DOT/FAA/AR-05/7 

Office of Aviation Research 

Washington, D.C. 20591

Study of Side Load Factor During 

Aircraft Ground Operations 

March 2005 

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. This 

document does not constitute FAA certification policy. Consult your local 

FAA aircraft certification office as to its use. 

This report is available at the Federal Aviation Administration William J.

Hughes Technical Center's Full-Text Technical Reports page:

actlibrary.tc.faa.gov in Adobe Acrobat portable document format (PDF). 
Technical Report Documentation Page 

1. Report No. 

DOT/FAA/AR-05/7 

2. Government Accession No. 3. Recipient's Catalog No. 

5. Report Date 

March 2005 

4. Title and Subtitle 

STUDY OF SIDE LOAD FACTOR DURING AIRCRAFT GROUND 

OPERATIONS 6. Performing Organization Code 

7. Author(s) 

Todd Jones, John W. Rustenburg, Donald A. Skinn, and Daniel O. Tipps 

8. Performing Organization Report No. 

UDR-TR-2004-00076 

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 

11. Contract or Grant No. 

Grant No.: 2001-G-005 

13. Type of Report and Period Covered 

Technical Report 

12. Sponsoring Agency Name and Address 

U.S. Department of Transportation 

Federal Aviation Administration 

Office of Aviation Research 

Washington, DC 20591 

14. Sponsoring Agency Code 

ANM-110 

15. Supplementary Notes 

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

The primary objective of this study was to support the Federal Aviation Administration (FAA) Operational Loads Monitoring 

Research Program by developing new and improved methods and criteria for processing and presenting commercial transport 

airplane ground loads usage data. The scope of activities performed involved (1) defining the service-related factors that 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) reducing, analyzing, and providing processed data in statistical 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 that influence the structural integrity of commercial 

transport aircraft. 

The data presented in this report will provide the user with information comparing the side load factors encountered during ground 

maneuvers for airplane models B-747-400, B-767-200, B-737-400, CRJ100, and A320 in actual operational usage. The University 

of Dayton Research Institute database used for this report consisted of 95,862 flight hours for the B-747-400; 44,990 flight hours 

for the B-767-200; 89,269 flight hours for the B-737-400; 463 flight hours for the CRJ100; and 30,817 flight hours for the A320. 

17. Key Words 

Side/Lateral load factor, B-747-400, B-767-200, B-737-400, 

CRJ100, A320, Ground loads, Operational data, Statistical 

loads data, Taxi-out, Taxi-in, Takeoff and Landing roll, 

Touchdown event, Runway turnoff 

18. Distribution Statement 

This document is available to the public through the National 

Technical Information Service (NTIS), Springfield, Virginia 

22161.

19. Security Classif. (of this report) 

Unclassified 

20. Security Classif. (of this page) 

Unclassified 

21. No. of Pages 

49 

22. Price 

N/A 

Form DOT F1700.7 (8-72) Reproduction of completed page authorized 
PREFACE 

The Flight Systems Integrity Group of the Structural Integrity Division at the University of

Dayton Research Institute performed this work under Federal Aviation Administration (FAA) 

Grant No. 2001-G-005 entitled “Assessment of Actual Operational Usage on Large Wide Body 

Transport Aircraft.” 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. John Howford FAA Chief Scientific and Technical Advisor 

for Loads/Aeroelasticity. Mr. Daniel Tipps was the principal investigator for the University of 

Dayton and provided overall technical direction for this effort. Mr. Donald Skinn developed the 

data reduction algorithms, programmed the data reduction criteria, and performed the data 

reduction. Mr. John Rustenburg along with Mr. Todd Jones performed the data analysis, created 

the graphical presentations, and assisted in preparation of the final report. 

iii/iv
TABLE OF CONTENTS 

Page 

EXECUTIVE SUMMARY vii 

1. INTRODUCTION 1 

2. DATA REDUCTION CRITERIA 1 

2.1 Touchdown Criteria Defined 1 

2.2 New Touchdown Criteria Development 2 

2.2.1 Radio Altitude Method 3 

2.2.2 Pitch Angle Method 4 

2.3 Ground Phases Defined 7 

2.3.1 Taxi-Out and Taxi-In 9 

2.3.2 Takeoff and Landing Roll 9 

2.3.3 Runway Turnoff 9 

3. DATA PRESENTATION 10 

4. CONCLUSIONS 13 

APPENDIX A—COMPARATIVE SIDE LOAD FACTOR DATA

v
LIST OF FIGURES

Figure Page 

1 B-747-400 Cumulative Ny Occurrences Found Using Original Ground Phase Criteria 2 

2 B-747 Radio Altitude Method Error 3

3 A320 Radio Altitude Method Error 4

4 Time History Illustrating Pitch Angle Method 5

5 B-747 Pitch Angle, Nose Gear Squat Comparison for 250 Flights 6

6 A320 Pitch Angle, Nose Gear Squat Comparison for 256 Flights 6

7 CRJ100 Pitch Angle, Nose Gear Squat Comparison for 359 Flights 7 

8 Ground Phase Schematic 8

LIST OF TABLES 

Table Page 

1 Flight Phase Criteria 8

2 Flight Statistics 10

3 Statistical Data Formats 10

4 Design Weight Values Used for Ny Correction 13

vi
EXECUTIVE SUMMARY

The primary objective of this study was to support the Federal Aviation Administration (FAA) 

Operational Loads Monitoring Research Program by developing new and improved methods and 

criteria for processing and presenting commercial transport airplane ground loads usage data. 

The scope of activities performed involved (1) defining the service-related factors that 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) reducing, 

analyzing, and providing processed data in statistical 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 

that influence the structural integrity of commercial transport aircraft. 

The data presented in this report will provide the user with information comparing the side load

factors encountered during ground maneuvers for the B-747-400, B-767-200, B-737-400, 

CRJ100, and A320 in actual operational usage. The University of Dayton Research Institute 

database consisted of 95,862 flight hours for airplane models B-747-400; 44,990 flight hours for 

the B-767-200; 89,269 flight hours for the B-737-400; 463 flight hours for the CRJ100; and 

30,817 flight hours for the A320. 

vii/viii
1. INTRODUCTION. 

Lateral acceleration certification criteria outlined by Title 14 Code of Federal Regulations (CFR) 

for commercial aircraft ground operations are based primarily on two ground events that are 

considered to be the most critical to the aircraft structure; those events being the touchdown 

event (14 CFR 25.485) and turning (14 CFR 25.495). Data reduced using previously accepted

methods of ground phase breakdown showed that for the B-747-400 aircraft, the largest 

magnitudes of lateral accelerations occurred during the landing roll phase. Since there was no 14

CFR criteria specified for side load spectrum during this phase of ground maneuver, additional 

investigation ensued about possible causes. Further examination into the high Ny values that

appeared in the landing roll revealed that the occurrences were taking place within seconds after 

main gear touchdown. Discussion of this fact with experienced flight loads professionals 

resulted in the proposal that the current touchdown phase criteria did not capture the landing 

event completely and should be re-evaluated. 

The decision was made to extend the touchdown event to include the time period through nose 

gear touchdown. At the request of the Federal Aviation Administration (FAA), the University of

Dayton Research Institute (UDRI) developed new criteria for the touchdown event and also 

performed data reduction for ground phases on a selection of available aircraft. The FAA, along 

with the Aviation Rulemaking Advisory Committee, displayed interest in additional criteria for 

14 CFR 25.495, turning. The concern was that the current CFR’s turning criterion was too 

stringent and could be lowered in special cases. Regulatory authorities in position to make

special conditions to 14 CFR 25.495 were hesitant to do so without the appropriate technical 

substantiation. Initially, only the ground maneuver data generated for the B-747-400 had been 

updated; however, similar data was requested for additional aircraft within the UDRI database 

(B-737-400, B-767-200, A320, and CRJ100) for comparison purposes. 

2. DATA REDUCTION CRITERIA. 

The following section explains the criterion to identify the touchdown event that was used in 

previous reports and then describes the procedure involved in updating this criteria. After the

description of the development of the new touchdown event, phase descriptions for the 

remaining ground maneuvers are given. 

2.1 TOUCHDOWN CRITERIA DEFINED.

The criteria for reporting lateral acceleration (Ny) occurring in the touchdown event was 

previously 3 seconds prior to main gear squat closure until 1 second after main gear squat. 

Figure 1 shows the results produced with this original criteria. The maximum Ny values were 

observed to occur in the landing roll phase. 

The main objective for redefining the touchdown criteria was to ensure that Ny occurrences

associated with the landing event are grouped with the landing event and not grouped in the 

landing roll. In order to do this, the touchdown event was redefined to include the time period 

through closure of the nose gear squat switch. This was accomplished by changing the 

touchdown event criteria to start 3 seconds prior to main gear squat and end 1 second after nose 

gear squat. The updated criteria would increase the time and also the occurrences of Ny 

1 
measured during the touchdown event, therefore reducing the time Ny is measured in the new 

shortened landing roll. This was acceptable because it was important to group Ny events related 

to landing within the touchdown event and not in the landing roll phase. 

10-5

10-4

10-3

10-2

10-1

100

101

102

103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi-out

Takeoff Roll

Touchdown

Landing Roll

Turnoff

Taxi-in

Combined

Cumulative Occurrences

p

er Flight

Lateral Load Factor Ny, (g)

B747-400

95862.9 Flight hours

11064 Flights

FIGURE 1. B-747-400 CUMULATIVE Ny OCCURRENCES FOUND USING ORIGINAL 

GROUND PHASE CRITERIA 

2.2 NEW TOUCHDOWN CRITERIA DEVELOPMENT. 

The new criteria for defining the landing event could simply be applied to the three aircraft in the

database on which the nose gear squat switch parameter was available (B-747-400, A320, and 

CRJ100). The remaining two aircraft being evaluated for this study (B-767-200 and B-737-400) 

2 
did not have the nose gear squat indicator data recorded and, therefore, required an alternative

method of identifying when the nose gear was down. A detailed analysis of the data from the

three aircraft models, which had nose squat indications, was conducted to determine a consistent

method that would accurately estimate when the nose gear was down for those models without 

nose squat indications. The primary candidate parameters for this supplemental nose gear study 

were radio altitude and pitch angle. 

2.2.1 Radio Altitude Method. 

The method using radio altitude involved calculating the average altitude for each flight between 

15 and 30 seconds after touchdown. The average altitude would serve as the reference that the

aircraft was down, then assuming the nose touched down when the aircraft crossed that average. 

Figure 2 shows that for the B-747, the method performed well using this approximation when

compared to the nose gear squat indicator. However, the same method applied to the A320 

resulted in misidentifying nose gear squat indicator early (figure 3). The radio altitude procedure 

was ruled out when the results between the B-747-400 and the A320 for identifying nose gear 

down were not comparable. The discrepancy with the radio altitude method was likely due to 

the difference in location of the flight recorder within the airplanes. 

FIGURE 2. B-747 RADIO ALTITUDE METHOD ERROR 

3 
FIGURE 3. A320 RADIO ALTITUDE METHOD ERROR 

2.2.2 Pitch Angle Method. 

The method for determining when the nose gear was down using pitch angle was applied 

identically between the three aircraft used in the study (B-747-400, A320, and CRJ100). The 

pitch angle method, similar to the radio altitude procedure, consisted of calculating the average 

pitch angle of each flight between 15 and 30 seconds after main gear squat. This average was 

used as the initial reference line and identified when the aircraft was flat on the runway, i.e., 

constant pitch angle. The original reference line was then shifted half of a degree to make sure 

that the criteria would identify when the nose gear was down for every flight. When the

aircraft’s pitch angle first crossed the reference line (average pitch angle on the runway plus the 

half a degree), the nose gear was assumed to be down and the touchdown event concluded 

(figure 4). As figure 4 shows, the pitch angle method ensures that the nose squat is included 

within the landing event.

4 
-1

-0.5

0

0.5

1

1.5

2

3584 3588 3592 3596 3600 3604 3608

Pitch Angle

Average Pitch Angle 15-30 sec After Main Squat (-0.39344)

Avergage Pitch Angle + 0.5 degrees (0.10656)

Pit

c

h Angle (degrees)

Time (seconds)

Nos

e Squ

at

A320

E

vent Concluded

FIGURE 4. TIME HISTORY ILLUSTRATING PITCH ANGLE METHOD 

Cumulative occurrences of Ny values measured in the touchdown event using the pitch angle 

method were checked against Ny occurrences found using the criteria of identifying the end of

touchdown that uses nose squat plus a second. Figures 5 and 6 show the favorable results found 

between the two methods for the B-747-400 and the A320 airplanes. Figure 7 contains the 

results for the CRJ100. The CRJ100 in previous research was identified to land with lower pitch 

angles than the other aircraft in the study, with some flat landings (main and nose touching down 

simultaneously) occurring in the sample data set. This resulted in high Ny values being recorded

in both the landing event and the landing roll. The positive results from the B-747-400, A320, 

and the explanation for inconsistency in the CRJ100 data confirmed that the pitch angle method 

would ensure that the nose gear down condition was included in the touchdown event with

minimal affect on the landing roll. 

5 
100

101102103104105

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35

B747

Nose Gear, TDPitch Angle, TDNose Gear to TurnoffPitch Angle to Turnoff

s ce en rrucc O ve tia muluC

Ny (g)

100101102103104105

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35

A320

Nose Gear, TDPitch Angle, TDNose Gear to TurnoffPitch Angle to Turnoff

s ce en rrucc O ve tia muluC

Ny (g)

6

FIGURE 5. B-747 PITCH ANGLE, NOSE GEAR SQUAT 

COMPARISON FOR 250 FLIGHTS

FIGURE 6. A320 PITCH ANGLE, NOSE GEAR SQUAT 

COMPARISON FOR 256 FLIGHTS
100

101

102

103

104

0 0.05 0.1 0.15 0.2 0.25

CRJ

Nose Gear, TD

Pitch Angle, TD

Nose Gear to Turnoff

Pitch Angle to Turnoff

Cu

mulative Occurrences

Ny (g)

FIGURE 7. CRJ100 PITCH ANGLE, NOSE GEAR SQUAT COMPARISON 

FOR 359 FLIGHTS 

2.3 GROUND PHASES DEFINED. 

UDRI separated the ground portion of each flight from the time it departed the gate area to its 

return to the gate into phases called taxi-out, takeoff roll, touchdown event, landing roll, runway 

turnoff, and taxi-in. Specific data reduction criteria were developed by UDRI and used to 

identify the beginning and end of each of these phases. Figure 8 shows these phases and events. 

7 
Runway

Turnoff

TAXIWAY

TAXI OUT TAXI IN

Touchdown

Event LANDING ROLL

GATE

T/R D T/R Stowed eployed

Liftoff

RUNWAY

Runway

Turnoff

TAXIWAY

TAXI OUT TAXI IN

Touchdown

Event LANDING ROLL

GATE

T/R D T/R Stowed eployed

Liftoff

RUNWAY

TAKEOFF ROLL

FIGURE 8. GROUND PHASE SCHEMATIC 

The criteria used to define each of these phases are summarized in table 1 and discussed in more 

detail in the following paragraphs. 

TABLE 1. FLIGHT PHASE CRITERIA 

Phase/Event Defining Conditions

Taxi-Out From engine start to beginning of takeoff roll 

Takeoff Roll Ground acceleration > 2kts/sec for at least 20 seconds beginning 

with the time slice where the first ground speed rate change 

greater than 2 kts/sec for that sequence occurred

Touchdown Event From 3 seconds prior to main gear squat switch on until 1 second 

after nose gear squat (or pitch angle method) 

Landing Roll Begins immediately following touchdown event and ends at the 

start of runway turnoff 

Runway Turnoff From first sequential magnetic heading change >2 degrees in the 

same direction from runway heading and subsequent heading 

changes >13.5 degrees 

Taxi-In After runway turnoff to gate or recorder shutdown 

8 
2.3.1 Taxi-Out and Taxi-In. 

UDRI defined all aircraft movement from engine start-up until the aircraft begins its takeoff roll 

as being taxi-out. Taxi-in was defined as beginning from the point where the aircraft completed 

its turnoff from the active runway after its landing roll to when the aircraft was parked at the gate 

or the recorder was shutdown. 

2.3.2 Takeoff and Landing Roll. 

UDRI identified the beginning of the takeoff roll by searching for ground speeds that accelerated 

at rates greater than 2 kts/sec for a minimum duration of 20 seconds. Then, when these values 

were found, the beginning of the takeoff roll was assigned as being the time slice where the first 

ground speed rate change greater than 2 kts/sec for that sequence occurred. The takeoff roll ends 

at liftoff with the squat switch off signal. 

The landing roll phase was defined as beginning immediately after the touchdown event and 

ending when the aircraft starts its turnoff from the active runway. 

2.3.3 Runway Turnoff. 

UDRI used changes in magnetic heading to identify the beginning and the end of the aircraft’s 

turnoff from the active runway. After the aircraft touched down and was on the ground for four

seconds, the subsequent average magnetic heading readings were used to define the aircraft’s 

landing centerline. UDRI then searched for magnetic heading changes that continuously moved 

in the same direction away from this centerline. When the aircraft’s sequential magnetic heading 

change exceeded 13.5 degrees from the direction of the landing centerline or the integrated 

distance from the centerline exceeded 100 feet, the time slice associated with the first sequential 

heading change greater than 2 degrees from the landing centerline in the direction of the turn was 

defined as the beginning of the airplane’s turnoff from the runway. 

UDRI developed the 100-foot deviation as an alternate method of identifying flights involving 

shallow turns from the runway that did not exceed the 13.5 degree turn criteria. This method 

used aircraft ground speed and magnetic heading to calculate the aircraft’s position relative to the 

runway centerline. Then, as above, the time slice associated with the first aircraft movement 

away from the landing centerline in the direction of the turn was defined as the beginning of the 

aircraft’s turnoff from the runway. 

The end point of this turnoff from the runway was also identified using magnetic heading 

readings. UDRI developed an algorithm that used the changes in magnetic heading, while the

aircraft was in its turn, to identify when the aircraft had either returned to taxiing in a straight 

line or was turning in the opposite direction. The first point that provided this indication was 

then defined as the end point of the turnoff from the runway. This point is also the beginning of 

the taxi-in phase. 

9 
3. DATA PRESENTATION. 

The statistical data presented in this section provided the FAA and aircraft manufacturers with 

the information that was needed to assess the side load factors for each of the defined ground 

phases for the B-747-400, B-767-200, B-737-400, CRJ100, and A320. Table 2 reports the 

amount of flight hours, total number of flights, and the average flight length for each of the five 

aircraft used in this study. All data were checked, and any suspicious flights were analyzed and 

removed if the data were found to be faulty. 

TABLE 2. FLIGHT STATISTICS 

Aircraft Flights Flight Hours

Average Flight Time

(Hours) 

B-747-400 11,064 95,862 8.66

B-767-200 6,551 44,990 6.87

B-737-400 60,734 89,269 1.47

CRJ100 359 463 1.29

A320 10,066 30,817 3.06

Table 3 lists the statistical formats for which the data were processed. The side load factor data 

formats are grouped together within the table in an attempt to categorize the results by aircraft

model and by individual ground phases. 

TABLE 3. STATISTICAL DATA FORMATS 

Data Description Figure 

LATERAL LOAD FACTOR BY AIRCRAFT MODEL 

B-747-400

Cumulative Occurrences of Lateral Load Factor per Flight by Ground Phase A-1 

Cumulative Occurrences of Lateral Load Factor per Flight Hour by Ground Phase A-2

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight by Ground Phase A-3 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight Hour by Ground Phase A-4 

Summary Cumulative Occurrences of Lateral Load Factor per Flight by Ground Phase A-5 

Summary Cumulative Occurrences of Lateral Load Factor per Flight Hour by Ground Phase A-6 

B-767-200

Cumulative Occurrences of Lateral Load Factor per Flight by Ground Phase A-7 

Cumulative Occurrences of Lateral Load Factor per Flight Hour by Ground Phase A-8

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight by Ground Phase A-9 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight Hour by Ground Phase A-10 

Summary Cumulative Occurrences of Lateral Load Factor per Flight by Ground Phase A-11 

Summary Cumulative Occurrences of Lateral Load Factor per Flight Hour by Ground Phase A-12 

10 
TABLE 3. STATISTICAL DATA FORMATS (Continued) 

Data Description Figure 

LATERAL LOAD FACTOR BY AIRCRAFT MODEL (continued) 

B-737-400

Cumulative Occurrences of Lateral Load Factor per Flight by Ground Phase A-13 

Cumulative Occurrences of Lateral Load Factor per Flight Hour by Ground Phase A-14

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight by Ground Phase A-15 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight Hour by Ground

Phase 

A-16 

Summary Cumulative Occurrences of Lateral Load Factor per Flight by Ground Phase A-17 

Summary Cumulative Occurrences of Lateral Load Factor per Flight Hour by Ground Phase A-18 

CRJ100 

Cumulative Occurrences of Lateral Load Factor per Flight by Ground Phase A-19 

Cumulative Occurrences of Lateral Load Factor per Flight Hour by Ground Phase A-20

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight by Ground Phase A-21 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight Hour by Ground

Phase 

A-22 

Summary Cumulative Occurrences of Lateral Load Factor per Flight by Ground Phase A-23 

Summary Cumulative Occurrences of Lateral Load Factor per Flight Hour by Ground Phase A-24 

A320

Cumulative Occurrences of Lateral Load Factor per Flight by Ground Phase A-25 

Cumulative Occurrences of Lateral Load Factor per Flight Hour by Ground Phase A-26

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight by Ground Phase A-27 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight Hour by Ground

Phase 

A-28 

Summary Cumulative Occurrences of Lateral Load Factor per Flight by Ground Phase A-29 

Summary Cumulative Occurrences of Lateral Load Factor per Flight Hour by Ground Phase A-30 

LATERAL LOAD FACTOR BY GROUND PHASES

TAXI-OUT 

Cumulative Occurrences of Lateral Load Factor per Flight During Taxi-Out by Aircraft Model A-31 

Cumulative Occurrences of Lateral Load Factor per Flight Hour During Taxi-Out by Aircraft Model A-32 

TAKEOFF ROLL 

Cumulative Occurrences of Lateral Load Factor per Flight During Takeoff by Aircraft Model A-33 

Cumulative Occurrences of Lateral Load Factor per Flight Hour During Takeoff by Aircraft Model A-34 

TOUCHDOWN 

Cumulative Occurrences of Lateral Load Factor per Flight During Touchdown by Aircraft Model A-35 

Cumulative Occurrences of Lateral Load Factor per Flight Hour During Touchdown by Aircraft Model A-36 

LANDING ROLL 

Cumulative Occurrences of Lateral Load Factor per Flight During Landing Roll by Aircraft Model A-37 

Cumulative Occurrences of Lateral Load Factor per Flight Hour During Landing Roll by Aircraft Model A-38 

11 
TABLE 3. STATISTICAL DATA FORMATS (Continued) 

Data Description Figure 

LATERAL LOAD FACTOR BY GROUND PHASES (Continued)

RUNWAY TURNOFF 

Cumulative Occurrences of Lateral Load Factor per Flight During Runway Turnoff by Aircraft Model A-39 

Cumulative Occurrences of Lateral Load Factor per Flight Hour During Runway Turnoff by Aircraft

Model

A-40 

TAXI-IN

Cumulative Occurrences of Lateral Load Factor per Flight During Taxi-In by Aircraft Model A-41 

Cumulative Occurrences of Lateral Load Factor per Flight Hour During Taxi-In by Aircraft Model A-42 

CORRECTED LATERAL LOAD FACTOR BY GROUND PHASES 

TAXI-OUT 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight During Taxi-Out by

Aircraft Model

A-43 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight Hour During TaxiOut by Aircraft ModelA-44 

TAKEOFF ROLL 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight During Takeoff Roll

by Aircraft Model 

A-45 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight Hour During

Takeoff Roll by Aircraft Model 

A-46 

TOUCHDOWN 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight During Touchdown 

by Aircraft Model 

A-47 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight Hour During

Touchdown by Aircraft Model

A-48 

LANDING ROLL 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight During Landing Roll

by Aircraft Model 

A-49 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight Hour During

Landing Roll by Aircraft Model 

A-50 

RUNWAY TURNOFF 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight During Runway

Turnoff by Aircraft Model

A-51 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight Hour During

Runway Turnoff by Aircraft Model 

A-52 

TAXI-IN

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight During Taxi-In by

Aircraft Model

A-53 

Cumulative Occurrences of (Recorded Weight/Max Landing Weight)*Ny per Flight Hour During Taxi-In 

by Aircraft Model 

A-54 

Figures A-1 through A-54 are presented in appendix A. It should also be noted that the data 

presented in these figures were checked and any data found to be erroneous was removed. 

Cumulative occurrence of lateral load factor plots provided in appendix A present data in two 

forms, by flight and by flight hours. The values of Ny presented are the absolute value with no 

12 
differentiation between left and right turns. These plots provide ground phase data grouped by 

aircraft model. Additionally, the data is provided for each ground phase separately for 

comparison between different aircraft models. 

Data contained in the plots that are identified as corrected have Ny values that were adjusted to

take into account weight loss that occurs in flight when fuel mass is burned off. Lateral load 

factors reported in these plots have been multiplied by the corresponding gross weight at 

touchdown and then divided by the maximum ramp or landing weight as appropriate for that

aircraft model. Gross weight was not available for the CRJ100 model, so the corrected data in 

these plots were multiplied by the maximum landing weight and, again, divided by the maximum 

ramp weight. Table 4 provides the numerical values of maximum landing and ramp weights

used by each model. 

TABLE 4. DESIGN WEIGHT VALUES USED FOR Ny CORRECTION 

B-747-400

(lb) 

B-767-200 

(lb) 

B-737-400

(lb) 

A320 

(lb) 

CRJ100

(lb) 

Maximum Ramp Weight 877,000 352,200 143,000 162,920 53,250 

Maximum Landing Weight 652,000 278,000 121,000 142,195 47,000 

The takeoff roll phase for the CRJ100 contained some high Ny values. Closer examination as to 

why shows that the CRJ100, because of its small size, is capable of quickly accelerating around 

the turn from the taxiway to the runway for takeoff. As a result, instead of the Ny appearing in 

the taxi-out phase as it should, the plane has met the criteria for takeoff roll based on its 

acceleration, even though it is still turning onto the runway. 

4. CONCLUSIONS. 

In support of a number of Federal Aviation Administration certification initiatives and Aviation 

Rulemaking Advisory Committee activities, data formats for ground phase operations that were 

not previously available have been included in this report. The updated ground phase criteria 

and the large quantity of flight data within this report make it a very complete resource for 

characterizing aircraft lateral load factor during ground operations. The data herein has been

presented in a manner that allows for individual aircraft to be studied (plots by model) as well in

a way that allows comparisons among different aircraft models to be made (plots by phase). 

The figures in appendix A shows that, in general, the size of the aircraft does appear to be a 

significant factor of not only when high Ny values occur, but also the magnitude of Ny. Small

aircraft such as the CRJ100 and B-737, for example, tend to see most of their higher Ny 

occurrences while turning (due to higher speeds and gear layout). Larger aircraft are prone to 

encounter lower values of Ny taxiing and tend to have their highest Ny occurrences found during 

the touchdown event and rollout. 

As data for future aircraft models or increased flight hours for existing models become available, 

these same formats will be created and provided either in future flight load reports or in a manner 

similar to this report. 

13/14
APPENDIX A—COMPARITIVE SIDE LOAD FACTOR DATA

A-1
10-6

10-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out Takeoff rollLanding rollTurn off Taxi inCombined

thgilFrepsecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

B747-40095862.9 Flight hours11064 Flights

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi outTakeoff rollLanding rollTurn off Taxi inCombined

uroHrepsecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

B747-40095862.9 Flight hours11064 Flights

A-2

FIGURE A-1. CUMULATIVE OCCURRENCES OF LATERAL 

LOAD FACTOR PER FLIGHT BY 

GROUND PHASE (B-747-400) 

FIGURE A-2. CUMULATIVE OCCURRENCES OF LATERAL 

LOAD FACTOR PER FLIGHT HOUR BY 

GROUND PHASE (B-747-400) 
A-3

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out corrected Takeoff roll correctedLanding roll correctedTurn off correctedTaxi in corrected Combined corrected

htgil Fr pe s ce enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

B747-40095862.9 Flight hours11064 Flights

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out correctedTakeoff roll correctedLanding roll correctedTurn off correctedTaxi in corrected Combined corrected

ruo Hr pe ces enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

B747-40095862.9 Flight hours11064 Flights

FIGURE A-3. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT BY 

GROUND PHASE (B-747-400) 

FIGURE A-4. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT HOUR BY 

GROUND PHASE (B-747-400) 
10-6

10-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

CombinedCombined correctedTouchdownTouchdown corrected

htgi Fl r pes ce enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

B747-40095862.9 Flight hours11064 Flights

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

CombinedCombined correctedTouchdownTouchdown corrected

uro Hr pes ce enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

B747-40095862.9 Flight hours11064 Flights

A-4

FIGURE A-5. SUMMARY CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT BY 

GROUND PHASE (B-747-400) 

FIGURE A-6. SUMMARY CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT HOUR BY 

GROUND PHASE (B-747-400) 
A-5

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi outTakeoff rollLanding rollTurn offTaxi inCombined

ur Horepsecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

B767-20044990 Flight hours6551 Flights

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out Takeoff rollLanding rollTurn off Taxi inCombined

thgilFrepsecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

B767-20044990 Flight hours6551 Flights

FIGURE A-7. CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT BY 

GROUND PHASE (B-767-200) 

FIGURE A-8. CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT HOUR BY 

GROUND PHASE (B-767-200) 
A-6

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out correctedTakeoff roll correctedLanding roll correctedTurn off correctedTaxi in correctedCombined corrected

htgil Fr pe ces enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

B767-20044990 Flight hours6551 Flights

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out correctedTakeoff roll correctedLanding roll correctedTurn off correctedTaxi in correctedCombined corrected

ruo Hr pe ces enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

B767-20044990 Flight hours6551 Flights

FIGURE A-9. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT 

BY GROUND PHASE (B-767-200) 

FIGURE A-10. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT HOUR 

BY GROUND PHASE (B-767-200) 
10-6

10-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

CombinedCombined correctedTouchdownTouchdown corrected

htgi Fl r pes ce enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

B767-20044990 Flight hours6551 Flights

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

CombinedCombined correctedTouchdownTouchdown corrected

uro Hr pes ce enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

B767-20044990 Flight hours6551 Flights

A-7

FIGURE A-11. SUMMARY CUMULATIVE OCCURRENCES 

OF LATERAL LOAD FACTOR PER FLIGHT BY 

GROUND PHASE (B-767-200) 

FIGURE A-12. SUMMARY CUMULATIVE OCCURRENCES 

OF LATERAL LOAD FACTOR PER FLIGHT HOUR 

BY GROUND PHASE (B-767-200) 
10-6

10-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out Takeoff rollLanding rollTurn off Taxi inCombined

thgilFr pe s ce enrrucc Oevtia muluC

Lateral Load Factor Ny, (g)

B737-40089269 Flight hours60734 Flights

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out Takeoff rollLanding rollTurn off Taxi inCombined

uroHrepsecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

B737-40089269 Flight hours60734 Flights

A-8

FIGURE A-13. CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT BY 

GROUND PHASE (B-737-400) 

FIGURE A-14. CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT HOUR 

BY GROUND PHASE (B-737-400) 
A-9

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out correctedTakeoff roll correctedLanding roll correctedTurn off correctedTaxi in corrected Combined corrected

htgil Fr pe ces enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

B737-40089269 Flight hours60734 Flights

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out correctedTakeoff roll correctedLanding roll correctedTurn off correctedTaxi in correctedCombined corrected

htgil Fr pe ces enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

B737-40089269 Flight hours60734 Flights

FIGURE A-15. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT 

BY GROUND PHASE (B-737-400) 

FIGURE A-16. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT HOUR 

BY GROUND PHASE (B-737-400) 
10-6

10-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

CombinedCombined correctedTouchdownTouchdown corrected

uro Hr pes ce enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

B737-40089269 Flight hours60734 Flights

A-10

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

CombinedCombined correctedTouchdownTouchdown corrected

htgi Fl r pes ce enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

B737-40089269 Flight hours60734 Flights

FIGURE A-17. SUMMARY CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT BY 

GROUND PHASE (B-737-400) 

FIGURE A-18. SUMMARY CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT HOUR BY 

GROUND PHASE (B-737-400) 
10-6

10-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi outTakeoff rollLanding rollTurn off Taxi inCombined

ur Horepsecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

CRJ463.5 Flight hours359 Flights

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out Takeoff rollLanding rollTurn off Taxi inCombined

thgilFrepsecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

CRJ463.5 Flight hours359 Flights

A-11

FIGURE A-19. CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT BY 

GROUND PHASE (CRJ100) 

FIGURE A-20. CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT HOUR BY 

GROUND PHASE (CRJ100) 
A-12

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out correctedTakeoff roll correctedLanding roll correctedTurn off correctedTaxi in correctedCombined corrected

htgil Fr pe s ce enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

CRJ463.5 Flight hours359 Flights

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out correctedTakeoff roll correctedLanding roll correctedTurn off corrected Taxi in corrected Combined corrected

ruo Hr pe s ce enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

CRJ463.5 Flight hours359 Flights

FIGURE A-21. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT BY 

GROUND PHASE (CRJ100) 

FIGURE A-22. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT 

HOUR BY GROUND PHASE (CRJ100) 
10-6

10-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

CombinedCombined correctedTouchdownTouchdown corrected

htgi Fl r pes ce enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

CRJ463.5 Flight hours359 Flights

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

CombinedCombined correctedTouchdownTouchdown corrected

uro Hr pes ce enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

CRJ463.5 Flight hours359 Flights

A-13

FIGURE A-23. SUMMARY CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT BY 

GROUND PHASE (CRJ100) 

FIGURE A-24. SUMMARY CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT HOUR BY 

GROUND PHASE (CRJ100) 
A-14

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out Takeoff rollLanding rollTurn off Taxi inCombined

thgilFrepsecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

A32033541.9 Flight hours10066 Flights

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out Takeoff rollLanding rollTurn off Taxi inCombined

ur Horepsecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

A32033541.9 Flight hours10066 Flights

FIGURE A-25. CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT BY 

GROUND PHASE (A320) 

FIGURE A-26. CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT HOUR BY 

GROUND PHASE (A320) 
A-15

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out correctedTakeoff roll correctedLanding roll correctedTurn off correctedTaxi in correctedCombined corrected

htgil Fr pe ces enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

A32033541.9 Flight hours10066 Flights

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Taxi out correctedTakeoff roll correctedLanding roll correctedTurn off correctedTaxi in corrected Combined corrected

ruo Hr pe ces enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

A32033541.9 Flight hours10066 Flights

FIGURE A-27. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER 

FLIGHT BY GROUND PHASE (A320) 

FIGURE A-28. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT HOUR 

BY GROUND PHASE (A320) 
10-6

10-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

CombinedCombined correctedTouchdownTouchdown corrected

htgi Fl r pes ce enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

A32033541.9 Flight hours10066 Flights

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

CombinedCombined correctedTouchdownTouchdown corrected

uro Hr pes ce enrrucc O ve tialumuC

Lateral Load Factor Ny, (g)

A32033541.9 Flight hours10066 Flights

A-16

FIGURE A-29. SUMMARY CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT BY 

GROUND PHASE (A320) 

FIGURE A-30. SUMMARY CUMULATIVE OCCURRENCES OF 

LATERAL LOAD FACTOR PER FLIGHT HOUR 

BY GROUND PHASE (A320) 
10-6

10-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 taxiout CRJ taxioutA320 taxioutB737-400 taxiout B767-200 taxiout 

thgilFr epse enc rrucc OevtialumuC

Lateral Load Factor Ny, (g)

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 taxiout CRJ100 taxioutA320 taxioutB737-400 taxiout B767-200 taxiout 

ruoHr epse enc rrucc OevtialumuC

Lateral Load Factor Ny, (g)

A-17

FIGURE A-31. CUMULATIVE OCCURRENCES OF LATERAL 

LOAD FACTOR PER FLIGHT DURING TAXI-OUT BY 

AIRCRAFT MODEL 

FIGURE A-32. CUMULATIVE OCCURRENCES OF LATERAL 

LOAD FACTOR PER FLIGHT HOUR DURING TAXI-OUT 

BY AIRCRAFT MODEL 
A-18

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 Takeoff rollCRJ Takeoff rollA320 Takeoff rollB737-400 Takeoff rollB767-200 Takeoff roll

thgilFr epse enc rrucc OevtialumuC

Lateral Load Factor Ny, (g)

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 Takeoff rollCRJ100 Takeoff rollA320 Takeoff rollB737-400 Takeoff rollB767-200 Takeoff roll

ruoHr epse enc rrucc OevtialumuC

Lateral Load Factor Ny, (g)

FIGURE A-33. CUMULATIVE OCCURRENCES OF LATERAL 

LOAD FACTOR PER FLIGHT DURING TAKEOFF ROLL BY 

AIRCRAFT MODEL 

FIGURE A-34. CUMULATIVE OCCURRENCES OF LATERAL 

LOAD FACTOR PER FLIGHT HOUR DURING TAKEOFF 

ROLL BY AIRCRAFT MODEL 
A-19

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 TouchdownCRJ TouchdownA320 TouchdownB737-400 TouchdownB767-200 Touchdown

thgilFr pesecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 TouchdownCRJ100 TouchdownA320 TouchdownB737-400 TouchdownB767-200 Touchdown

ru Hor pesecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

FIGURE A-35. CUMULATIVE OCCURRENCES OF LATERAL 

LOAD FACTOR PER FLIGHT DURING TOUCHDOWN 

BY AIRCRAFT MODEL 

FIGURE A-36. CUMULATIVE OCCURRENCES OF LATERAL 

LOAD FACTOR PER FLIGHT HOUR DURING 

TOUCHDOWN BY AIRCRAFT MODEL 
10-6

10-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 Landing rollCRJ100 Landing roll A320 Landing rollB737-400 Landing rollB767-200 Landing roll

ruoHr epse enc rrucc OevtialumuC

Lateral Load Factor Ny, (g)

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 Landing rollCRJ100 Landing roll A320 Landing rollB737-400 Laning rollB767-200 Landing roll

thgilFr pesecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

A-20

FIGURE A-37. CUMULATIVE OCCURRENCES OF LATERAL 

LOAD FACTOR PER FLIGHT DURING LANDING ROLL BY 

AIRCRAFT MODEL 

FIGURE A-38. CUMULATIVE OCCURRENCES OF LATERAL 

LOAD FACTOR PER FLIGHT HOUR DURING LANDING 

ROLL BY AIRCRAFT MODEL 
10-6

10-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 Turn off CRJ Turn off A320 Turn off B737-400 TurnoffB767-200 Turnoff

thgilFr pesecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 Turn off CRJ100 Turn offA320 Turn off B737-400 TurnoffB767-200 Turnoff

ru Hor pesecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

A-21

FIGURE A-39. CUMULATIVE OCCURRENCES OF LATERAL 

LOAD FACTOR PER FLIGHT DURING RUNWAY 

TURNOFF BY AIRCRAFT MODEL 

FIGURE A-40. CUMULATIVE OCCURRENCES OF LATERAL 

LOAD FACTOR PER FLIGHT HOUR DURING RUNWAY 

TURNOFF BY AIRCRAFT MODEL 
A-22

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 Taxi inCRJ100 Taxi inA320 Taxi inB737-400 Taxi inB767-200 Taxi in

thgi Flr pes cenerrucc O veitalumuC

Lateral Load Factor Ny, (g)

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 Taxi inCRJ500 Taxi inA320 Taxi inB737-400 Taxi inB767-200 Taxi in

ru Hor pes cenerrucc O veitalu Cum

Lateral Load Factor Ny, (g)

FIGURE A-41. CUMULATIVE OCCURRENCES OF LATERAL 

LOAD FACTOR PER FLIGHT DURING TAXI-IN BY 

AIRCRAFT MODEL 

FIGURE A-42. CUMULATIVE OCCURRENCES OF LATERAL 

LOAD FACTOR PER FLIGHT DURING TAXI-IN BY 

AIRCRAFT MODEL 
10-6

10-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

ru Horepsecnerr cu Ocevitalu Cum

Lateral Load Factor Ny, (g)

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 taxi out correctedCRJ100 taxi out correctedA320 taxi out correctedB737-400 taxi out correctedB767-200 taxi out corrected

A-23

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 taxi out correctedCRJ100 taxi out correctedA320 taxi out correctedB737-400 taxi out correctedB767-200 taxi out corrected

thgi Flr pes cenerrucc O veitalumuC

Lateral Load Factor Ny, (g)

FIGURE A-43. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT DURING 

TAXI-OUT BY AIRCRAFT MODEL 

FIGURE A-44. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT HOUR 

DURING TAXI-OUT BY AIRCRAFT MODEL 
A-24

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

thgilFr pe s ce enrrucc OevitalumuC

Lateral Load Factor Ny, (g)

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 takeoff roll correctedCRJ100 takeoff roll correctedA320 takeoff roll correctedB737-400 takeoff roll correctedB767-200 takeoff roll corrected

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 takeoff roll correctedCRJ100 takeoff roll correctedA320 takeoff roll correctedB737-400 takeoff roll correctedB767-200 takeoff roll corrected

ru Hor pesecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

FIGURE A-45. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT DURING 

TAKEOFF ROLL BY AIRCRAFT MODEL 

FIGURE A-46. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT HOUR 

DURING TAKEOFF ROLL BY AIRCRAFT MODEL 
A-25

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 touchdown correctedCRJ100 touchdown correctedA320 touchdown correctedB737-400 touchdown correctedB767-200 touchdown corrected

thgilFr epse enc rrucc OevtialumuC

Lateral Load Factor Ny, (g)

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

ru Horepsecnerr cuc ve Oitalu Cum

Lateral Load Factor Ny, (g)

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 touchdown correctedCRJ100 touchdown correctedA320 touchdown correctedB737-400 touchdown correctedB767-200 touchdown corrected

FIGURE A-47. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT DURING 

TOUCHDOWN BY AIRCRAFT MODEL 

FIGURE A-48. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT HOUR 

DURING TOUCHDOWN BY AIRCRAFT MODEL 
10-6

10-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 Landing roll correctedCRJ500 Landing roll correctedA320 Landing roll correctedB737-400 Landing roll correctedB767-200 Landing roll corrected 

ru Horepsecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

A-26

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 Landing roll correctedCRJ500 Landing roll correctedA320 Landing roll correctedB737-400 Landing roll correctedB767-200 Landing roll corrected

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Lateral Load Factor Ny, (g)

FIGURE A-49. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT DURING 

LANDING ROLL BY AIRCRAFT MODEL 

FIGURE A-50. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT HOUR 

DURING LANDING ROLL BY AIRCRAFT MODEL 
A-27

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 Turnoff correctedCRJ500 Turnoff correctedA320 Turnoff corrected B737-400 Turnoff correctedB767-200 Turnoff corrected

thgilFrepsecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 Turnoff correctedCRJ500 Turnoff correctedA320 Turnoff corrected B737-400 Turnoff correctedB767-200 Turnoff corrected

ru Horepsecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

FIGURE A-51. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT DURING 

RUNWAY TURNOFF BY AIRCRAFT MODEL 

FIGURE A-52. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT HOUR 

DURING RUNWAY TURNOFF BY AIRCRAFT MODEL 
A-28

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 Taxi in correctedCRJ500 Taxi in correctedA320 Taxi in corrected B737-400 Taxi in correctedB767-200 Taxi in corrected

thgilFrepsecnerr cuc O veitalu Cum

Lateral Load Factor Ny, (g)

10-610-510-410-310-210-1

100101102103

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

B747-400 Taxi in correctedCRJ500 Taxi in correctedA320 Taxi in corrected B737-400 Taxi in correctedB767-200 Taxi in corrected

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Lateral Load Factor Ny, (g)

FIGURE A-53. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT DURING 

TAXI-IN BY AIRCRAFT MODEL 

FIGURE A-54. CUMULATIVE OCCURRENCES OF (RECORDED 

WEIGHT/MAX LANDING WEIGHT)*Ny PER FLIGHT HOUR 

DURING TAXI-IN BY AIRCRAFT MODEL