4-1 CHAPTER 4. OPERATOR REPORTING SYSTEMS AND FAA OVERSIGHT
4.1 Pilot and Agent Reporting Systems.
4.1.1 What are the Pilot’s and Operator’s Responsibilities in Reporting Aircraft Loading and Manifest Preparation Discrepancies? Each operator should develop a reporting system and encourage employees to report any discrepancies in aircraft loading or manifest preparation. These discrepancies may include errors in documentation or calculation, or issues with aircraft performance and handling qualities that indicate the aircraft weight or balance is not accurate. Operators should determine the cause of each discrepancy and take appropriate corrective action. This would include a load audit on affected flights or conducting a passenger or bag weight survey in accordance with this advisory circular (AC) if trends indicate it is warranted.
Note 1: Section 121.665 states, “each certificate holder is responsible for the preparation and accuracy of a load manifest form before each takeoff.” The FAA, however, encourages operators to develop a reporting system in order to account for any discrepancies or errors in documentation and to determine the cause of each discrepancy, in the interest of reducing the likelihood that load manifests contain incorrect information.
Note 2: While accountability for compliance with § 121.665 must be based on the original manifest, an operator is not barred from taking any corrective action determined by their safety management system (SMS) to have a positive impact on the safety of any continuing flight. For example, an operator may prepare a separate, amended manifest if the flightcrew might unknowingly exceed the maximum certified landing weight or other safety limitation without the amendment.
4.2 FAA Oversight.
4.2.1 Which FAA Inspectors are Responsible for Approving and Oversight of an Operator’s W&B Program? The FAA has divided the responsibility of approving and oversight of an operator’s W&B control program between the operator’s principal inspectors (PI) in the certificate management office (CMO) or Flight Standards District Office (FSDO). An operator that wishes to change aspects of its W&B control program, including average weights, should submit all applicable supporting data (part 121 operators) to include a safety risk assessment to the PIs and for approval. If the FAA approves the changes, the FAA will issue revised operations specifications (OpSpecs), management specifications (MSpecs), or Letter of Authorization (LOA), as appropriate.
4.2.2 Which Portions of OpSpecs or MSpecs are Relevant to an Operator’s W&B Program?
This AC details methods to develop a W&B control program with greater accuracy and increased flexibility. By changing its OpSpecs or MSpecs, an operator may alter the weights used in its W&B control program to include appropriate combinations of standard average weights, average weights based on survey results, or actual weights.
4-2
4.2.2.1 OpSpec or MSpec Parts A and E will address:
1. Average passenger and average bag weights by survey;
2. Situations when the use of average weights is inappropriate;
3. The treatment of charter flights or special groups, if applicable;
4. The type of loading schedule and instructions for its use;
5. Aircraft weighing schedules; and
6. Other procedures that the operator may require to assure accuracy of their control of W&B program.
4.2.2.2 OpSpec or MSpec E096, Aircraft Weighing, is issued to an operator with an approved aircraft weight program. The FAA issues this paragraph after reviewing and approving the operator’s aircraft W&B control procedures in their entirety.
4.2.2.3 OpSpec or MSpec A011, Approved Carry-On Baggage Program, is issued to an operator with an approved carry-on bag program. This paragraph provides details about the operator’s approved carry-on bag program and states whether the operator has a carry-on bag program or a no-carry-on bag program. The FAA will issue this paragraph after reviewing the operator’s carry-on baggage program in its entirety.
4.2.2.4 If an operator chooses to use standard average passenger weights as outlined in this AC, the FAA will document that decision by issuing one or more of the following OpSpecs or MSpecs. If an operator proposes to use weights other than the standard average weights, and if the FAA concurs with the statistically valid data provided by the operator to support such average weights, the weights will be documented in the following OpSpecs or MSpecs. Although the following OpSpecs and MSpecs authorize an operator to use average weights, an operator may use actual weights at any time once issued these paragraphs.
1. OpSpec/MSpec A097, Small Cabin Aircraft Passenger and Baggage Weight Program.
2. OpSpec/MSpec A098, Medium Cabin Aircraft Passenger and Baggage Weight Program.
3. OpSpec/MSpec A099, Large Cabin Aircraft Passenger and Baggage Weight Program.
Note: If an operator does not provide the FAA with adequate information to justify the issuance of one of the above paragraphs that documents the use of standard average, survey-derived average, the FAA may issue OpSpec/MSpec A096, Actual Passenger and Baggage
4-3 Weight Program for All Aircraft, which authorizes the operator to use only actual passenger and bag weights.
4.2.2.5 If an operator chooses to develop a W&B control program using only actual weights for all the aircraft it operates, the FAA will issue OpSpec/MSpec A096. The FAA will not issue OpSpec/MSpec A097, A098, or A099 to operators with a W&B control program that uses only actual weights. The FAA will only issue OpSpecs/MSpecs A096, A097, A098, and/or A099 after reviewing the operator’s actual or average weight program.
4.2.2.6 An operator that receives approval to use survey-derived (nonstandard) average weights should document and make available, upon request, the data and methodology used to derive those weights. An operator’s documentation should be sufficiently comprehensive to allow the FAA to reproduce the same results during an audit. An operator should retain this documentation for as long as the operator uses the survey-derived average weights in its W&B control program. See paragraph 3.3.8 for when to revalidate survey-derived (nonstandard) average weights.
4.2.2.7 If an operator chooses to conduct a survey, the operator will use the results of the survey to establish a revised average weight and must curtail the loading envelope as necessary. Once approved by the FAA, the appropriate OpSpecs, MSpecs, or LOA will be issued.
4.2.2.8 For operators using an onboard W&B system to determine the W&B of the aircraft, the FAA will issue OpSpec or MSpec A096. OpSpec/MSpec A096 documents the use of actual weights and the use of its onboard W&B system.
For an operator that chooses to use standard average weights as a backup system, the FAA will issue OpSpec/MSpec A097, A098, or A099, as appropriate. By authorizing the use of average weights, the operator may elect to use actual weights derived from its onboard W&B system, and may use average weights as an alternative should the system be inoperative.
4.2.2.9 For operators conducting all-cargo operations, the FAA will issue OpSpec A096. OpSpec/MSpec A096 documents the use of actual weights, with the exception of flightcrew and the weights of flightcrew bags. These weights may be accounted for using the standard average weights described in Table 3-2.
Appendix A A-1 APPENDIX A. DEFINITIONS A.1 Balance Arm (BA). The horizontal distance from the reference datum to the CG of an item.
A.2 Basic Empty Weight (BEW). The aircraft empty weight, adjusted for variations in standard items.
A.3 Basic Operating Weight (BOW). The empty weight of the aircraft plus the weight of the required crew, their baggage, and other standard items such as meals and potable water.
A.4 Cargo. As used in this advisory circular (AC), any property carried on an aircraft other than mail, stores, and accompanied or mishandled baggage.
A.5 Carry-On Bag. A bag that the operator allows the passenger to carry on board. It should be of a size and shape that will allow it to be stowed under the passenger seat or in a storage compartment. The operator establishes the exact dimensional limits based on the particular aircraft stowage limits.
A.6 Certificated Weight and Center of Gravity (CG) Limits. Weight and CG limits are established at the time of aircraft certification. They are specified in the applicable Airplane Flight Manual (AFM), Rotorcraft Flight Manual (RFM), or Weight and Balance Manual (WBM) as provided by the manufacturer.
A.7 Checked Bags. Checked bags are those bags placed in the cargo compartment of the aircraft. This includes bags that are too large to be placed in the cabin of the aircraft or those bags that are required to be carried in the cargo compartment by regulation, security program, or company policy. For bags checked planeside, see the definition for planeside loaded bags.
A.8 Curtailment. Creating an operational loading envelope that is more restrictive than the manufacturer’s CG envelope, to assure the aircraft will be operated within limits during all phases of flight. Curtailment typically accounts for, but is not limited to, in-flight movement, gear and flap movement, cargo variation, fuel density, fuel burn-off, and seating variation.
A.9 Datum. An imaginary vertical plane from which all horizontal distances are measured for balance purpose.
A.10 Fleet Operating Empty Weight (FOEW). Average operational empty weight (OEW) used for a fleet or group of aircraft of the same model and configuration.
A.11 Heavy Bags. Heavy bags are considered any bag that weighs more than 50 pounds but less than 100 pounds. Bags that are 100 pounds or more are considered cargo.
A.12 Large Cabin Aircraft. Aircraft originally certificated with a maximum seating capacity of 71 or more passenger seats.
Appendix A A-2 A.13 Loading Envelope. Weight and CG envelope used in a loading schedule. Loading the aircraft within the loading envelope will maintain the aircraft weight and CG throughout the flight within the limits established by the type certificate (TC) or Supplemental Type Certificate (STC) that applies to the aircraft.
A.14 Loading Schedule. Method for calculating and documenting aircraft Weight and Balance (W&B) prior to taxiing, to ensure the aircraft will remain within all required W&B limitations throughout the flight.
A.15 Maximum Landing Weight. The maximum weight at which the aircraft may normally be landed.
A.16 Maximum Takeoff Weight (MTOW). The maximum allowable aircraft weight at the start of the takeoff run.
A.17 Maximum Taxi Weight. The maximum allowable aircraft weight for taxiing.
A.18 Maximum Zero Fuel Weight (MZFW). The maximum permissible weight of an aircraft with no disposable fuel and oil.
A.19 Mean Aerodynamic Chord (MAC). The MAC is established by the manufacturer, which defines its leading edge and its trailing edge in terms of distance (usually inches) from the datum. The CG location and various limits are then expressed in percentages of the chord. The location and dimensions of the MAC can be found in the aircraft specifications, the type certificate data sheet (TCDS), the AFM, RFM, or the aircraft WBM.
A.20 Medium Cabin Aircraft. Aircraft originally certificated with a maximum seating capacity between 70 and 30 passenger seats, inclusive.
A.21 Moment. The moment is the product of a weight multiplied by its arm. The moment of an item about the datum is obtained by multiplying the weight of the item by its horizontal distance from the datum.
A.22 Onboard Weight and Balance (W&B) System. A system that weighs an aircraft and payload, then computes the CG using equipment onboard the aircraft.
A.23 Operational Items. Personnel, equipment, and supplies necessary for a particular operation but not included in BEW. These items may vary for a particular aircraft and may include, but are not limited to, the following:
1. Crewmembers and bags;
2. Manuals and navigation equipment;
3. Passenger service equipment, including pillows, blankets, and magazines;
4. Removable service equipment for cabin, galley, and bar;
5. Food and beverage, including liquor;
Appendix A A-3
6. Usable fluids, other than those in useful load;
7. Required emergency equipment for all flights;
8. Life rafts, life vests, and emergency transmitters;
9. Potable water;
10. Drainable unusable fuel;
11. Spare parts normally carried aboard and not accounted for as cargo; and
12. All other equipment considered standard by the operator.
A.24 Passenger Assist/Comfort Animals and Devices. These include, but are not limited to, canes, crutches, walkers, wheelchairs, and service animals.
A.25 Passenger Weight. Passenger weight is the actual weight or the approved average weight of the passenger.
1. An adult is defined as an individual 13 years or older.
2. A child is defined as an individual aged 2 to less than 13 years of age.
3. Infants are children who have not yet reached their second birthday and are considered part of the adult standard average passenger weight.
A.26 Personal Item. Items the operator may allow a passenger to carry on board, in addition to a carry-on bag. Typically, an operator may allow one personal item such as a purse, briefcase, computer and case, camera and case, diaper bag, or an item of similar size.
Other items, such as coats, umbrellas, reading material, food for immediate consumption, child restraint systems, and service animals, are allowed to be carried on the aircraft and are not counted against the personal item allowance.
A.27 Planeside Loaded Bag. Any bag or item that is placed at the door or steps of an aircraft and subsequently placed in the aircraft cargo compartment or cargo bin.
A.28 Roster Weight. The listing of a group of passengers specifically by name and weight.
A.29 Small Cabin Aircraft. Aircraft originally certificated with a maximum seating capacity between 5 and 29 passenger seats, inclusive.
A.30 Standard Deviation. One of several indexes of variability used to characterize dispersion among measures in a given population.
A.31 Standard Items. Equipment and fluids not considered an integral part of a particular aircraft and not a variation for the same type of aircraft. These items may include, but are not limited to, the following:
1. Unusable fuel and other unusable fluids;
2. Engine oil;
Appendix A A-4
3. Toilet fluid and chemical;
4. Fire extinguishers, pyrotechnics, and emergency oxygen equipment;
5. Structure in galley, buffet, and bar; and
6. Supplementary electronic equipment.
A.32 Type Certificate Data Sheet (TCDS). An FAA document that records the type certification data of a product (such as a control surface movement limits, operating limitations, placards, and W&B) that may also be available in the flight manual or maintenance manual in accordance with the current edition of FAA Order 8110.4, Type Certification. The TCDS is part of the TC, per 14 CFR part 21, § 21.41.
A.33 Useful Load. Difference between takeoff weight and BEW. It includes payload, usable fuel, and other usable fluids not included as operational items.
Appendix B B-1 APPENDIX B. SOURCE OF STANDARD AVERAGE WEIGHTS B.1 Standard Average Passenger Weights.
B.1.1 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.1.2 The CDC collects NHANES data annually by conducting an actual scale weighing of approximately 9,000 subjects in a clinical setting. The CDC normally publishes results every 4 years. Additional information on NHANES and the data points used to derive average weights are found at the following websites:
1. General information:
http://www.cdc.gov/nchs/nhanes.htm.
2. CDC body measurements for men and women 20 years and over:
http://www.cdc.gov/nchs/fastats/body-measurements.htm.
B.2 Standard Average Crewmember Weights.
B.2.1 The FAA Civil Aerospace Medical Institute (CAMI) publishes annually the Aerospace Medical Certification Statistical Handbook, which contains descriptive characteristics of all active U.S. civil aviation airmen. An operator’s use of reports from CAMI ensures the operator is using the most current version of the Handbook. The operator will use the proper medical class and establish a crewmember mean weight respective to their operation. These reports are found at: http://www.faa.gov/data_research/research/med_hu manfacs/oamtechreports/2010s/.
Appendix C C-1 APPENDIX C. SAMPLE OPERATIONAL LOADING ENVELOPE C.1 Introduction. The following is an example of how to develop an operational loading envelope. For this example, a hypothetical 19-seat normal category aircraft is used.
Although this example uses inches to measure fuselage station, an operator may choose to use an index system for convenience.
C.2 Assumptions for This Example.
C.2.1 Passenger Weight. Because the aircraft is certificated under the normal category of 14 CFR part 23, and because it is originally type certificated (TC) for five or more passenger seats, it would be appropriate in this example to use the weights derived in Chapter 3, Methods to Determine the Weight of Passengers, paragraph 3.2. For this example, it is assumed that the operator has a no-carry-on baggage program; therefore, it is also assumed 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.
C.2.2 Bag Weights. For this example, the operator assumes that a checked bag weighs 30 pounds and a planeside loaded bag weighs 20 pounds, based on the operator’s survey.
C.2.3 Interior Seating. For this example, consider a normal category 19-seat aircraft with the interior seating diagram shown in Figure C-1, Sample Aircraft Interior Seating Diagram.
For this example, the fuselage station (F.S.) of each seat row is the seated passenger centroid. (For other diagrams, this may not be true.)
Figure C-1. Sample Aircraft Interior Seating Diagram
Appendix C C-2 C.3 Curtailments for Passenger Seating Variation.
C.3.1 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.
C.3.2 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 C-1 through C-3 below.
Table C-1. Calculation of Zone 1 Centroid Row No. No. of Seats Row Location No. of Seats x 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 C-2. Calculation of Zone 2 Centroid Row No. No. of Seats Row Location No. of Seats x 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 C-3. Calculation of Zone 3 Centroid Row No. No. of Seats Row Location No. of Seats x 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
Appendix C C-3 C.3.3 Comparing Loading Assumptions. To determine the appropriate amount of curtailment, the operator should compare aircraft loading based on the window-aisle-remaining assumption 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 C-4 through C-12 below.
C.3.3.1 Curtailment Calculation for Zone 1.
Table C-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 C-5. Moments Resulting From the Window-Aisle-Remaining Assumption for Zone 1 Passenger No.
Assumed Row Assumed Weight Assumed 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 C-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 C C-4 Figure C-2. Sample Passenger Seating Moment (Zone 1) C.3.3.2 C urtailment Calculation for Zone 2.
Table C-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