Appendix 1
a. Unusable fuel and other unusable fluids;
b. Engine oil;
c. Toilet fluid and chemical;
d. Fire extinguishers, pyrotechnics, and emergency oxygen equipment;
e. Structure in galley, buffet, and bar; and
f. Supplementary electronic equipment.
32. Useful Load. Difference between takeoff weight and OEW. It includes payload, usable fuel, and other usable fluids not included as operational items.
Appendix 2 APPENDIX 2. SOURCE OF STANDARD AVERAGE WEIGHTS
1. Standard Average Passenger Weights.
a. The Federal Aviation Administration (FAA) examined data from several large-scale, national health studies conducted by U.S. Government health agencies. The FAA found that the National Health and Nutrition Examination Survey (NHANES), conducted by the Centers for Disease Control (CDC), provided the most comprehensive and appropriate data. The data in NHANES cover a broad spectrum of the general population, are based on a large sample size, and are not restricted geographically to a particular area.
b. The CDC collects NHANES data annually by conducting an actual scale weighing of approximately 9,000 subjects in a clinical setting. The standard deviation of the sample was 47 pounds. The CDC last published results from NHANES in 2000. Additional information on NHANES and the data points used to derive average weights in this advisory circular are at:
(1) General information.
http://www.cdc.gov/nchs/nhanes.htm
(2) Analytic and reporting guidelines.
http://www.cdc.gov/nchs/data/nhanes/nhanes3/nh3gui.pdf
(3) Data files for 1999–2000 survey.
http://www.cdc.gov/nchs/about/major/nhanes/NHANES99_00.htm
c. The FAA used the most recent NHANES data set available from surveys conducted in 1999 and 2000 to calculate the standard average passenger weights used in this advisory circular (AC). From this data set, the FAA separated out a separate data set of individuals who had not yet reached their 13th birthday to determine average child weight. From the remaining adult data set, the FAA removed all weight data that indicated the subject was clothed during the weighing and removed all data points more than two standard deviations from the mean. The FAA then calculated the average weights for males and females in the remaining data set.
2. Standard Average Bag Weights.
To determine standard average weights for different types of bags, the FAA closely examined previous surveys conducted by operators, including several surveys conducted in response to FAA Notice 8400.40, Weight and Balance Control Programs for 10 to 19 Seat Airplanes Operated Under 14 CFR 121. The results of those surveys are summarized in Table 2-1.
TABLE 2-1. BAG SURVEY RESULTS Item Surveyed Average Weight Standard Deviation Personal items and carry-on bags
15.1 lb 8.2 lb Checked bags 28.9 lb 10.8 lb Heavy bags 58.7 lb 7.2 lb Page 1 (and 2)
Appendix 3 APPENDIX 3. SAMPLE OPERATIONAL LOADING ENVELOPE
1. Introduction.
The following is an example of how to develop an operational loading envelope. For this example, a hypothetical 19-seat commuter category aircraft is used. Although this example uses inches to measure fuselage station, an operator may choose to use an index system for convenience.
2. Assumptions for This Example.
a. Passenger weight. Because the aircraft is certificated under the commuter category of Title 14 of the Code of Federal Regulations (14 CFR) part 23 and because it is originally typecertificated for 5 or more passenger seats, it would be appropriate to use the average weights listed in Chapter 2, Section 2. For this example, it is assumed that the operator has a no-carry-on baggage program. Therefore, the operator should use a standard average passenger weight of 189 pounds in winter and 184 pounds in summer. For this example, a standard average passenger weight of 189 pounds is used. The operator also assumes that passengers are distributed throughout the cabin in accordance with the window-aisle-remaining method. Note that because this aircraft has only two window seats per row, the operator may reasonably assume that passengers begin seating themselves in the front of the cabin and select the most forward seat available.
b. Bag weights. For this example, the operator assumes that a checked bag weighs 30 pounds and a plane-side loaded bag weighs 20 pounds.
c. Interior seating. For this example, consider a commuter category 19-seat aircraft with the interior seating diagram shown in Figure 3-1. For this example, the fusleage station (F.S.) of each seat row is the seated passenger centroid. (For other diagrams this may not be true.)
(Diagram courtesy of Raytheon Aircraft Company) FIGURE 3-1. SAMPLE AIRCRAFT INTERIOR SEATING DIAGRAM
Appendix 3
3. Curtailments for Passenger Seating Variation.
a. Establishing zones. The operator elects to separate the passenger cabin into three zones.
Zone 1 will contain rows 1 to 3, zone 2 will contain rows 4 to 6, and zone 3 will contain rows 7 to 9.
b. Determining the centroid of each zone. When using cabin zones, an operator assumes that all passengers are sitting at the centroid of their zone. To find the centroid of each zone—
(1) Multiply the number of seats in each row of the zone by the location of the row,
(2) Add each number calculated in step 1, and
(3) Divide the number in step 2 by the total number of seats in the zone.
NOTE: For this sample aircraft, see Tables 3-1 through 3-3 below.
TABLE 3-1. CALCULATION OF ZONE 1 CENTROID Row No. No. of Seats Row Location No. of Seats × Row Location 1 2 198 in 396 in 2 2 228 in 456 in 3 2 258 in 516 in TOTAL 6 NA 1,368 in 1,368 in / 6 seats = 228 in
TABLE 3-2. CALCULATION OF ZONE 2 CENTROID Row No. No. of Seats Row Location No. of Seats × Row Location 4 2 289 in 578 in 5 2 318 in 636 in 6 2 347 in 694 in TOTAL 6 NA 1,908 in 1,908 in / 6 seats = 318 in
TABLE 3-3. CALCULATION OF ZONE 3 CENTROID Row No. No. of Seats Row Location No. of Seats × Row Location 7 2 377 in 754 in 8 2 407 in 814 in 9 3 436 in 1,308 in TOTAL 7 NA 2,876 in 2,876 in / 7 seats = 411 in
c. Comparing loading assumptions. To determine the appropriate amount of curtailment, the operator should compare aircraft loading based on the window-aisle-remaining assumption Page 2
Appendix 3 with aircraft loaded based on the assumption that passengers are sitting at the centroid of their respective zones. An operator may determine the appropriate curtailment by comparing the moments resulting from these assumptions and identifying the loading scenarios that result in the most forward or aft center of gravity (CG) location. See Tables 3-4 through 3-12 below.
(1) Curtailment calculation for zone 1.
TABLE 3-4. MOMENTS RESULTING FROM THE ZONE CENTROID ASSUMPTION FOR ZONE 1 Passenger No.
Assumed Weight Assumed Arm Moment Cumulative Moment 1 189 lb 228 in 43,092 in-lb 43,092 in-lb 2 189 lb 228 in 43,092 in-lb 86,184 in-lb 3 189 lb 228 in 43,092 in-lb 129,276 in-lb 4 189 lb 228 in 43,092 in-lb 172,368 in-lb 5 189 lb 228 in 43,092 in-lb 215,460 in-lb 6 189 lb 228 in 43,092 in-lb 258,552 in-lb
TABLE 3-5. MOMENTS RESULTING FROM THE WINDOW-AISLE-REMAINING ASSUMPTION FOR ZONE 1 Passenger No.
Assumed Row Weight Arm Moment Cumulative Moment 1 1 189 lb 198 in 37,422 in-lb 37,422 in-lb 2 1 189 lb 198 in 37,422 in-lb 74,844 in-lb 3 2 189 lb 228 in 43,092 in-lb 117,936 in-lb 4 2 189 lb 228 in 43,092 in-lb 161,028 in-lb 5 3 189 lb 258 in 48,762 in-lb 209,790 in-lb 6 3 189 lb 258 in 48,762 in-lb 258,552 in-lb
TABLE 3-6. COMPARISON OF MOMENTS FOR ZONE 1 Passenger No.
Cumulative Moment from the Zone Centroid Assumption Cumulative Moment from the Window-Aisle-Remaining Assumption Difference 1 43,092 in-lb 37,422 in-lb -5,670 in-lb 2 86,184 in-lb 74,844 in-lb -11,340 in-lb 3 129,276 in-lb 117,936 in-lb -11,340 in-lb 4 172,368 in-lb 161,028 in-lb -11,340 in-lb 5 215,460 in-lb 209,790 in-lb -5,670 in-lb 6 258,552 in-lb 258,552 in-lb 0 in-lb
Appendix 3
Sample Development of Passenger Seating Curtailment Cabin Zone 1 0 200 400 600 800 1000 1200 1400 275 280 285 290 295 300 Fuselage Station (Inches Aft of Datum) Passenger Weight - pounds Forward Seating Moment Aft Seating Moment Possible Seating Moment Variation within Passenger Cabin Zone FIGURE 3-2. SAMPLE PASSENGER SEATING MOMENT (ZONE 1)
(2) Curtailment calculation for zone 2.
TABLE 3-7. MOMENTS RESULTING FROM THE ZONE CENTROID ASSUMPTION FOR ZONE 2 Passenger No.
Assumed Weight Assumed Arm Moment Cumulative Moment 7 189 lb 318 in 60,102 in-lb 60,102 in-lb 8 189 lb 318 in 60,102 in-lb 120,204 in-lb 9 189 lb 318 in 60,102 in-lb 180,306 in-lb 10 189 lb 318 in 60,102 in-lb 240,408 in-lb 11 189 lb 318 in 60,102 in-lb 300,510 in-lb 12 189 lb 318 in 60,102 in-lb 360,612 in-lb
Appendix 3 TABLE 3-8. MOMENTS RESULTING FROM THE WINDOW-AISLE-REMAINING ASSUMPTION FOR ZONE 2 Passenger No.
Assumed Row Weight Arm Moment Cumulative Moment 7 4 189 lb 289 in 54,621 in-lb 54,621 in-lb 8 4 189 lb 289 in 54,621 in-lb 109,242 in-lb 9 5 189 lb 318 in 60,102 in-lb 169,344 in-lb 10 5 189 lb 318 in 60,102 in-lb 229,446 in-lb 11 6 189 lb 347 in 65,583 in-lb 295,029 in-lb 12 6 189 lb 347 in 65,583 in-lb 360,612 in-lb
TABLE 3-9. COMPARISON OF MOMENTS FOR ZONE 2 Passenger No.
Cumulative Moment from the Zone Centroid Assumption Cumulative Moment from the Window-Aisle-Remaining Assumption Difference 7 60,102 in-lb 54,621 in-lb -5,481 in-lb 8 120,204 in-lb 109,242 in-lb -10,962 in-lb 9 180,306 in-lb 169,344 in-lb -10,962 in-lb 10 240,408 in-lb 229,446 in-lb -10,962 in-lb 11 300,510 in-lb 295,029 in-lb -5,481 in-lb 12 360,612 in-lb 360,612 in-lb 0 in-lb
Appendix 3
Sample Development of Passenger Seating Curtailment Cabin Zone 2 0 200 400 600 800 1000 1200 1400 275 280 285 290 295 300 Fuselage Station (Inches Aft of Datum) Passenger Weight - pounds Forward Seating Moment Aft Seating Moment Possible Seating Moment Variation within Passenger Cabin Zone FIGURE 3-3. SAMPLE PASSENGER SEATING MOMENT (ZONE 2)
(3) Curtailment calculation for zone 3.
TABLE 3-10. MOMENTS RESULTING FROM THE ZONE CENTROID ASSUMPTION FOR ZONE 3 Passenger No.
Assumed Weight Assumed Arm Moment Cumulative Moment 13 189 lb 411 in 77,679 in-lb 77,679 in-lb 14 189 lb 411 in 77,679 in-lb 155,358 in-lb 15 189 lb 411 in 77,679 in-lb 233,037 in-lb 16 189 lb 411 in 77,679 in-lb 310,716 in-lb 17 189 lb 411 in 77,679 in-lb 388,395 in-lb 18 189 lb 411 in 77,679 in-lb 466,074 in-lb 19 189 lb 411 in 77,679 in-lb 543,753 in-lb
Appendix 3 TABLE 3-11. MOMENTS RESULTING FROM THE WINDOW-AISLE-REMAINING ASSUMPTION FOR ZONE 3 Passenger No.
Assumed Row Weight Arm Moment Cumulative Moment 13 7 189 lb 377 in 71,253 in-lb 71,253 in-lb 14 7 189 lb 377 in 71,253 in-lb 142,506 in-lb 15 8 189 lb 407 in 76,923 in-lb 219,429 in-lb 16 8 189 lb 407 in 76,923 in-lb 296,352 in-lb 17 9 189 lb 436 in 82,404 in-lb 378,756 in-lb 18 9 189 lb 436 in 82,404 in-lb 461,160 in-lb 19 9 189 lb 436 in 82,404 in-lb 543,564 in-lb
TABLE 3-12. COMPARISON OF MOMENTS FOR ZONE 3 Passenger No.
Cumulative Moment from the Zone Centroid Assumption Cumulative Moment from the Window-Aisle-Remaining Assumption Difference 13 77,679 in-lb 71,253 in-lb -6,426 in-lb 14 155,358 in-lb 142,506 in-lb -12,852 in-lb 15 233,037 in-lb 219,429 in-lb -13,608 in-lb 16 310,716 in-lb 296,352 in-lb -14,364 in-lb 17 388,395 in-lb 378,756 in-lb -9,639 in-lb 18 466,074 in-lb 461,160 in-lb -4,914 in-lb 19 543,753 in-lb 543,564 in-lb -189 in-lb
Appendix 3
Sample Development of Passenger Seating Curtailment Cabin Zone 3 0 200 400 600 800 1000 1200 1400 1600 275 280 285 290 295 300 Fuselage Station (Inches Aft of Datum) Passenger Weight - pounds Forward Seating Moment Aft Seating Moment Possible Seating Moment Variation within Passenger Cabin Zone FIGURE 3-4. SAMPLE PASSENGER SEATING MOMENT (ZONE 3)
(4) Determining the most adverse loading. It is important that an operator examine the above results (from Tables 3-4 through 3-12) for each zone and determine which loading scenario results in the greatest difference in moments. For zones 1 and 2, having two, three, or four passengers in the zone results in the largest difference between the moments. For zone 3, having four passengers in the zone results in the largest difference. In this case, the operator should curtail the manufacturer’s loading envelope forward and aft by the sum of these moments, 36,666 inch-pounds, to account for the potential variation in passenger seating. In this example, the 36,666 inch-pounds is the sum of 11,340 from Table 3-6; 10,962 from Table 3-9; and 14,364 from Table 3-12.
(5) Using actual seating location. Alternatively, an operator may reasonably avoid the above curtailment calculations by determining the actual seating location of each passenger in the cabin. By eliminating potential variation in passenger seating, an operator would not need to make assumptions about passenger seating and would not need to curtail the loading envelope accordingly. An operator choosing to use actual seating location should have procedures in place to ensure that passengers sit in their assigned location.
Appendix 3
4. Other Curtailments to the Manufacturer’s Loading Envelope.
a. Variation in passenger weight. Because the operator in this example elects to use standard average weights on a small-cabin aircraft, an additional curtailment for potential variation in passenger weight is required. The operator should curtail the manufacturer’s loading envelope as described in Appendix 4.
b. Variation in fuel density. Because the loading of fuel does not significantly change the CG of the aircraft, the operator would not need to provide a curtailment for variation in fuel density.
c. Fuel movement in flight. For this sample aircraft, the manufacturer has considered the movement of fuel in flight. Therefore, the operator does not need to include additional curtailments in the operational loading envelope.
d. Fluids. The sample aircraft does not have a lavatory or catering.
e. Bags and freight. The sample aircraft has an aft bag compartment split into two sections.
If the operator has procedures in place to restrict the movement of bags between the two sections, no additional curtailment to the envelope is required.
f. In-flight movement of passengers and crewmembers. Because there are no flight attendants and the aircraft is not equipped with a lavatory, it is reasonable to assume that passengers or crewmembers will not move about the cabin in flight.
g. Movement of flaps and landing gear. The manufacturer of the sample aircraft has considered the movement of flaps and landing gear in the development of its loading envelope.
The operator does not need to include any additional curtailments in its operational loading envelope for the movement of those items.
h. Fuel consumption. The fuel vector for the sample aircraft provides a small aft movement that requires a -8,900 inch-pounds curtailment to the aft zero fuel weight limits to ensure the aircraft does not exceed the aft limit as fuel is burned. This equates to a -0.8 inch curtailment at an estimated operational empty weight of 11,000 pounds with a linear transition to a -0.6 inch curtailment at maximum zero fuel weight (MZFW) of 16,155 pounds. In this example, the 8,900 inch-pounds is the fuel burn deviation that would bring the aircraft outside the aft CG limit during the course of flight.
5. Operational Loading Envelope Diagrams.
a. Figure 3-5 below shows the operator’s curtailments to the manufacturer’s loading envelope, based on the assumptions made about variations in passenger seating and weight, as well as fuel consumption.