight phase. The UDRI software creates a file which chronologically lists the phases of flight and their corresponding starting times.

9

*Climb rate must be maintained for at least one minute before transition into another phase of flight takes place

FIGURE 3. DESCRIPTION OF PHASES OF FLIGHT

TABLE 5. PHASE OF FLIGHT STARTING CRITERIA

Phase of Flight Taxi Out Takeoff Roll Departure Climb Cruise Descent Approach Landing Roll Taxi In

Conditions at Start of Phase Initial condition Acceleration > 4 kts/sec for a minimum of 12 seconds Time at liftoff; flaps extended (squat switch off) Flaps retracted; rate of climb ≥ 250 ft/min. for at least 1 minute Flaps retracted; rate of climb ≤ 250 ft/min. for at least 1 minute Flaps retracted; rate of descent ≤ -250 ft/min. for at least 1minute Flaps extended; rate of descent < 250 ft/min. for at least 1 minute Touchdown; (squat switch on) Magnetic heading change greater than 13.5 degrees after touchdown or deviation from runway centerline greater than 100 feet

The criteria for the start of the takeoff roll have been redefined from those used in reference 3. In reference 3, the start of takeoff roll was defined as the time when the calibrated airspeed exceeded 50 knots and the longitudinal acceleration exceeded 0.15 g. It was found that in most cases when these criteria were met, the airplane had already been accelerating for 6 to 8 seconds and the initial portion of the takeoff roll was lost. The present criteria better defines the initial start of takeoff roll. When the acceleration remains above 4 knots per second for a minimum of 12 seconds, the takeoff roll phase begins. The criteria for the start of taxi in has also been redefined from the criteria used in reference 3. In reference 3 the start of taxi in was defined as the time when thrust reversers were stowed after initial deployment on landing. This definition did not account for cases when the thrust reversers are not deployed during the landing roll or the thrust reversers are stowed before or after the airplane turns off the active runway. In the new criteria, the start of taxi in has been redefined as the time when the aircraft turns off the active runway. The primary method for detecting turnoff is to monitor magnetic heading change for a change greater than 13.5 degrees from the landing

10

magnetic heading. The time when the heading starts to change in the turnoff direction is then identified as the start of the turn or the beginning of the taxi in phase. This method can fail to detect a shallow turnoff onto a parallel taxiway. In such cases a substitute criteria that identifies a lateral deviation greater than 100 feet from the landing centerline is used to detect the turnoff point. The criteria for determining the pitch angle at takeoff has been changed from that used in reference 3. In reference 3 the pitch angle at takeoff was defined as the maximum pitch angle occurring between 5 seconds before and 10 seconds after the squat switch moved from the closed to the open position. Using this time increment for selection of the pitch angle at takeoff results in pitch angles at the instant of takeoff that would cause the aircraft aft fuselage to strike the ground. For this report the pitch angle is defined as the angle occurring just prior to the squat switch change. 4.4.2 Flight Distance. The flight distance can be obtained either by determining the stage length of the flight or by integrating the range with respect to changes in aircraft velocity as a function of time. The stage length is defined as the distance from departure airport to destination airport and is determined as the great circle distance in nautical miles between the point of liftoff (departure) and the point of touchdown (destination). Appendix B describes the calculation of great circle distance. The time histories of longitude and latitude are matched against the UDRI generated phase of flight file to determine the geographical location of the aircraft at the point of liftoff and the point of touchdown. The integrated flight distance D is obtained by the numerical integration from the time at liftoff (t0) to the time of touchdown (tn), and V is the average velocity during Δt. tn

D = ∑ Δt ⋅ V

(16)

t0

4.4.3 Sign Convention. Acceleration data are recorded in three directions: normal (z), lateral (y), and longitudinal (x). As shown in figure 4, the positive z direction is up; the positive y direction is airplane starboard; and the positive x direction is forward.

11

z Up y

Starboard

x Forward

Parallel to Fuselage Reference Line

FIGURE 4. SIGN CONVENTION FOR AIRPLANE ACCELERATIONS 4.4.4 Peak-Valley Selection. The peak-between-means method presented in reference 2 was used to select the peaks and valleys in the acceleration data. This method is consistent with past practices and pertains to all accelerations (nx, ny, Δnz, Δnzman , Δnzgust ). Figure 5 depicts an example of the peak-between-mean criteria. This method counts upward events as positive and downward events as negative. Only one peak or one valley is counted between two successive crossings of the mean. A threshold zone is used in the data reduction to ignore irrelevant loads variations around the mean. For the normal accelerations Δnz, Δnzgust , and Δnzman , the threshold zone is ±0.05 g; for lateral acceleration ny, the threshold zone is ±0.005 g; and for longitudinal accelerations nx, the threshold zone is ±0.0025 g. Mean Crossing !⊕ Classified Peak ο Classified Valley

√

}Deadband Threshold Zone

FIGURE 5. THE PEAK-BETWEEN-MEANS CLASSIFICATION CRITERIA

12

A peak is generated only when the acceleration data cross into or through the deadband. Two situations must be considered: the position of the current acceleration value relative to the deadband and the position of the previous acceleration value relative to the deadband. In the peak-between-means counting algorithm, the previous acceleration value is that value in a consecutive set of values all of which lie either above the deadband or below the deadband. The previous value is established as a peak when the current value has crossed into or through the deadband. Figures 6a and 6b demonstrate the concept of current and previous acceleration values. In figure 6a the current acceleration value passes into the deadband, whereas in figure 6b the current value passes through the deadband.

FIGURE 6a. CURRENT ACCELERATION VALUE PASSES INTO DEADBAND

FIGURE 6b. CURRENT ACCELERATION VALUE PASSES THROUGH DEADBAND

Italicized text in table 6 summarizes the action(s) taken when the various possibilities occur. Note that when a previous acceleration value is retained as a potential peak, its coincident time is also retained. 4.4.5 Separation of Maneuver and Gust Load Factors. The recorded normal acceleration (nz) values included the 1 g flight condition. The 1 g condition was removed from each nz reading which was then recorded as Δnz. In order to avoid the inclusion of peaks and valleys associated with nonsignificant small load variations, a threshold zone of Δnz = ±0.05 g was established. An algorithm was then developed to extract the acceleration peaks and valleys. For each flight, the maximum and minimum total accelerations were determined from just after liftoff to just before touchdown. For the five in-flight phases, the Δnz cumulative occurrences were determined as cumulative counts per nautical mile and cumulative counts per 1000 hours using the peak-between-means counting method of reference 2 explained in section 4.4.4. The incremental acceleration measured at the center of gravity (c.g.) of the aircraft may be the result of either maneuvers or gusts or a combination of both. In order to derive gust statistics, the maneuver induced acceleration is separated from the total acceleration history. Most maneuver induced loads are associated with turning maneuvers.

13

TABLE 6. PEAK CLASSIFICATION CRITERIA

Previous Acceleration Value Relative to Deadband

Above Previous value is potential positive peak

Within At start of processing, or a peak was established but current acceleration value has not since gone outside of deadband

Below Previous value is potential negative peak

Current Acceleration Value Relative to Deadband Below Within Above Current acceleration is on Current acceleration passes Current acceleration same side of deadband as passes into deadband. through deadband. Previous value classified as Previous value classified previous. If current > previous as a positive peak. a positive peak. value, retain current value Current value retained as a Acceleration value as potential positive peak flagged as being in potential negative peak. and release previous. deadband. Current acceleration Current acceleration passes passes upward out of downward out of deadband. No Action Current value is retained as deadband. Current value retained as Required a potential negative peak. potential positive peak. Current acceleration passes into deadband. Previous value is established as a negative peak. Acceleration value flagged as being in deadband.

Current acceleration is on same side of deadband as previous. If current value < previous value, retain current value as potential negative peak and release previous value.

Current acceleration passes through deadband. Previous value is classified as a negative peak. Current value retained as potential positive peak.

The increment due to a turning maneuver (Δm) is determined using the bank angle method discussed in reference 2 to calculate the maneuver acceleration Δnzman as Δnzman = ( sec ϕ -1)

(17)

where ϕ is the bank angle. The remaining peaks and valleys are assumed to be gust induced, where gust normal acceleration ( Δnz gust ) is calculated as Δnz gust =Δ nz − Δ nz man

(18)

This approach does not separate the pitching maneuvers induced by pilot control inputs. In reference 2, J.B. de Jonge suggests that accelerations resulting from pitch maneuvers induced by pilot input to counteract turbulence can be considered as part of the aircraft system response to the turbulence. Accelerations that are induced by the pitch maneuver at the specific points of rotation and flare during takeoff and climb and approach and touchdown have not been removed during this initial data reduction effort. Since turbulence is a more dominant loading input on commercial aircraft than maneuvers, correcting for pitch maneuvers at a later time will not substantially alter the statistics presented herein. Once calculated, the measurements of Δnz, Δnzgust , and Δnzman are maintained as three unique data streams.

The Δnzgust and Δnzman data are plotted as cumulative occurrences of a given

acceleration fraction per nautical mile and per 1000 flight hours. Separate plots are provided for each phase of flight and all phases combined. The Δnz fraction is the recorded incremental 14

normal load factor (airplane limit load factor minus 1.0 g). As a result of the threshold zone, only accelerations greater than ±0.05 g (measured from a 1.0 g base) are counted for data presentation. 4.4.6 Flap Detents. When flaps are extended, the effective deflection is considered to be that of the applicable detent, as indicated in table 7. The flap deflection ranges and placard speeds reflect the flap design and cockpit placards. TABLE 7. FLAP DETENTS (B-737-400) Flap Detent

Minimum Flap Setting

Maximum Flap Setting

Design Placard Speed (KIAS)

Cockpit Placard Speed (KIAS)

1 5 10 15 25 30 40 45

>0 > 0.5 >5 > 10 > 15 > 25 > 30 >40

< 0.5 <5 < 10 < 15 < 25 < 30 < 40

250 250 218 213 206 199 162 162

250 250 215 205 190 185 162 162

5. DATA PRESENTATION. Table 8 lists the statistical data presentation formats for which data was processed and included in appendix A of this report. Similar statistical loads data, but of a reduced scope and based on fewer flights for a single aircraft, were previously presented in reference 3. To facilitate comparisons of the present data formats with this earlier data, the data formats available in reference 3 are identified by an asterisk in the listings of table 8. Figures A-1 through A-83 present the processed data. It will be noted that the data presented in these figures are not always based on an identical number of flights. During data reduction it was found that the acceleration measurements in certain flights exhibited random errors and were unreliable. When this occurred, those flights were eliminated from the statistical data for any parameters associated, directly or indirectly, with the unreliable acceleration measurements. As a result, not all figures are based on data from identical numbers of flights, hours, or nautical miles. 5.1 AIRCRAFT OPERATIONAL USAGE DATA. The aircraft usage data include flight profile statistics such as weights, altitudes, speeds, and flight distance information. This information is useful in the derivation of typical flight profiles and in defining ground-air-ground cycles for structural durability, damage tolerance analyses, future design criteria, and for use in the analysis of airline operating economics. Aircraft usage data are presented in figures A-1 through A-12. 15

TABLE 8. STATISTICAL DATA FORMATS

Data Description

Figure

AIRCRAFT USAGE DATA WEIGHT DATA Cumulative Probability of Takeoff Gross Weight Cumulative Probability of Takeoff Fuel Weight Cumulative Probability of Landing Gross Weight Correlation of Takeoff Fuel Weight and Flight Distance, Percent of Flights Correlation of Takeoff Gross Weight and Flight Distance, Percent of Flights Correlation of Gross Weight at Liftoff and Touchdown, Percent of Flights * ALTITUDE DATA Correlation of Maximum Altitude and Flight Distance, Percent of Flights Percent of Total Distance in Altitude Bands Coincident Altitude at Maximum Mach Number, Cruise Phase Coincident Altitude at Maximum Equivalent Airspeed, Cruise Phase Coincident Altitude at Maximum Mach Number, All Flight Phases Coincident Altitude at Maximum Equivalent Airspeed, All Flight Phases FLIGHT DISTANCES Cumulative Probability of Flight Distances AUTOPILOT OPERATION * Cumulative Probability of Percent of Flight Time on Autopilot

A-1 A-2 A-3 A-4 A-5 A-6 A-7 A-8 A-9a A-9b A-10a A-10b A-11 A-12

GROUND LOADS DATA LATERAL LOAD FACTOR, ny Cumulative Frequency of Maximum Side Load Factor During Ground Turns LONGITUDINAL LOAD FACTOR, nx Cumulative Frequency of Longitudinal Load Factor During Ground Taxi Cumulative Frequency of Longitudinal Load Factor During Landing Roll Cumulative Probability of Maximum Longitudinal Load Factor During Takeoff Cumulative Probability of Minimum Longitudinal Load Factor During Landing VERTICAL LOAD FACTOR, nz Cumulative Frequency of Incremental Vertical Load Factor During Taxi Operations Cumulative Frequency of Incremental Vertical Load Factor During Takeoff Roll Cumulative Frequency of Incremental Vertical Load Factor During Landing Roll Cumulative Probability of Minimum and Maximum Incremental Vertical Load Factor at Touchdown and Spoiler Deployment * Coincident Incremental Vertical Load Factor and Touchdown Gross Weight GROUND SPEED DATA Cumulative Probability of Ground Speed During Taxi Cumulative Probability of Airspeed at Liftoff and Touchdown * FLARE DATA Cumulative Probability of Airspeed at Flare PITCH/ROTATION DATA Cumulative Probability of Pitch Angle at Liftoff and Touchdown * Cumulative Probability of Maximum Pitch Rate at Takeoff Rotation * Cumulative Probability of Pitch Angle at Touchdown Peak Vertical Load Factor * *Denotes data formats from reference 3.

16

A-13 A-14 A-15 A-16 A-17 A-18 A-19 A-20 A-21 A-22 A-23 A-24 A-25 A-26 A-27 A-28

TABLE 8. STATISTICAL DATA FORMATS (Continued) Data Description

Figure

FLIGHT LOADS DATA GUST LOADS DATA Cumulative Occurrences of Vertical Gust Load Factor per 1000 Hours by Flight Phase Cumulative Occurrences of Incremental Vertical Gust Load Factor per 1000 Hours, Combined Flight Phases Cumulative Occurrences of Vertical Gust Load Factor per Nautical Mile by Flight Phase Cumulative Occurrences of Incremental Vertical Gust Load Factor per Nautical Mile, Combined Flight Phases Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, < 500 Feet Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, 500-1,500 Feet Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, 1,500-4,500 Feet Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, 4,500-9,500 Feet Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, 9,500-19,500 Feet Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, 19,500-29,500 Feet Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, 29,500-39,500 Feet Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, Flaps Extended Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, Flaps Retracted Cumulative Occurrences of Continuous Gust Intensity per Nautical Mile, Flaps Extended Cumulative Occurrences of Continuous Gust Intensity per Nautical Mile, Flaps Retracted MANEUVER LOADS DATA Cumulative Occurrences of Incremental Maneuver Load Factor per 1000 Hours During Departure by Altitude Cumulative Occurrences of Incremental Maneuver Load Factor per 1000 Hours During Climb by Altitude Cumulative Occurrences of Incremental Maneuver Load Factor per 1000 Hours During Cruise by Altitude Cumulative Occurrences of Maneuver Load Factor per 1000 Hours During Descent by Altitude Cumulative Occurrences of Maneuver Load Factor per 1000 Hours During Approach by Altitude Cumulative Occurrences of Maneuver Load Factor per Nautical Mile During Departure by Altitude Cumulative Occurrences of Maneuver Load Factor per Nautical Mile During Climb by Altitude Cumulative Occurrences of Maneuver Load Factor per Nautical Mile During Cruise by Altitude Cumulative Occurrences of Maneuver Load Factor per Nautical Mile During Descent by Altitude Cumulative Occurrences of Maneuver Load Factor per Nautical Mile During Approach by Altitude Cumulative Occurrences of Maneuver Load Factor per 1000 Hours by Flight Phase Cumulative Occurrences of Maneuver Load Factor per 1000 Hours, Combined Flight Phases Cumulative Occurrences of Maneuver Load Factor per Nautical Mile by Flight Phase Cumulative Occurrences of Maneuver Load Factor per Nautical Mile, Combined Flight Phases COMBINED MANEUVER AND GUST LOADS DATA * Cumulative Occurrences of Combined Maneuver and Gust Vertical Load Factor per 1000 Hours by Flight Phase Cumulative Occurrences of Vertical Load Factor per 1000 Hours, Combined Flight Phases Cumulative Occurrences of Vertical Load Factor per Nautical Mile by Flight Phase Cumulative Occurrences of Vertical Load Factor per Nautical Mile, Combined Flight Phases Cumulative Occurrences of Lateral Load Factor per 1000 Hours, Combined Flight Phases Coincident Maneuvers Load Factor and Speed Versus V-n Diagram for Flaps Retracted Coincident Maneuvers Load Factor and Speed Versus V-n Diagram for Flaps Extended Coincident Gust Load Factor and Speed Versus V-n Diagram for Flaps Retracted Coincident Gust Load Factor and Speed Versus V-n Diagram for Flaps Extended *Denotes data formats from reference 3.

17

A-29 A-30 A-31 A-32 A-33 A-34 A-35 A-36 A-37 A-38 A-39 A-40 A-41 A-42 A-43 A-44 A-45 A-46 A-47 A-48 A-49 A-50 A-51 A-52 A-53 A-54 A-55 A-56 A-57 A-58 A-59 A-60 A-61 A-62 A-63 A-64 A-65 A-66

TABLE 8. STATISTICAL DATA FORMATS (Continued) Data Description

Figure

MISCELLANEOUS OPERATIONAL DATA FLAP USAGE DATA Cumulative Probability of Maximum Airspeed in Flap Detent During Departure Cumulative Probability of Maximum Airspeed in Flap Detent During Approach Percent of Time in Flap Detent During Departure Percent of Time in Flap Detent During Approach Cumulative Probability of Maximum Dynamic Pressure in Flap Detent During Departure Cumulative Probability of Maximum Dynamic Pressure in Flap Detent During Approach SPEED BRAKE/FLIGHT SPOILER DATA Cumulative Probability of Maximum Speed During Speed Brake Deployment Cumulative Frequency of Speed at Speed Brake Deployment Cumulative Frequency of Altitude at Speed Brake Deployment Cumulative Probability of Maximum Deployment Angle During Speed Brake Deployment, Flaps Retracted THRUST REVERSER DATA Cumulative Probability of Time With Thrust Reversers Deployed Cumulative Probability of Speed at Thrust Reverser Deployment and Stowage

A-67 A-68 A-69 A-70 A-71 A-72 A-73 A-74 A-75 A-76

A-77 A-78

LANDING GEAR EXTENSION/RETRACTION DATA Cumulative Probability of Time With Landing Gear Extended After Liftoff Cumulative Probability of Time With Landing Gear Extended Prior to Touchdown Cumulative Probability of Maximum Airspeed With Gear Extended

A-79 A-80 A-81

PROPULSION SYSTEM DATA Cumulative Probability of Percent of N1 at Takeoff Cumulative Probability of Percent of N1

A-82 A-83

*Denotes data formats from reference 3.

5.1.1 Weight Data. Statistical data on operational takeoff gross weights, landing gross weights, and fuel weights are presented in this section. These weights are also correlated to flight distance. The cumulative probabilities of takeoff gross weight, takeoff fuel weight, and landing weight are presented in figures A-1 through A-3 respectively. The correlation between fuel weight at takeoff and the flight distance is presented in figure A-4. A similar correlation for takeoff gross weight and flight distance is shown in figure A-5. The flight distances in figures A-4 and A-5 are based on the great circle distance between departure and arrival points. It is interesting to note that the small difference in the number of flights between figures A-4 and A-5 has an insignificant impact on the flight distance distribution as indicated by a comparison of the numbers in the right end columns of these figures. Figure A-6 provides the correlation between the takeoff gross weight and the landing gross weight. The correlation shows that for most flights with light takeoff weights (less than 100,000 pounds) the landing weight is within 10,000 pounds of the takeoff weight. For the medium takeoff weights from 100,000-130,000 pounds the landing weights are from 10,000-20,000 pounds below takeoff weight. For the heavy weight takeoffs from 130,000-150,000 pounds the landing weights are from 20,000-30,000 pounds below the takeoff weight.

18

5.1.2 Altitude Data. Measured operational altitudes and their correlation to flight distance and maximum speed are presented. Figure A-7 shows the correlation between the maximum altitude attained in flight and the flight distance flown in percent of flights. The data show that for short flights of less than 250 nautical miles, the maximum altitude is generally below 30,000 feet with the most flights occurring from 20,000-25,000 feet. For flights from 250-500 nautical miles the altitude may range from 25,000 to 40,000 feet, while for flights above 500 nautical miles the maximum altitude can be considered above 30,000 feet. Figure A-8 presents the percent of total flight distance spent in various altitude bands as a function of flight distance. The flight distances in figure A-7 reflect the stage lengths, whereas the flight distances in figure A-8 are based on the numerical integration approach mentioned in paragraph 4.4.2. The combined information in figures A-7 and A-8 provide a comprehensive picture of the flight profile distribution. Figures A-9a and A-9b show the coincident altitude at the maximum Mach number and the maximum equivalent airspeed attained in the cruise phase of the flights respectively. Figures A-10a and A-10b show the maximum Mach number or the maximum equivalent airspeed with respect to the design cruise limit regardless of flight phase. In other words, the speed that most closely approached the speed limit in a flight was identified as the maximum speed. As an example, in one flight the maximum speed with respect to the limit might have been attained in the climb phase, while in another flight the maximum speed with respect to the limit speed might have occurred in the cruise phase. The data in figures A-10a and A-10b are fairly evenly distributed between the climb, cruise, and descent phases with only a single occurrence in the departure and approach phases. The design speed limits are also shown in the figures. It should be noted that maximum Mach number and maximum equivalent airspeed do not necessarily occur simultaneously. 5.1.3 Flight Distance Data. Flight distance statistics useful in the generation of flight profiles were derived and are presented here. The cumulative probability of flight distances flown is presented in figure A-11. The great circle distance reflects the ground distance between two points as obtained from the great circle distance calculation, but does not necessarily reflect the actual distance flown. Deviation from direct flight between departure and arrival points resulting from traffic control requirements will increase the actual distance flown by some unknown amount. To a much lesser extent, the climb and descent distances are slightly larger than the level flight distance. Head or tail winds also are unknown contributors. The integrated distance accounts for such variables. The figure provides a graphical presentation of the differences in flight distance obtained by the two approaches. 5.1.4 Autopilot Usage. Autopilot usage is determined by the operational procedures employed. Figure A-12 shows the cumulative probability of percent flight time flown on autopilot. Comparison with the autopilot data presented in reference 3 shows that autopilot usage has increased significantly.

19

5.2 GROUND LOADS DATA. The ground loads data include frequency and probability information on vertical, lateral, and longitudinal accelerations, speeds, and pitch rotation associated with takeoff, landing, and ground operations. These data are of primary importance to landing gear and landing gear backup structure and to a lesser extent to the wing, fuselage, and empennage. 5.2.1 Lateral Load Factor Data. Lateral load factor statistics resulting from ground turning during taxi were derived and are presented. Figure A-13 shows the cumulative frequency of maximum side load factor during ground turns. The information is presented for preflight and postflight taxi, as well as, left and right turns. The turning load factors during taxi in are shown to be more severe than those experienced during turning while taxiing out. This is likely the result of higher taxi in speed as shown in figure A-23. There is no significant difference between the number of left and right turns. 5.2.2 Longitudinal Load Factor Data. Longitudinal load factor statistics were derived for all phases of ground operation, including preflight and postflight taxi, and takeoff and landing roll. Figures A-14 and A-15 present the cumulative frequency of longitudinal load factor during ground operations. Figure A-14 shows the data for pre- and postflight taxi. The higher number of occurrences of negative longitudinal load factor less than –0.15 g during the taxi in phase are possibly due to braking action occurring at the higher taxi in speeds. Figure A-15 shows the landing rollout with and without thrust reverser deployment. Figures A-16 and A-17 present the cumulative probability of the maximum longitudinal load factor measured during the takeoff and landing rolls respectively. 5.2.3 Vertical Load Factor Data. Vertical load factor statistics during all phases of ground operation with and without thrust reverser were derived and are presented. Figure A-18 presents the cumulative frequency of incremental vertical load factor during preflight and postflight taxi. Figure A-19 presents the cumulative frequency of incremental vertical load factor during the takeoff roll, while Figure A-20 presents the cumulative frequency of incremental vertical load factor during the landing roll for operation with and without thrust reverser. As can be seen there is little difference in the frequency of vertical load factor occurrences resulting from taxi, takeoff roll, and landing roll except for positive occurrences during landing without thrust reverser. It is noteworthy (see figure A-15) that there is also increased longitudinal load factor activity during landing without thrust reversers. Figure A-21 presents the cumulative probability of the minimum and maximum incremental vertical load factors associated with touchdown and ground spoiler deployment. As can be seen the minimum load factors measured at spoiler deployment remain positive. Figure A-22 shows the coincident incremental vertical load factor and gross weight at touchdown for all flights.

20

5.2.4 Ground Speed Data. The cumulative probabilities of ground speed for taxi in and taxi out operations are presented in figure A-23. The taxi in speeds are seen to be considerably higher than the taxi out speeds. There can be several reasons for this difference. First, the airplane may still be moving at a fairly high speed shortly after turning off the active runway. Departure from the active runway has been used as the criterion for start of taxi in. Second, movement of inbound traffic to the terminal after landing is generally accomplished faster than similar movement from the terminal to the takeoff position. Figure A-24 shows the cumulative probabilities of airspeed at liftoff and touchdown rotation. The liftoff speeds are approximately 20 knots higher than the touchdown speeds. The figure indicates that a considerable number of touchdowns are performed at speeds well above published stall speeds. 5.2.5 Flare Data. Figure A-25 presents the cumulative probability of airspeed at flare. Since the actual instant of flare is difficult to determine with any great accuracy, the start of flare was assumed to occur 3 seconds prior to main gear squat switch closure. 5.2.6 Pitch/Rotation Data. The cumulative probability of maximum pitch angle at takeoff and landing is presented in figure A-26. The pitch angles for takeoff presented in this figure are considerably lower than those previously reported in reference 3. It has been determined that the time increment previously used for selecting the pitch angle at takeoff was too long, resulting in pitch angles at the instant of takeoff that would have resulted in the aircraft aft fuselage striking the ground. This increment was reduced for the present data reduction effort as discussed in section 4.4.1. Figure A-27 presents the cumulative probability of maximum takeoff pitch rate at takeoff rotation. Figure A-28 presents the cumulative probability of pitch angle that occurs at touchdown peak vertical load factor. 5.3 FLIGHT LOADS DATA. The flight loads data include the statistical data that describe the gust and maneuver environment. The gust environment is presented in the form of cumulative occurrences of derived gust velocity, continuous gust intensity, and vertical load factor. The derived gust velocity and continuous gust intensity are computed values as described in section 4.3. Since the 1950’s, it has been common practice to present flight loads data as cumulative occurrences. Data that were previously recorded on the B-737 are reported in references 4 and 5 as cumulative occurrences per 1000 hours. To compare to data from different references, the normal acceleration data are plotted two ways, as cumulative occurrences per 1000 hours and as cumulative occurrences per nautical mile. 5.3.1 Gust Loads Data. The gust data are presented in the form of derived gust velocity Ude and continuous gust intensities Uσ. Figure A-29 presents the cumulative occurrences of incremental vertical gust

21

load factor per 1000 hours. The data are presented by phase of flight. Figure A-30 shows cumulative occurrences of incremental vertical gust load factor for the total combined airborne phases per 1000 hours. Figure A-31 presents the cumulative occurrences of incremental vertical gust load factor per nautical mile by phase of flight, and figure A-32 shows the cumulative occurrences of incremental vertical gust load factor for the total combined airborne phases per nautical mile. In figures A-33 through A-39 the derived gust velocity Ude is plotted as cumulative counts per nautical mile for altitudes from sea level to 39,500 feet. Figures A-40 and A-41 present the derived gust velocity Ude as cumulative counts per nautical mile with flaps extended and retracted respectively. 5.3.2 Maneuver Loads Data. The technique used to identify maneuvers assumes that maneuvers are associated primarily with turning conditions and that the impact of pitch maneuvers is insignificant and can be ignored. As a result, maneuvers resulting from push down or pull up maneuvers are ignored and only positive maneuver load factors resulting from banked turns are identified. Figures A-44 through A-48 present the cumulative occurrences of maneuver load factor per 1000 hours by altitude for each of the airborne flight phases, i.e., departure, climb, cruise, descent, and approach. Figures A-49 through A-53 present the cumulative occurrences of maneuver load factor by altitude per nautical mile in the airborne phases of flight. Figure A-54 presents the total cumulative occurrences of incremental maneuver load factor per 1000 hours for each phase of flight, regardless of altitude. Figure A-55 presents the total cumulative occurrences of incremental maneuver load factor per 1000 hours for all flight phases combined. Figure A-56 presents the total cumulative occurrences of incremental maneuver load factor per nautical mile for each phase of flight regardless of altitude. Figure A-57 presents the total cumulative occurrences of incremental maneuver load factor per nautical mile for all flight phases combined. The maneuver data presented in this report extend beyond load factor magnitudes available in reference 3. However, at identical load factor levels, the data trends between this report and reference 3 are quite similar. 5.3.3 Combined Maneuver and Gust Loads Data. For the data presented in this section, the maneuver and gust load factors were not separated, but the total load factor occurrences regardless of the cause were used in the derivation of the figures. Figure A-58 shows the cumulative occurrences of total combined maneuver and gust normal load factor per 1000 hours by phases of flight, and figure A-59 shows the occurrences for all phases combined. Figures A-60 and A-61 show the data of figures A-58 and A-59 as occurrences per nautical mile. Federal Aviation Regulation (FAR) 25.333 requires that airplane structural operating limitations be established at each combination of airspeed and load factor on and within the boundaries of maneuvering and gust load envelopes (V-n diagrams). For purposes of displaying the coincident maneuver or gust accelerations, four representative V-n diagrams were developed from the FAR requirements.

22

The required limit load factors for maneuvers are specified in FAR 25.337. The positive limit maneuvering load factor (n) may not be less than 2.5, and the negative limit maneuvering load factor may not be less than -1.0 at speeds up to VC , varying linearly with speed to zero at VD. FAR 25.345 specifies that the positive limit maneuver load factor is 2.0 g when the flaps are extended. The stall curve on the left side of the envelopes is determined by the maximum lift coefficient. The curve was estimated by using the 1 g stall speed to estimate CLmax . The required limit load factors for gusts result from gust velocities as specified in FAR 25.341. The FAR specifies positive (up) and negative (down) air gust design requirements for three different aircraft design speeds: maximum gust intensity (VB), cruising speed (VC), and dive speed (VD). Between sea level and 20,000 feet, the gust requirement is constant, varying linearly to the value given for 50,000 feet. FAR 25.345 sets a requirement of positive, negative, and head-on for 25 fps gusts when flaps are extended. These gust design requirements are shown in table 9. TABLE 9. FAR REQUIREMENTS FOR DERIVED DISCRETE GUST VELOCITIES Gust Velocity Aircraft Design Speed VB VC VD Flaps Extended

0-20,000 Feet Altitude 66 fps 50 fps 25 fps 25 fps

50,000 Feet Altitude 38 fps 25 fps 12.5 fps

Sufficient data to generate V-n diagrams for all weight and altitude conditions were not available. Therefore, sea level data were used to develop the representative diagrams, and all of the recorded maneuvers and gusts were plotted on these. A weight of 90,000 lbs., the lowest recorded weight, was used for the calculations required in developing these diagrams. Figure A-63 through A-66 shows the V-n diagrams for maneuver and for gust with flaps retracted and extended. Coincident acceleration and speed measurements are also plotted on the V-n diagrams. As can be seen in figure A-66, a large number of gust accelerations occurred outside the gust V-n diagram for the flaps extended case. 5.4 MISCELLANEOUS OPERATIONAL DATA. The miscellaneous operational data includes statistical usage information for flaps, speed brake/spoilers, thrust reversers, and landing gear operations. Although aileron and rudder deflection information was available it was not processed because it was deemed that the slow sampling rates prevented the reduction of reliable statistical usage information for these components.

23

5.4.1 Flap Usage Data. Flap usage statistics of value in the design of flap structure, backup structure, and other flap components were reduced from the measured data. Figure A-67 presents the cumulative probability of maximum airspeed encountered in various flap detents during the departure phase of the flights. The flap detents are defined in table 7. The single points for detents 40 and 45 at 160 knots indicate a single occurrence of these settings during departure. Figure A-68 presents similar data for the approach phase of the flights. Figures A-69 and A-70 present the percent of time spent in various flap detents during the departure and approach phases of flight, respectively. As shown in figure A-69, flap detent 5 was the detent used in almost all cases during departure. Previous data presented in reference 6 showed that detent 1 was used approximately one-third of the total time. Discussion with the airline confirmed that a change in flap operating procedure for departure had occurred between the two reporting periods. Comparison of the data in figure A-70 with similar data in reference 5 shows that although changes in flap usage for approach had occurred, these changes were not as dramatic as those seen for the departure phase. Figures A-71 and A-72 show the cumulative probability of maximum dynamic pressure encountered while in different flap detents for the departure and approach phases respectively. The single points for detents 40 and 45 in figure A-71 indicate a single occurrence of these settings during departure. 5.4.2 Speed Brake/Spoiler Usage Data. Information on speed brake operations during flight was determined to be of primary interest to various users of the data. Therefore, statistics on speed brake usage as a function of speed, altitude, and deflection angle were derived from the measured data. To be counted as a deployment cycle the speed brake had to deflect more than 7 degrees for a period of 3 seconds. Data on spoiler operations occurring during the landing roll are available, but were not reduced into statistical format. Figure A-73 presents the cumulative occurrences of maximum speed encountered while the speed brakes were deployed, while figure A-74 presents the cumulative occurrences of speed at the moment of speed brake deployment. Figure A-75 presents the cumulative occurrences of altitude at the moment of speed brake deployment. Figure A-76 presents the cumulative probability of maximum deployment angle reached during the time that the speed brakes were deployed for the flaps retracted configuration. As can be seen in figures A-73 through A-76 speed brake cycles occur on average less than once per flight. Speed brake cycles occurred but were not counted for the conditions of flaps deflected in various detents. 5.4.3 Thrust Reverser Data. Cumulative probabilities of duration and speed associated with thrust reverser operations were derived from the measured data. Figure A-77 presents the cumulative probability of total time that thrust reversers are deployed. Figure A-78 presents the cumulative probability of the speed at the time when the thrust reversers were deployed or stowed. Although normally the thrust reversers are deployed and stowed a single time for each landing, the measured data showed two cycles of thrust reverser operation on a few occasions. This accounts for the rare occurrence of thrust reverser deployment at speeds as low as 45 knots in figure A-78. The data processing did not evaluate the engine power lever angles existing at these specific low-speed thrust reverser 24

deployments. However, at such low speeds, exhaust gas re-ingesting becomes a concern. Normally the engine manufacturer specifies a thrust reverser cutoff speed, typically about 50 knots, below which thrust reversers should not be used. 5.4.4 Landing Gear Extension/Retraction Data. Landing gear operating statistics were reduced from the measured data. The information can be used to support design, evaluation, and monitoring of the landing gear and associated structure. Figure A-79 shows the cumulative probability of total time with the landing gear extended after liftoff. Figure A-80 shows the cumulative probability of time with the landing gear extended prior to touchdown. As is expected, the time with gear extended during approach is considerably longer than the time after liftoff when the pilot retracts the gear within seconds after liftoff. Figure A-81 presents the cumulative probability of the maximum airspeed during the time that the gear is extended for both the departure and approach phases of flight. 5.5 PROPULSION SYSTEM DATA. The cumulative probability of engine fan speed N1 associated with thrust reverser operations was derived from the measured N1 engine parameter. Figure A-82 presents the cumulative probability of engine fan speed N1 at takeoff, at thrust reverser deployment, and the maximum fan speed N1 encountered during the time that the thrust reverser is deployed. 6. CONCLUSIONS. Incorporation of the additional data formats provides new and informative statistical information to the aircraft manufacturers, airlines, and the FAA. Comparison of the gust load factor occurrence data of this report based on 13,916 hours with the same data based on 817.7 hours in reference 3 shows general agreement for incremental load factor levels to plus or minus 0.5 g. At higher load factors the new data shows reduced occurrence levels, indicating that the extrapolation of limited data samples may lead to erroneous results. An identical conclusion is drawn when comparing the maneuver load factor results. The FAA goal is to collect a minimum of recorded flight hours equal to one design life to provide a reliable database. It would seem prudent to continue the data gathering for some time, until a stable database is obtained. The autopilot and flap usages presented in this report differ significantly from earlier usages presented in reference 3. This suggests that the operational procedures employed change over time. Changes in operational procedures would be expected to apply to all identical aircraft in the airline fleet. To track the impact of such changes a single representative aircraft should remain installed with a flight loads recorder throughout its life. The data in figure A-66 shows that the measured gust load factors for the flaps extended configuration often occur outside the design V-n diagram. The data suggests that the present gust design requirements for the flaps extended configuration may need to be reviewed for adequacy. An assessment of the appropriateness of the continued use of Ude values specified in FAR 25.345 for high-lift devices appears to be justified. Derived gust velocity, Ude, values 25

obtained from this effort show deviation from the data presented in reference 6. In general, for altitudes below 1,500 feet the B-737–400 data show higher levels of occurrences for the upward gusts and fewer for the downward gusts than presented in reference 6. For the altitude range from 1,500-9,500 feet the occurrences from the B-737-400 compare very well with the reference 6 data. For levels above 9,500 feet the B-737-400 occurrences are below those predicted by reference 6. In as much as reference 6 represented a rather preliminary effort to define atmospheric turbulence in power spectral format, the B-737-400 data should also be compared to other study results to provide a more complete assessment of the B-737-400 data and its influence on future design requirements. Furthermore, calculation of turbulence field parameters, P and b values, based on the B-737-400 data is considered desirable and should be included in future data reduction efforts. The resulting values should be compared with turbulence field parameters specified in reference 6 and Appendix G to Part 25 of the FAR. The technique used in this report to separate gust and maneuver accelerations results in positive maneuver occurrences only. The most common method previously used to separate maneuver and gust accelerations has been the so called 2-second rule. From reviews of measured data and studies of aircraft response to elevator motion it was determined that for larger aircraft essentially all of the maneuver load factor peaks can be expected to be counted if a time between zero crossings greater than 2 seconds is used. Load factor peaks with zero crossings less than 2 seconds will mostly all be gusts. This approach resulted in the identification of both positive and negative maneuver occurrences. A cursory review of the B-737-400 acceleration data shows that pitching maneuvers resulting in both positive and negative accelerations do occur with some frequency and magnitude in the climb phase. Unfortunately these occurrences are counted as gusts. A study to evaluate the impact of different maneuver and gust separation criteria is very important and should be done before much is made of the differences in the gust frequencies noted and before turbulence field parameters are derived. Statistical information on flight control surface activity is a valuable input to the design requirements for these surfaces and their associated components. Flight control surface deflections are recorded at two samples per second (2 sps) and can easily be reduced to provide the desired information. Unfortunately, there are doubts about the adequacy of the sampling rates to provide reliable results. For this reason the flight control surface deflection data were not processed. A study to determine the sampling rates as a function of control surface deflection rate necessary to provide acceptable statistical surface deflection information would be invaluable.

26

7. REFERENCES. 1.

Crabill, Norman L., “FAA/NASA Prototype Flight Loads Program Systems Requirements, B737-400 Aircraft,” Eagle Aerospace Inc., Contract NAS1-19659, unpublished report, November 1994.

2.

de Jonge, B., “Reduction of Incremental Load Factor Acceleration Data to Gust Statistics,” DOT/FAA/CT-94/57, August 1994.

3.

“Flight Loads Data for a Boeing 737-400 in Commercial Operation,” Department of Transportation Report DOT/FAA/AR-95/21, April 1996.

4.

“Data From Unusual Events Recording System in a Commercial 737 Aircraft,” Technology Incorporated Instruments and Controls Division, Dayton OH, Report No. FAA-RD-72-113, November 1972.

5.

Clay, Larry E., DeLong, Robert C., and Rockafellow, Ronald I., “Airline Operational Data From Unusual Events Recording Systems in 707, 727, and 737 Aircraft,” Report No. FAA-RD-71-69, September 1971.

6.

Press, Harry and Steiner, Roy, “An Approach to the Problem of Estimating Severe and Repeated Gust Loads for Missile Operations,” National Advisory Committee for Aeronautics Technical Note 4332, September 1958, Langley Aeronautical Laboratory, Langley Field, Va.

27/28

A-1

10

10

10

10

-5

-4

-3

-2

10-1

0

80

90

110

120

Takeoff Gross Weight (1000 Lb)

100

130

140

11398 Flights

150

FIGURE A-1. CUMULATIVE PROBABILITY OF TAKEOFF GROSS WEIGHT

Cumulative Probability

10

Cumulative Probability

-3

-2

-1

0

5

10

15

25 Takeoff Fuel Weight (1000 Lb)

20

30

35

11445 Flights

40

FIGURE A-2. CUMULATIVE PROBABILITY OF TAKEOFF

FUEL WEIGHT

10

10

10

10

APPENDIX ADATA PRESENTATION

A-2

-2

10

-1

10

0

80

90

110

Landing Gross Weight (1000 Lb)

100

120

11445 Flights

130

FIGURE A-3. CUMULATIVE PROBABILITY OF LANDING GROSS WEIGHT

Cumulative Probability

10

37.353

8.309

5.286

24.727

Total

0.821

2.149

0.682

0.647

0.498

0.384

0.009

0.07

30-35

0.026

0.052

0.507

0.629

2.665

3.093

1.145

0.14

0.079

25-30

2000-2250

1750-2000

0.017

2.08

11.691

1500-1750

22.709

0.079

3.032

6.317

3.862

0.664

20-25

0.096

0.384

0.009

0.009

9.567

19.056

5.618

15-20

1250-1500

1000-1250

750-1000

0.358

500-750

9.891

12.46

0.367

0-250

10-15

250-500

5-10

11445 Flts

Takeoff Fuel Weight (1000 Lb)

1.232

0.166

0.446

0.323

0.061

0.035

0.192

0.009

35-40

100

0.192

1.319

2.997

1.468

5.513

18.515

17.781

35.526

16.689

Total

FIGURE A-4. CORRELATION OF TAKEOFF FUEL WEIGHT AND FLIGHT DISTANCE, PERCENT OF FLIGHTS

Flight Distance (NM)

Flight Distance (NM)

Takeoff Gross Weight (1000 Lb)

11398 Flts

80-90

90-100

100-110

110-120

120-130

0-250

0.14

2.343

6.413

5.782

2

250-500

0.044

2.676

9.203

13.397

10.177

0.035

500-750

0.132

1.904

5.027

9.589

1.105

0.009

17.766

750-1000

0.079

1.237

3.834

9.037

4.343

0.009

18.538

1000-1250

0.149

0.886

2.062

2.316

0.105

5.519

1250-1500

0.026

0.307

0.404

0.658

0.07

1.465

0.053

0.518

1.5

0.912

2.983

0.035

0.123

0.842

0.316

1.325

0.018

0.088

0.088

0.193

33.927

10.888

1.509

100

1500-1750

1750-2000

0.009

2000-2250

Total

0.184

5.229

18.942

29.321

130-140

140-150

Total

16.678

35.533

FIGURE A-5. CORRELATION OF TAKEOFF GROSS WEIGHT AND FLIGHT DISTANCE, PERCENT OF FLIGHTS

Gross Weight at Touchdown (1000 Lb)

Gross Weight at Liftoff (1000 Lb)

11398 Flts

80-90

90-100

100-110

80-90

0.184

1.193

0.132

4.036

11.046

1.939

0.114

7.765

19.635

4.834

1.044

0.035

33.313

7.747

28.356

9.116

1.43

46.649

0.623

0.728

0.044

1.395

33.927

10.888

1.509

100

90-100

100-110

110-120

110-120

0.184

5.229

18.942

130-140

140-150

Total

1.509

120-130

Total

120-130

29.321

17.135

FIGURE A-6. CORRELATION OF GROSS WEIGHT AT LIFTOFF AND TOUCHDOWN, PERCENT OF FLIGHTS

A-3

Maximum Altitude (1000 Feet)

11723 Flts

0-5

5-10

10-15

15-20

20-25

25-30

30-35

35-40

Total

0-250

0.051

0.563

1.638

2.602

9.068

2.269

0.392

0.136

16.719

0.017

1.689

14.911

10.663

8.249

35.528

500-750

0.068

0.768

8.462

8.436

17.734

750-1000

0.06

0.478

9.733

8.317

18.587

1000-1250

0.034

0.094

3.062

2.32

5.511

1250-1500

0.026

0.631

0.793

1.45

1500-1750

0.026

1.467

1.476

2.969

1750-2000

0.026

0.887

0.384

1.297

0.171

0.034

0.205

35.469

30.146

100

Flight Distance (NM)

250-500

2000-2250 Total

0.051

0.563

1.638

2.619

10.919

18.596

FIGURE A-7. CORRELATION OF MAXIMUM ALTITUDE AND FLIGHT DISTANCE, PERCENT OF FLIGHTS

Altitude Band (Feet)

Total Flight Distance (NM)

11723 Flts

0-250

250-500

500-750

750-1000

1000-1250

1250-1500

1500-1750

1750-2000

2000-2250

2250-2500

29,500-39,500

0.09

20.03

51.4

64.46

70.11

76.33

80.4

81.79

81.63

83.56

19,500-29,500

28.14

42.66

26.6

20.27

17.95

14.44

11.6

11.32

12.54

12.17

9,500-19,500

42.13

22.02

12.76

8.69

6.94

5.67

4.71

3.99

3.44

2.4

4,500-9,500

16.73

8.6

5.26

3.66

2.91

2.05

2.13

1.77

1.25

0.92

1,500-4,500

10.31

5.24

3.09

2.18

1.6

1.19

0.93

0.93

0.89

0.71

500-1,500

2.04

1.07

0.68

0.49

0.34

0.23

0.18

0.17

0.18

0.16

0-500

0.56

0.38

0.21

0.24

0.16

0.08

0.05

0.04

0.06

0.08

Total

100

100

100

100

100

100

100

100

100

100

FIGURE A-8. PERCENT OF TOTAL DISTANCE IN ALTITUDE BANDS

A-4

A-5

Coincident Pressure Altitude (Feet)

0.5

0.6

0.7

0.8

0.9

FIGURE A-9a. COINCIDENT ALTITUDE AT MAXIMUM MACH NUMBER, CRUISE PHASE

Mach Number Mach Number

200

300 Equivalent e (Knots) EquivalentAirspeed, Airspeed,VVe (Knots)

250

V

cruise

350

FIGURE A-9b. COINCIDENT ALTITUDE AT MAXIMUM EQUIVALENT AIRSPEED, CRUISE PHASE

0

0.4

0

0.3

5000

5000

cruise

10000

M

15000

20000

25000

30000

35000

40000

10000

15000

20000

25000

30000

35000

40000

Coincident Pressure Altitude (Feet)

A-6

0

5000

10000

15000

20000

25000

30000

35000

0.3

0.4

0.5 Mach Number Mach Number

0.6

M

0.7

cruise

0.8

FIGURE A-10a. COINCIDENT ALTITUDE AT MAXIMUM MACH NUMBER, ALL FLIGHT PHASES

Coincident Pressure Altitude (Feet)

40000

0.9

0

5000

10000

15000

20000

25000

30000

35000

40000

200

300 EquivalentAirspeed, Airspeed, Ve Ve (Knots) Equivalent (Knots)

250

V

cruise

350

FIGURE A-10b. COINCIDENT ALTITUDE AT MAXIMUM EQUIVALENT AIRSPEED, ALL FLIGHT PHASES

Coincident Pressure Altitude (Feet)

A-7

500

1000

1500

2000

2500

Flight Distance (NM)

0

20

60 Percent Time Autopilot Engaged

40

80

100

FIGURE A-12. CUMULATIVE PROBABILITY OF PERCENT OF FLIGHT TIME ON AUTOPILOT

0

0.1

0.1

0

0.2

0.2

0.4

0.5

0.6

0.7

0.8

0.9

0.3

0

11721 Flights

1

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Great Circle Distance Intergrated Distance

FIGURE A-11. CUMULATIVE PROBABILITY OF FLIGHT DISTANCES

Cumulative Probability

1

Cumulative Probability

A-8

10

10

0

1

2

3

4

-0.4

-2

-1

10

10

10

10

10

-0.3

11723 Flights

-0.2

0

Side Load Factor, ny

-0.1 (g)

0.1

0.2

0.3

0.4

Taxi In Taxi Out

FIGURE A-13. CUMULATIVE FREQUENCY OF MAXIMUM SIDE LOAD FACTOR DURING GROUND TURNS

Cumulative Occurrences per 1000 Flights

-2

-1

0

1

2

3

4

5

-1

1127 1 Flights

-0.5

x

Lo ngitudin al L oad Factor, n (g)

0

0.5

Taxi In Taxi Out

1

FIGURE A-14. CUMULATIVE FREQUENCY OF LONGITUDINAL LOAD FACTOR DURING GROUND TAXI

10

10

10

10

10

10

10

10

A-9

-2

-1

0

1

2

3

-1

1127 1 Fl ights

-0.5

x

Lo ngitudinal L oad Factor, n (g)

0

0.5

With Trus t Reverse rs

With out Thrus t Reverse rs

1

FIGURE A-15. CUMULATIVE FREQUENCY OF LONGITUDINAL LOAD FACTOR DURING LANDING ROLL

10

10

10

10

10

10

0.05

-5

-4

-3

-2

-1

0

0.1

0.15

0.25

0.3

L ongi tudi nal Load Factor, n x (g)

0.2

0.35

0.4

117 18 Fligh ts

0.45

FIGURE A-16. CUMULATIVE PROBABILITY OF MAXIMUM LONGITUDINAL LOAD FACTOR DURING TAKEOFF

10

10

10

10

10

10

A-10

-5

-4

-3

-2

-1

0

-1

-0.8

1172 1 Fl ights

-0.4

Lo ngitudin al L oad Factor, n x (g)

-0.6

-0.2

0

FIGURE A-17. CUMULATIVE PROBABILITY OF MINIMUM LONGITUDINAL LOAD FACTOR DURING LANDING

10

10

10

10

10

10

Cumulative Occurrences per 1000 Flights

-1

0

1

2

3

4

5

-1.5

-1

8679 Flights

0

0.5 Incremental Vertical Load Factor,Δnz (g)

-0.5

1

1.5

Taxi Out Taxi In

FIGURE A-18. CUMULATIVE FREQUENCY OF INCREMENTAL VERTICAL LOAD FACTOR DURING TAXI OPERATIONS

10

10

10

10

10

10

10

A-11

10

0

1

2

3

4

-1

10

10

10

10

10

5

-1.5

-0.5

0

0.5 z

Incremental Vertical Load Factor, Δn

-1 (g)

1

8679 Flights

1.5

FIGURE A-19. CUMULATIVE FREQUENCY OF INCREMENTAL VERTICAL LOAD FACTOR DURING TAKEOFF ROLL

Cumulative Occurrences per 1000 Flights

10

10

0

1

2

3

4

5

-1

10

10

10

10

10

10

-1.5

-1

8679 Flights

0

0.5 Incremental Vertical Load Factor, Δn (g) z

-0.5

1

1.5

w ith Thrust Reverser

w /o Thrust Reverser

FIGURE A-20. CUMULATIVE FREQUENCY OF INCREMENTAL VERTICAL LOAD FACTOR DURING LANDING ROLL

Cumulative Occurrences per 1000 Flights

A-12

0

10

10

10

10

10

-5

-4

-3

-2

-1

10

-1.5

-1

0

0.5 z

Incremental Vertical Load Factor,Δn

-0.5 (g)

1

Maximum Load Factor at Spoiler Deployment Minimum (Rebound) Load Factor at Spoiler Deployment Maximum Load Factor at Touchdown Minimum (Rebound) Load Factor at Touchdown 1.5

FIGURE A-21. CUMULATIVE PROBABILITY OF MINIMUM AND MAXIMUM INCREMENTAL VERTICAL LOAD FACTOR AT TOUCHDOWN AND SPOILER DEPLOYMENT

Cumulative Probability

(g) z

70000

-1

-0.5

0

0.5

1

1.5

80000

100000 110000 120000 130000 140000 Touchdown Gross Weight (Lb)

90000

Maximum Load Factor at Touchdown Minimum (Rebound) Load Factor at Touchdown

FIGURE A-22. COINCIDENT INCREMENTAL VERTICAL LOAD FACTOR AND TOUCHDOWN GROSS WEIGHT

Incremental Vertical Load Factor,Δn

A-13

10

10

10

10

10

-5

-4

-3

-2

-1

0

0

20

40

80

Ground Speed (Knots)

60

100

120

11720 Flights

140

Taxi Out Taxi In

FIGURE A-23. CUMULATIVE PROBABILITY OF GROUND SPEED DURING TAXI

Cumulative Probability

10

10

10

10

10

10

0

-5

-4

-3

-2

-1

10

60

80

11723 Flights

100

120

140 Calibrated Airspeed (Knots)

At Liftoff At Touchdown

160

180

200

FIGURE A-24. CUMULATIVE PROBABILITY OF AIRSPEED AT LIFTOFF AND TOUCHDOWN

Cumulative Probability

A-14

10

10

10

10

10

-5

-4

-3

-2

-1

0

80

100

11723 Flights

140

Calibrated Airspeed (Knots)

120

160

180

FIGURE A-25. CUMULATIVE PROBABILITY OF AIRSPEED AT FLARE

Cumulative Probability

10

10

10

10

10

10

0

-5

-4

-3

-2

-1

10

0

2

4

8

10 Pitch Angle (Degrees)

6

12

14

11723 Flights

Liftoff Touchdown

FIGURE A-26. CUMULATIVE PROBABILITY OF PITCH ANGLE AT LIFTOFF AND TOUCHDOWN

Cumulative Probability

16

A-15

Cumulative Probability

-4

-3

-2

-1

0

0

2

6

8

Pitch Rate (Degrees / Second)

4

10

12

11723 Flights

FIGURE A-27. CUMULATIVE PROBABILITY OF MAXIMUM PITCH RATE AT TAKEOFF ROTATION

10

10

10

10

10

Cumulative Probability

-5

-4

-3

-2

-1

0

-4

-2

0

4

6 Pitch Angle (Degrees)

2

8

10

11723 Flights

12

FIGURE A-28. CUMULATIVE PROBABILITY OF PITCH ANGLE AT TOUCHDOWN PEAK VERTICAL LOAD FACTOR

10

10

10

10

10

10

A-16

Cumulative Occurrences per 1000 Hours

-0.5 0 0.5 Incremental Load Factor, Δnz (g)

1

1.5

-1.5

-2

-1

z

-0.5 0 0.5 Incremental Load Factor, Δn (g)

1

13916 Hours

FIGURE A-30. CUMULATIVE OCCURRENCES OF INCREMENTAL VERTICAL GUST LOAD FACTOR PER 1000 HOURS, COMBINED FLIGHT PHASES

10

0

1

2

3

4

5

6

-1

10

10

10

10

10

10

10

-2

-1

16 0.94 Hrs 233 2.33 Hrs 797 4.72 Hrs 258 2.83 Hrs 86 5.38 Hrs

10

-1.5

Departure, Cl imb, Cruise , Descent, Ap proach,

-1

0

1

2

3

4

5

6

FIGURE A-29. CUMULATIVE OCCURRENCES OF VERTICAL GUST LOAD FACTOR PER 1000 HOURS BY FLIGHT PHASE

10

10

10

10

10

10

10

10

10

Cumulative Occurrences per 1000 Hours

1.5

A-17

Cumulative Occurrences per Nautical Mile

-1.5

-1

0

0.5

Incremental Load Factor, Δn (g) z

-0.5

1

Dep arture , 30,1 56 NM Clim b, 8 81,2 80 NM Cruise , 3,3 90,9 00 NM Des cen t, 9 25,1 40 NM Approa ch, 1 56,9 30 NM

1.5

FIGURE A-31. CUMULATIVE OCCURRENCES OF VERTICAL GUST LOAD FACTOR PER NAUTICAL MILE BY FLIGHT PHASE

10 -7

10 -6

10 -5

10 -4

10 -3

10 -2

10 -1

100

101

10

10

10

10

10

10

10

0

1

-1.5

-7

-6

-5

-4

-3

-2

-1

10

10

-1

z

-0.5 0 0.5 Incremental Load Factor, Δn

(g)

1

5,384,400 NM

1.5

FIGURE A-32. CUMULATIVE OCCURRENCES OF INCREMENTAL VERTICAL GUST LOAD FACTOR PER NAUTICAL MILE, COMBINED FLIGHT PHASES

Cumulative Occurrences per Nautical Mile

A-18

Cumulative Occurrences per Nautical Mile

-6

-5

-4

-3

-2

-1

0

0

10 de

20 30 Derived Gust Velocity, U

B-737 Data NACA TN-4332

Dow nw ard Gusts

(Ft/Sec)

40

8448 Flights 81.07 Hours 12288 NM

10

10

10

10

10

10

0

-6

-5

-4

-3

-2

-1

10

10

1

0

10

de

20 30 Derived Gust Velocity, U

B-737 Data NACA TN-4332

Upw ard Gusts

(Ft/Sec)

40

8448 Flights 81.07 Hours 12288 NM

FIGURE A-33. CUMULATIVE OCCURRENCES OF DERIVED GUST VELOCITY PER NAUTICAL MILE, < 500 FEET

10

10

10

10

10

10

10

10

1

Cumulative Occurrences per Nautical Mile

A-19

10

10

10

10

10

10

0

-6

-5

-4

-3

-2

-1

10

1

0

10 de

30

Derived Gust Velocity, U

20

B-737 Data NACA TN-4332

Dow nw ard Gusts

(Ft/Sec)

40

8448 Flights 207.36 Hours 33241 NM

10

10

10

10

10

10

0

1

-6

-5

-4

-3

-2

-1

10

10

0

10

8448 Flights 207.36 Hours 33241 NM

20 30 40 Derived Gust Velocity, U de (Ft/Sec)

B-737 Data NACA TN-4332

Upw ard Gusts

FIGURE A-34. CUMULATIVE OCCURRENCES OF DERIVED GUST VELOCITY PER NAUTICAL MILE, 500-1,500 FEET

Cumulative Occurrences per Nautical Mile

10

Cumulative Occurrences per Nautical Mile

A-20

10

10

10

10

10

10

0

-6

-5

-4

-3

-2

-1

10

10

0

10 de

30

Derived Gust Velocity, U

20

B-737 Data NACA TN-4332

Dow nw ard Gusts

(Ft/Sec)

40

8448 Flights 775.21 Hours 158034 NM

10

10

10

10

10

10

0

-6

-5

-4

-3

-2

-1

10

10

1

0

10

de

20 30 Derived Gust Velocity, U

B-737 Data NACA TN-4332

Upw ard Gusts

(Ft/Sec)

40

8448 Flights 775.21 Hours 158034 NM

FIGURE A-35. CUMULATIVE OCCURRENCES OF DERIVED GUST VELOCITY PER NAUTICAL MILE, 1,500-4,500 FEET

Cumulative Occurrences per Nautical Mile

1

Cumulative Occurrences per Nautical Mile

A-21

10

10

10

10

10

10

0

-6

-5

-4

-3

-2

-1

10

10

0

10

30

40

8448 Flights 1042.51 Hours 267361 NM

Derived Gust Velocity, U de (Ft/Sec)

20

B-737 Data NACA TN-4332

Dow nw ard Gusts

10

10

10

10

10

10

0

-6

-5

-4

-3

-2

-1

10

10

1

0

10

8448 Flights 1042.51 Hours 267361 NM

20 30 40 Derived Gust Velocity, U de (Ft/Sec)

B-737 Data NACA TN-4332

Upw ard Gusts

FIGURE A-36. CUMULATIVE OCCURRENCES OF DERIVED GUST VELOCITY PER NAUTICAL MILE, 4,500-9,500 FEET

Cumulative Occurrences per Nautical Mile

1

Cumulative Occurrences per Nautical Mile

A-22

10

10

10

10

10

10

0

-6

-5

-4

-3

-2

-1

10

10

0

10

30

40

8448 Flights 1897.14 Hours 658131 NM

Derived Gust Velocity, U de (Ft/Sec)

20

B-737 Data NACA TN-4332

Dow nw ard Gusts

10

10

10

10

10

10

0

-6

-5

-4

-3

-2

-1

10

10

1

0

10

8448 Flights 1897.14 Hours 658131 NM

20 30 40 Derived Gust Velocity, U de (Ft/Sec)

B-737 Data NACA TN-4332

Upw ard Gusts

FIGURE A-37. CUMULATIVE OCCURRENCES OF DERIVED GUST VELOCITY PER NAUTICAL MILE, 9,500-19,500 FEET

Cumulative Occurrences per Nautical Mile

1

Cumulative Occurrences per Nautical Mile

A-23

10

10

10

10

10

10

10

0

-7

-6

-5

-4

-3

-2

-1

10

10

0

10 de

30

Derived Gust Velocity, U

20

B-737 Data NACA TN-4332

Dow nw ard Gusts

(Ft/Sec)

40

8448 Flights 3066.84 Hours 1307330 NM

10

10

10

10

10

10

10

0

-7

-6

-5

-4

-3

-2

-1

10

10

1

0

10

de

20 30 Derived Gust Velocity, U

B-737 Data NACA TN-4332

Upw ard Gusts

(Ft/Sec)

40

8448 Flights 3066.84 Hours 1307330 NM

FIGURE A-38. CUMULATIVE OCCURRENCES OF DERIVED GUST VELOCITY PER NAUTICAL MILE, 19,500-29,500 FEET

Cumulative Occurrences per Nautical Mile

1

Cumulative Occurrences per Nautical Mile

A-24

10

10

10

10

10

10

0

-6

-5

-4

-3

-2

-1

10

10

0

10 de

20 30 Derived Gust Velocity, U

B-737 Data NACA TN-4332

Dow nw ard Gusts

(Ft/Sec)

40

8448 Flights 81.07 Hours 12288 NM

10

10

10

10

10

10

10

0

-7

-6

-5

-4

-3

-2

-1

10

10

1

0

10

de

20 30 Derived Gust Velocity, U

B-737 Data NACA TN-4332

Upw ard Gusts

(Ft/Sec)

40

8448 Flights 6483.36Hours 2808300 NM

FIGURE A-39. CUMULATIVE OCCURRENCES OF DERIVED GUST VELOCITY PER NAUTICAL MILE, 29,500-39,500 FEET

Cumulative Occurrences per Nautical Mile

1

Cumulative Occurrences per Nautical Mile

Cumulative Occurrences per Nautical Mile

10

1

10

0

8448 Flights 992.64 Hours 180678 NM

-1

10

-2

10

-3

10

-4

10

-5

10

FAR 25.345 Limits -6

10

-100

-80

-60

-40

-20

0

20

Derived Gust Velocity, U

40

60

80

100

(Ft/Sec EAS)

de

FIGURE A-40. CUMULATIVE OCCURRENCES OF DERIVED GUST VELOCITY PER

NAUTICAL MILE, FLAPS EXTENDED

10

0

8448 Flights 12560.84 Hours 5064008 NM

-1

Cumulative Occurrences per Nautical Mile

10

-2

10

-3

10

-4

10

-5

10

-6

10

-7

10

FAR 25.341Limits -8

10

-100

-80

-60

-40

-20

0

20

Derived Gust Velocity, U

de

40

60

80

100

(Ft/Sec EAS)

FIGURE A-41. CUMULATIVE OCCURRENCES OF DERIVED GUST VELOCITY PER

NAUTICAL MILE, FLAPS RETRACTED

A-25

10

1

8448 Flights 992.64 Hours 180678 NM

Cumulative Occurrences per Nautical Mile

10

0

10

-1

10

-2

10

-3

10

-4

10

-5

10

-6

-160

-120

-80

-40

0

40

80

120

160

Continuous Gust Intensity, U (Ft/Sec TAS)

σ

FIGURE A-42. CUMULATIVE OCCURRENCES OF CONTINUOUS GUST INTENSITY

PER NAUTICAL MILE, FLAPS EXTENDED

10

0

Cum ulative Occurrences per Nautical Mile

8448 Flights 12560.84 Hours 5064008 NM

10

-1

10

-2

10

-3

10

-4

10

-5

10

-6

10

-7

-160

-120

-80

-40

0

40

80

120

160

Continuous Gust Intensity, U (Ft/Sec TAS)

σ

FIGURE A-43. CUMULATIVE OCCURRENCES OF CONTINUOUS GUST INTENSITY

PER NAUTICAL MILE, FLAPS RETRACTED

A-26

A-27

Cumulative Occurrences per 1000 Hours

2

3

4

5

6

0

0.05

0.1

0.2

z

Incremental Load Factor,Δn

0.15

1.08 Hours

(g)

0.25

0.3

4500-9500 Feet, 0.18 Hours

1500-4500 Feet, 4.14 Hours

500-1500 Feet, 2.75 Hours

<500 Feet,

0.35

FIGURE A-44. CUMULATIVE OCCURRENCES OF INCREMENTAL MANEUVER LOAD FACTOR PER 1000 HOURS DURING DEPARTURE BY ALTITUDE

10

10

10

10

10

Cumulative Occurrences per 1000 Hours

0

0.05

0.1

0.2 z

Incremental Load Factor,Δn

0.15

7.71 Hrs 21.0 Hrs

1,500-4,500 Ft, 4,500-9,500 Ft,

(g)

0.25

0.3

34,500-39,500 Ft, 15.15 Hrs

29,500-34,500 Ft, 42.02 Hrs

24,500-29,500 Ft, 50.11 Hrs

19,500-24,500 Ft, 42.9 Hrs

14,500-19,500 Ft, 33.38 Hrs

9,500-14,500 Ft, 32.49 Hrs

0.029 Hrs

500-1,500 Ft,

FIGURE A-45. CUMULATIVE OCCURRENCES OF INCREMENTAL MANEUVER LOAD FACTOR PER 1000 HOURS DURING CLIMB BY ALTITUDE

1

10

2

10

3

10

4

10

10

5

6

10

0.35

A-28

Cumulative Occurrences per 1000 Hours

0

1

2

3

4

5

6

0

1.33Hrs 9.43 Hrs

1,500-4,500 Ft,

4,500-9,500 Ft,

0.05

0.15

Incremental Load Factor,Δnz (g)

0.1

34,500-39,500 Ft, 285.91 Hrs

29,500-34,500 Ft, 429.61 Hrs

24,500-29,500 Ft, 136.99 Hrs

19,500-24,500 Ft, 49.19 Hrs

14,500-19,500 Ft, 11.16 Hrs

9,500-14,500 Ft, 17.97Hrs

0.0028 Hrs

500-1,500 Ft,

0.2

0.25

FIGURE A-46. CUMULATIVE OCCURRENCES OF INCREMENTAL MANEUVER LOAD FACTOR PER 1000 HOURS DURING CRUISE BY ALTITUDE

10

10

10

10

10

10

10

10

10

10

10

10

10

1

2

3

4

5

6

0

0.05

0.15

0.2

0.25 Incremental Load Factor,Δnz - (g)

0.1

0.3

0.35

500-1,500 Ft, 0.058 Hrs 1,500-4,500 Ft, 8.23 Hrs 4,500-9,500 Ft, 35.3 Hrs 9,500-14,500 Ft, 52.43 Hrs 14,500-19,500 Ft, 39.82 Hrs 19,500-24,500 Ft, 48.13 Hrs 24,500-29,500 Ft, 45.71 Hrs 29,500-34,500 Ft, 25.55 Hrs 34,5000-39,500 Ft, 1.74 Hrs

FIGURE A-47. CUMULATIVE OCCURRENCES OF MANEUVER LOAD FACTOR PER 1000 HOURS DURING DESCENT BY ALTITUDE

Cumulative Occurrences per 1000 Hours

A-29

10

10

10

10

10

1

2

3

4

5

6

0

0.1

0.3

0.4 z

0.5

0.6

14,500-19,500 Ft, 0.0045 Hrs

9,500-14,500 Ft, 0.54 Hrs

4,500-9,500 Ft, 10.35 Hrs

Incremental Load Factor,Δn (g)

0.2

6.65 Hrs

2.46 Hrs

1,500-4,500 Ft, 23.44 Hrs

500-1,500 Ft,

<500 Ft,

0.7

FIGURE A-48. CUMULATIVE OCCURRENCES OF MANEUVER LOAD FACTOR PER 1000 HOURS DURING APPROACH BY ALTITUDE

Cumulative Occurrences per 1000 Hours

10

Cumulative Occurrences per Nautical Mile

0

0.05

0.15

0.2 z

Incremental Load Factor,Δn

0.1

(g)

0.25

0.3

4,500-9,500 Ft, 10935 NM

0.35

199608 NM

500-1,500 Ft,

1,500-4,500 Ft, 27223 NM

82501 NM

<500 Ft,

FIGURE A-49. CUMULATIVE OCCURRENCES OF MANEUVER LOAD FACTOR PER NAUTICAL MILE DURING DEPARTURE BY ALTITUDE

-6

10

-5

10

-4

10

-3

10

-2

10

-1

10

A-30

Cumulative Occurrences per Nautical Mile

0.1

0.15

0.2 z

(g)

0.25

0.3

0.35

Incremental Load Factor,Δn

0

0.05

0.15 Incremental Load Factor,Δnz (g)

0.1

0.2

0.25

500-1,500 Ft, 161 NM 1,500-4,500 Ft, 72324 NM 4,500-9,500 Ft, 471150 NM 9,500-14,500 Ft, 747855 NM 14,500-19,500 Ft, 400115 NM 19,500-24,500 Ft, 1538495 NM 24,500-29,500 Ft, 4070102 NM 29,500-34,500 Ft, 12789833 NM 34,500-39,500 Ft, 8619328 NM

FIGURE A-51. CUMULATIVE OCCURRENCES OF MANEUVER LOAD FACTOR PER NAUTICAL MILE DURING CRUISE BY ALTITUDE

10

10

-7

-5

10

10

-4

10

-3

-2

10

-7

0.05

1650 NM 420019 Nm 1011525 NM 1269761 NM 1141377 NM 1350307 NM 1490689 NM 1253185 NM 457842 NM

-6

0

500-1,500 Ft, 1,500-4,500 Ft, 4,500-9,500 Ft, 9,500-14,500 Ft, 14,500-19,500 Ft, 19,500-24,500 Ft, 24,500-29,500 Ft, 29,500-34,500 Ft, 34,500-39,500 Ft,

-1

10

-6

-5

-4

-3

-2

-1

FIGURE A-50. CUMULATIVE OCCURRENCES OF MANEUVER LOAD FACTOR PER NAUTICAL MILE DURING CLIMB BY ALTITUDE

10

10

10

10

10

10

10

Cumulative Occurrences per Nautical Mile

A-31

Cumulative Occurrences per Nautical Mile

-2

0

0.05

0.15

0.2

Incremental Load Factor,Δnz (g)

0.1

0.25

500-1,500 Ft, 1,500-4,500 Ft, 4,500-9,500 Ft, 9,500-14,500 Ft, 14,500-19,500 Ft, 19,500-24,500 Ft, 24,500-29,500 Ft, 29,500-34,500 Ft, 34,500-39,500 Ft,

0.3

0.35

3189 NM 436033 NM 1715738 NM 2060311 NM 1377681 NM 1522743 NM 1367038 NM 762636 NM 52796 Nm

FIGURE A-52. CUMULATIVE OCCURRENCES OF MANEUVER LOAD FACTOR PER NAUTICAL MILE DURING DESCENT BY ALTITUDE

10

-7

10

-6

-5

10

-4

10

10

-3

10

10

10

10

10

10

-6

-5

-4

-3

-2

0

0.1

0.3

0.4

643585 NM

0.5

0.6

14,500-19,500 Ft, 225 NM

9,500-14,500 Ft, 29830 NM

4,500-9,500 Ft,

Incremental Load Factor,Δnz (g)

0.2

562831 NM

500-1,500 Ft,

1,500-4,500 Ft, 1650915 NM

219647 NM

<500 Ft,

FIGURE A-53. CUMULATIVE OCCURRENCES OF MANEUVER LOAD FACTOR PER NAUTICAL MILE DURING APPROACH BY ALTITUDE

Cumulative Occurrences per Nautical Mile

0.7

A-32

Cumulative Occurrences per 1000 Flight Hours

-1

0

1

2

3

4

5

0

0.1

0.3

0.4 z

0.5

Maneuver Load Factor, Δn

0.2

7974.8 Hours 2582.8 Hours

Cruise, Descent,

(g)

0.6

0.7

Approach, 865.8 Hours

2332.2 Hours

Climb,

Departure, 160.94 Hours

FIGURE A-54. CUMULATIVE OCCURRENCES OF MANEUVER LOAD FACTOR PER 1000 HOURS BY FLIGHT PHASE

10

10

10

10

10

10

10

0.8

10

10

0

1

2

3

4

-2

-1

10

10

10

10

10

0

0.1

0.3

0.4

z

0.5 Maneuver Load Factor, Δn

0.2

(g)

0.6

0.7

13916 Hours

FIGURE A-55. CUMULATIVE OCCURRENCES OF MANEUVER LOAD FACTOR PER 1000 HOURS, COMBINED FLIGHT PHASES

Cumulative Occurrences per 1000 Flight Hours

0.8

A-33

10

10

10

10

10

10

-6

-5

-4

-3

-2

-1

0

0

0.1

0.3

0.4 z

0.5

Maneuver Load Factor, Δn

0.2

3,390,900 NM

Cruise,

(g)

0.6

0.7

Approach, 156,930 NM

Descent, 925,140 NM

881,280 NM

Climb,

Departure, 30,156 NM

FIGURE A-56. CUMULATIVE OCCURRENCES OF MANEUVER LOAD FACTOR PER NAUTICAL MILE BY FLIGHT PHASE

Cumulative Occurrences per Nautical Mile

10

0.8

10

10

10

10

10

10

10

0

-7

-6

-5

-4

-3

-2

-1

10

0

0.1

0.3

0.4

0.5 Maneuver Load Factor, Δn

0.2

z

(g)

0.6

0.7

5,384,400 NM

FIGURE A-57. CUMULATIVE OCCURRENCES OF MANEUVER LOAD FACTOR PER NAUTICAL MILE, COMBINED FLIGHT PHASES

Cumulative Occurrences per Nautical Mile

0.8

A-34

10

0

1

2

3

4

5

-1.5

-1

10

10

10

10

10

10

6

-1

-0.5 0 0.5 Incremental Load Factor, Δnz (g)

1

De part, 16 0.94 Hrs Cli mb, 23 32.2 Hrs Crui se, 79 74.8 Hrs D es cen t, 25 82.8 Hrs Approa ch, 86 5.38 Hrs

1.5

FIGURE A-58. CUMULATIVE OCCURRENCES OF COMBINED MANEUVER AND GUST VERTICAL LOAD FACTOR PER 1000 HOURS BY FLIGHT PHASE

Cumulative Occurrences per 1000 Hours

10

Cumulative Occurrences per 1000 Hours

-1.5

-2

-1

0

1

2

3

4

5

6

-1

z

-0.5 0 0.5 Incremental Load Factor, Δn (g)

1

13916 Hours

1.5

FIGURE A-59. CUMULATIVE OCCURRENCES OF VERTICAL LOAD FACTOR PER 1000 HOURS, COMBINED FLIGHT PHASES

10

10

10

10

10

10

10

10

10

A-35

Cumulative Occurrences per Nautical Mile

-7

-6

-5

-4

-3

-2

-1

0

1

-1.5

-1

0

0.5

Incremental Load Factor, Δn z (g)

-0.5

Depa rt, Cl imb, Cru ise, Descent, App roach,

1

301 56 NM 8812 78 NM 3 3908 57 NM 9251 43 NM 1569 30 NM

1.5

FIGURE A-60. CUMULATIVE OCCURRENCES OF VERTICAL LOAD FACTOR PER NAUTICAL MILE BY FLIGHT PHASE

10

10

10

10

10

10

10

10

10

Cumulative Occurrences per Nautical Mile -7

-6

-5

-4

-3

-2

-1

0

-1.5

-1

0

z

0.5 Incremental Load Factor, Δn

-0.5

(g)

1

5,384,400 NM

1.5

FIGURE A-61. CUMULATIVE OCCURRENCES OF VERTICAL LOAD FACTOR PER NAUTICAL MILE, COMBINED FLIGHT PHASES

10

10

10

10

10

10

10

10

10

6

Cumulative Occurrences per 1000 Hours

19105.01 Hours

10

5

10

4

10

3

10

2

10

1

10

0

10

-1

10

-2

-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

Incremental Load Factor, ny (g)

FIGURE A-62. CUMULATIVE OCCURRENCES OF LATERAL LOAD FACTOR PER 1000 HOURS, COMBINED FLIGHT PHASES

A-36

3

2

Load Factor, nz (g)

1

Velocity (KEAS)

0 0

100

200

300

400

-1

V-n Diagram For Illustration Only -2

FIGURE A-63. COINCIDENT MANEUVER LOAD FACTOR AND SPEED VERSUS V-n DIAGRAM FOR FLAPS RETRACTED

3

1

Load Factor, n

z

(g)

2

Velocity (KEAS)

0 0

100

200

300

400

V-n Diagram For Illustration Only

-1

-2

FIGURE A-64. COINCIDENT MANEUVER LOAD FACTOR AND SPEED VERSUS V-n DIAGRAM FOR FLAPS EXTENDED

A-37

3

Load Factor, nz (g)

2

1

0 0

50

-1

100

150

200

250

300

350

400

Velocity (KEAS)

V-n Diagram For Illustration Only

-2

FIGURE A-65. COINCIDENT GUST LOAD FACTOR AND SPEED VERSUS V-n DIAGRAM FOR FLAPS RETRACTED

2

1.5

1

0.5

Velocity (KEAS)

0 0

50

100

150

200

250

300

350

400

-0.5

V-n Diagram For Illustration Only

-1

-1.5

-2

FIGURE A-66. COINCIDENT GUST LOAD FACTOR AND SPEED VERSUS V-n DIAGRAM FOR FLAPS EXTENDED

A-38

1

Detent 1 Detent 5 Detent 10 Detent 15 Detent 25 Detent 30

Cumulative Probability

0.8

0.6

0.4

0.2

0 120

140

160

180

200

220

240

260

Calibrated Airspeed (Knots)

FIGURE A-67. CUMULATIVE PROBABILITY OF MAXIMUM AIRSPEED IN FLAP

DETENT DURING DEPARTURE

1

Detent 1 Detent 5 Detent 10 Detent 15 Detent 25 Detent 30 Detent 40 Detent 45

Cumulative Probability

0.8

0.6

0.4

0.2

0 120

140

160

180

200

220

240

260

Calibrated Airspeed (Knots)

FIGURE A-68. CUMULATIVE PROBABILITY OF MAXIMUM AIRSPEED IN FLAP

DETENT DURING APPROACH

A-39

100 Percent of Departure Hours (217.6 Hrs) Percent of Total Flight Hours (19105 Hrs)

211.2 Hours

Percent of Time

80

60

40

20 0.6 Hours

0.5 Hours

5.2 Hours

0.1 Hours

0 1

5

10

15

25

30

40

45

Flap Detent

FIGURE A-69. PERCENT OF TIME IN FLAP DETENT DURING DEPARTURE

50 Percent of Approach Hours (1166.9 Hrs) Percent of Total Flight Hours (19105 Hrs) 407.5 Hours

40

Percent of Time

333.1 Hours

30 247.4 Hours

20 155.1 Hours

10 2.8 Hours

3.1 Hours

0.9 Hours

17.1 Hours

0 1

5

10

15

25

30

40

45

Flap Detent

FIGURE A-70. PERCENT OF TIME IN FLAP DETENT DURING APPROACH

A-40

1

Detent 1 Detent 5 Detent 10 Detent 15 Detent 25 Detent 30

Cumulative Probability

0.8

0.6

0.4

0.2

0 50

100

150

200

250

2

Dynamic Pressure, q (Lb/ft )

FIGURE A-71. CUMULATIVE PROBABILITY OF MAXIMUM DYNAMIC PRESSURE IN

FLAP DETENT DURING DEPARTURE

1

Detent 1 Detent 5 Detent 10 Detent 15 Detent 25 Detent 30 Detent 40 Detent 45

Cumulative Probability

0.8

0.6

0.4

0.2

0 0

50

100

150

200

250

Dynamic Pressure, q (Lb/ft2 )

FIGURE A-72. CUMULATIVE PROBABILITY OF MAXIMUM DYNAMIC PRESSURE IN

FLAP DETENT DURING APPROACH

A-41

A-42

10

10

10

10

10

100

-5

-4

-3

-2

-1

0

150

250

300

Equivalent Airspeed (Knots)

200

350

11721 Flights

400

FIGURE A-73. CUMULATIVE PROBABILITY OF MAXIMUM SPEED DURING SPEED BRAKE DEPLOYMENT

Cumulative Probability

10 0

100

-5

10

-4

10

-3

10

-2

10

-1

10

10

150

250

300 Equivalent Airspeed (Knots)

200

350

11721 Flights

400

FIGURE A-74. CUMULATIVE FREQUENCY OF SPEED AT SPEED BRAKE DEPLOYMENT

Cumulative Occurrences per Flight

A-43

0

-1

10

-4

-3

10

-2

10

10

0

5000 Altitude (Feet)

10000 15000 20000 25000 30000 35000 40000

11721 Flights

FIGURE A-75. CUMULATIVE FREQUENCY OF ALTITUDE AT SPEED BRAKE DEPLOYMENT

Cumulative Occurrences per Flight

10

Cumulative Probability

0

10

20

30 Deployment Angle (Degrees)

40

11721 Flights

50

FIGURE A-76. CUMULATIVE PROBABILITY OF MAXIMUM DEPLOYMENT ANGLE DURING SPEED BRAKE DEPLOYMENT, FLAPS RETRACTED

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

A-44

Cumulative Probability

0

0

20

60

Time (Seconds)

40

80

11650 Flights

100

FIGURE A-77. CUMULATIVE PROBABILITY OF TIME WITH THRUST REVERSERS DEPLOYED

10

-5

10

-4

-3

10

10

-2

10

-1

10

10

10

10

10

10

0

-5

-4

-3

-2

-1

10

0

50

100 Ground Speed (Knots)

AT DEPLOYMENT AT STOWAGE 150

11650 Flights

200

FIGURE A-78. CUMULATIVE PROBABILITY OF SPEED AT THRUST REVERSER DEPLOYMENT AND STOWAGE

Cumulative Probability

A-45

Cumulative Probability

-4

-3

-2

-1

0

0

5 Duration (Seconds)

10

15

11650 Flights

20

FIGURE A-79. CUMULATIVE PROBABILITY OF TIME WITH LANDING GEAR EXTENDED AFTER LIFTOFF

10

10

10

10

10

10

10

10

10

10

0

-5

-4

-3

-2

-1

10

0

5

Duration (Minutes)

10

15

11650 Flights

FIGURE A-80. CUMULATIVE PROBABILITY OF TIME WITH LANDING GEAR EXTENDED PRIOR TO TOUCHDOWN

Cumulative Probability

20

A-46

Cumulative Probability

0

-5

-4

-3

-2

-1

140

160

200

220

Calibrated Airspeed (Knots)

180

240

11650 Flights

260

DURING DEPARTURE

DURING APPROACH

FIGURE A-81. CUMULATIVE PROBABILITY OF MAXIMUM AIRSPEED WITH GEAR EXTENDED

10

10

10

10

10

10

-3

10

-2

10

-1

10

0

10

75

80

Percent N1

85

90

95

11650 Flights

100

FIGURE A-82. CUMULATIVE PROBABILITY OF PERCENT OF N1 AT TAKEOFF

Cumulative Probability

Cumulative Probability

1

0.1

11650 Flights

At Take-off At Thrust Reverser Deployment Maximum While Thrust Reverser Deployed 0.01 20

30

40

50

60

70

80

90

Percent N1

FIGURE A-83. CUMULATIVE PROBABILITY OF PERCENT OF N1

A-47/A-48

100

APPENDIX BGREAT CIRCLE DISTANCE CALCULATION

Given: Latitude and Longitude of Departure and Destination Airports Procedure:

ρ = distance from center ϕ = angle from North Pole θ = angle E/W of prime meridian

(see sketch)

The standard mathematical system for spherical coordinates is shown, where three variables specify location: ρ,ϕ, and θ. Let

a = Great Circle Distance in angular measure.

Latitude is measured away from the Equator (0°) to the North Pole (+90°) and the South Pole (-90°); whereas in the standard spherical coordinate system, the North Pole, Equator, and South Pole lie at 0°, 90°, and 180°, respectively. Therefore, ϕ = 90° - latitude transforms latitude readings into equivalent angles (ϕ) in the standard spherical coordinate system. Then b = 90° - LatitudeDep c = 90° - LatitudeDes where b and c are values of ϕ for the departure and destination locations, respectively.

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Longitude is measured away from the prime meridian (0°). Longitudes to the east are positive and to the west negative. However, the standard spherical coordinate system measures its angles in the opposite direction. Therefore, θ = - longitude transforms longitude readings into equivalent angles (θ) in the standard spherical coordinate system. Then A = (- LongitudeDes) - (- LongitudeDep) = LongitudeDep - LongitudeDes where A is the value of θ between the departure and destination locations. The following equation, based on the spherical coordinate system, allows the computation of the Great Circle Distance, a. (Law of cosines for oblique spherical triangles) cos a = cos b cos c + sin b sin c cos A Substituting for b, c, and A from the above equalities, cos a = cos (90° - LatDep) cos (90° - LatDes) + sin (90° - LatDep) sin (90° - LatDes) cos (LonDep - LonDes) Since cos (90° - LatDep) = sin LatDep cos (90° - LatDes) = sin LatDes sin (90° - LatDep) = cos LatDep sin (90° - LatDes) = cos LatDes by replacement one obtains cos a = sin (LatDep) sin (LatDes) + cos (LatDep) cos (LatDes) cos (LonDes - LonDep) Thus a, the angular measure of the great circle arc connecting the departure and destination locations, is obtained as a = cos-1 [sin (LatDep) sin (LatDes) + cos (LatDep) cos (LatDes) cos (LonDes - LonDep)] So, for a expressed in radians 180 deg. 60 min. 1nm 10800a GCD = a radians = nm π radians 1 deg. 1 min. π

and for a expressed in degrees, 60 min. 1 nm GCD = a degrees = 60a nm 1 deg. 1 min.

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Appendix – List of FAA Technical Reports Published in FY98

Report Number

Title

R&D Highlights 1998

Highlights of the major accomplishments and applications.

DOT/FAA/AR-TN97/50

Comparison of Radial and Bias-Ply Tire Heating on a B-727 Aircraft

DOT/FAA/AR-97/99

Fire-Resistant Materials: Research Overview

DOT/FAA/AR-95/18

User’s Manual for the FAA Research and Development Electromagnetic Database (FRED)

DOT/FAA/AR-97/7

Advanced Pavement Design: Finite Element Modeling for Rigid Pavement Joints, Report II: Model Development

DOT/FAA/AR-97/26

Impact of New Large Aircraft on Airport Design

DOT/FAA/AR-97/64

Operational Evaluation of a Health and Usage Monitoring Systems (HUMS)

DOT/FAA/AR-TN98/15

Fire Testing of Ethanol-Based Hand Cleaner

DOT/FAA/AR-95/111

Stress-Intensity Factors for Elliptical Cracks Emanating from Countersunk Rivet Holes

DOT/FAA/AR-97/9

An Acoustic Emission Test for Aircraft Halon 1301 Fire Extinguisher Bottles

DOT/FAA/AR-97/37

Development of an Improved Magneto-Optic/Eddy-Current Imager

DOT/FAA/AR-97/69

Automated Inspection of Aircraft

DOT/FAA/AR-97/5

Marginal Aggregates in Flexible Pavements: Field Evaluation

DOT/FAA/AR-97/87

A Predictive Methodology for Delamination Growth in Laminated Composites, Part I: Theoretical Development and Preliminary Experimental Results

DOT/FAA/AR-TN97/103

Initial Development of an Exploding Aerosol Can Simulator

DOT/FAA/AR-97/56

Applications of Fracture Mechanics to the Durability of Bonded Composite Joints

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Report Number

Title

DOT/FAA/AR-96/97

Stress-Intensity Factors Along Three-Dimensional Elliptical Crack Fronts

DOT/FAA/AR96/119

Vertical Drop Test of a Beechcraft 1900C Airliner

DOT/FAA/AR-98/22

FAA T53-L-13L Turbine Fragment Containment Test

DOT/FAA/AR-97/85

Response and Failure of Composite Plates with a Bolt-Filled Hole

DOT/FAA/AR-98/26

A Review of the Flammability Hazard of Jet A Fuel Vapor in Civil Transport Aircraft Fuel Tanks

DOT/FAA/AR-TN97/108

Effects of Concentrated Hydrochloric Acid Spills on Aircraft Aluminum Skin

DOT/FAA/AR-TN98/32

Cargo Compartment Fire Protection in Large Commercial Transport Aircraft

DOT/FAA/AR-98/28

Statistical Loads Data for Boeing 737-400 Aircraft in Commercial Operations

DOT/FAA/AR-97/47

Development of Advanced Computational Models for Airport Pavement Design

DOT/FAA/AR-98/34

Health Hazards of Combustion Products From Aircraft Composite Materials

DOT/FAA/AR-97/81

Bioremediation of Aircraft Deicing Fluids (Glycol) at Airports

DOT/FAA/AR-TN97/8

Heats of Combustion of High-Temperature Polymers

DOT/FAA/AR-95/29

Fiber Composite Analysis and Design: Composite Materials and Laminates, Volume I

FACT SHEETS

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