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3.2.2.6 The standard average crewmember weights established by the operator will be provided to the FAA for review and approval and issued through the operator’s OpSpecs, MSpecs, or LOA, as applicable.
3.2.3 What Weights May Be Used for Company Materials (COMAT), Freight, and Mail?
3.2.3.1 COMAT and Freight. An operator should use actual weights for company materials, aircraft parts, and freight carried aboard an aircraft.
3.2.3.2 Mail. An operator should use the weights provided with manifested mail shipments to account for the weight of the mail. If an operator has to separate a shipment of mail, the operator may make actual estimates about the weight of the individual pieces, provided the sum of the estimated weights is equal to the actual manifested weight of the entire shipment.
Note: Operators must ensure when using manifested mail shipments to account for weight, the operator must have procedures to ensure the weights provided are verified.
3.2.4 What are the Standard Average Weights for Special Passenger Groups that Do Not Fit an Operator’s Standard Average Weight Profile?
3.2.4.1 Actual passenger weights should be used for nonstandard weight groups
(e.g., sports teams) unless average weights have been established for such groups by conducting a survey in accordance with the procedures established in paragraph 3.1. When such groups form only a part of the total passenger load, actual weights, or established average weights for the nonstandard group, should be used for such exception groups and average weights used for the balance of the passenger load. In such instances, a notation should be made in the load manifest indicating the number of persons in the special group and identifying the group (e.g., football squad).
3.2.4.2 Roster weights may be used for determining the actual passenger weight.
3.2.4.3 Actual baggage weights must be used in cases where the carry-on bags are not representative of the operator’s profile.
3.2.4.4 Groups that are predominantly male or female should use the standard average weights for males or females provided in Table 3-1.
3.2.4.5 For military groups, the Department of Defense (DOD) requires actual passenger and cargo weights be used in computing the aircraft W&B for all DOD charter missions. This requirement is specified in DOD Commercial Air Carrier Quality and Safety requirements (refer to Title 32 of the Code of Federal Regulations part 861, § 861.4(e)(3)(ix)). FAA-approved air carrier W&B control programs may be used to account for carry-on/personal items for mixed loads of military and their dependents (such as channel missions).
For combat-equipped troop charters, the Air Mobility Command (AMC) will
3-7 provide guidance to account for the additional weight. If aircraft operators perceive that the weights provided are understated, they should seek confirmation of the actual weights and should make reasonable upward estimations and adjustments to those passenger and/or bag weights.
3.3 Average Weights Based on Survey Results.
3.3.1 What Should an Operator Consider when Designing a Survey?
3.3.1.1 This paragraph provides operators with an acceptable survey method to use in determining average weights for a W&B control program. This paragraph also describes how an operator can conduct a survey to count personal items, carry-on bags, and checked bags to determine an appropriate allowance for those items. In addition, an operator may use the methods described in this paragraph to conduct a survey to determine the percentage of male and female passengers and to calculate an average passenger weight.
3.3.1.2 Surveys conducted correctly allow an operator to draw reliable inferences about large populations based on relatively small sample sizes. In designing a survey, an operator should consider:
1. The sample size required to achieve the desired reliability,
2. The sample selection process, and
3. The type of survey (average weights or a count of items).
3.3.2 What Sample Sizes Should an Operator Use? Several factors must be considered when determining an adequate sample size. The more varied the population, the larger the sample size required to obtain a reliable estimate. Paragraph 3.3.3 provides a formula to derive the absolute minimum sample size to achieve a 95 percent confidence level.
Table 3-3, Minimum Sample Sizes, has been provided for those operators that wish to use calculations other than those listed in paragraph 3.3.3. Table 3-3 provides the operator with an acceptable number of samples that may be collected to obtain a 95 percent confidence level and lists the tolerable error associated with each category.
Table 3-3. Minimum Sample Sizes Survey Subject Minimum Sample Size Tolerable Error Adult (standard adult/male/female) 2,700 1% Child 1,400 2% Checked bags 1,400 2% Heavy bag 1,400 2% Planeside loaded bags 1,400 2% Personal items and carry-on bags 1,400 2% Personal items only (for operators with a no carry-on bag program) 1,400 2%
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3.3.3 When Conducting a Survey, Can an Operator Collect a Smaller Sample Size than That Published in Table 3-3? If the operator has chosen to use a sample size that is smaller than that provided in Table 3-3, the operator should collect a sufficient number of samples to satisfy the following formulas:
3.3.4 What Sampling Method Should an Operator Use?
3.3.4.1 Random Sampling. An operator conducting a survey must employ random sampling techniques. Random sampling means that every member of a group has an equal chance of being selected for inclusion in the sample. If an operator conducts a survey that does not employ random sampling, the characteristics of the selected sample may not be indicative of the larger group as a whole. Because of this, any conclusions drawn from such a survey may not be valid.
3.3.4.2 Random Sampling Methods. The following are two examples of random sampling methods that an operator may find appropriate for the type of survey conducted. An operator may also consult a basic publication on statistics to determine whether a different random sampling method is more appropriate.
3.3.4.2.1 Simple Random Selection. An operator should assign a sequential number to each item in a group (such as passengers waiting on a line or bag claim tickets). Then the operator randomly selects numbers and includes the item corresponding with the number in the sample. The operator repeats this process until it has obtained the minimum sample size.
3.3.4.2.2 Systematic Random Selection. An operator should randomly select an item in sequence to begin the process of obtaining samples. The operator should then use a predetermined, systematic process to select the remaining samples
3-9 following the first sample. For example, an operator selects the third person in line to participate in the survey. The operator then selects every fifth person after that to participate in the survey. The operator continues selecting items to include in the sample until it has obtained the minimum sample size.
3.3.4.3 Elective Passenger Participation. Regardless of the sampling method used, an operator has the option of surveying each passenger and bag aboard the aircraft and should give a passenger the right to decline to participate in any passenger or bag weight survey. If a passenger declines to participate, the operator should select the next passenger based on the operator’s random selection method rather than select the next passenger in a line. If a passenger declines to participate, an operator should not attempt to estimate data for inclusion in the survey.
3.3.5 What Should an Operator Consider when Developing a Survey Plan and Submitting it to the FAA?
3.3.5.1 Developing a Survey Plan. Before conducting a survey, an operator should develop a survey plan. The plan should describe the dates, times, and locations the survey will take place. In developing a survey plan, the operator should consider its type of operation, hours of operation, markets served, passenger mix, and frequency of flights on particular routes. In general, an operator should avoid conducting surveys on holidays or other dates that are not representative of normal operations.
3.3.5.2 Submitting the Survey Plan to the FAA. An operator should submit its survey plan to the FAA at least 30 calendar-days before the operator expects to begin the survey. Before the survey begins, the operator’s principal inspector (PI) will review the plan and work with the operator to develop a mutually acceptable plan. During the survey, the PI will oversee the survey process to validate the execution of the survey plan. After the survey is complete, the PI will review the survey results and issue the appropriate OpSpecs or MSpecs. Once a survey begins, the operator should continue the survey until complete, even if the initial survey data indicates that the average weights are lighter or heavier than expected.
3.3.6 What General Survey Procedures Should an Operator Use?
3.3.6.1 Survey Locations. An operator should accomplish a survey at one or more airports that represent at least 15 percent of an operator’s daily departures. To provide connecting passengers with an equal chance of being selected in the survey, an operator should conduct its survey within the secure area of the airport. An operator should select locations to conduct its survey that would provide a sample that is random and representative of its operations. For example, an operator should not conduct a survey at a gate used by shuttle operations unless the operator is conducting a survey specific to that route or the operator only conducts shuttle operations.
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3.3.6.2 Weighing Passengers. An operator that chooses to weigh passengers as part of a survey should take care to protect the privacy of passengers. The scale readout should remain hidden from public view. An operator should ensure that any passenger weight data collected remains confidential.
3.3.6.3 Weighing Bags. When weighing bags, the operator should account for all items taken aboard the aircraft as well as checked-in items. In addition, the operator should ensure a proper accounting for all planeside loaded items, and have procedures on how to handle these items.
Note: The operator should ensure that all scales are certified and calibrated by the manufacturer or a certified laboratory, such as a civil department of weights and measures, or the operator may calibrate the scale under an approved calibration program. The operator should also ensure that the scale is calibrated within the manufacturer’s recommended time, or time periods, as specified in the operator’s approved calibration program.
3.3.6.4 Rounding in Survey Collection. When collecting survey data, values should be recorded to the same precision as the accuracy of the collection method, including considerations such as any calibration tolerance or estimation on analog scales. For example, when using scales calibrated to the nearest pound, it is just as incorrect to record values at the tenth of a pound as it is to round to the nearest 10 pounds.
3.3.6.5 Surveys for Particular Routes. An operator may conduct a survey for a particular route if the operator believes that the average weights on that route may differ from those in the rest of its operations. To establish a standard average passenger weight along the route, an operator may survey passengers at only one location. However, an operator should conduct surveys of personal items and bags at both the departure and arrival locations of the route, unless the operator can substantiate there is no significant difference in the weight and number of bags in either direction along the route.
3.3.7 What Information Might an Operator Gain From Conducting a Count Survey?
An operator may conduct a survey to count certain items without determining the weight of those items. For example, an operator may determine that the standard average weights for male and female passengers are appropriate for its operations, but on some routes, the passengers are predominantly male or female. In such a case, an operator should conduct a survey to determine the percentage of male and female passengers. The operator could use the results of the survey to justify a weight other than the standard weights, which assume a 50 percent male and 50 percent female mix of passengers.
3.3.8 When Should an Operator Conduct Another Survey to Revalidate the Data From an Earlier Survey? In order for survey-derived average weights to be effective, an operator’s W&B control program should include a safety risk assessment and safety management principles from Safety Management Systems (SMS). The operator’s periodic assessment
3-11 should include a method to review its underlying program that considers any survey of passengers or bags. The FAA recommends operators accomplish such a review every 36 calendar-months, as well as when the operator obtains data suggesting a possible change affecting the program. Examples of such changes include the operator changing carry-on bag or checked bag policies, charges for carry-on or checked baggage, and route changes where seasonal variances may not be appropriate. If such an assessment determines that any assumption or behavior has changed, the operator should consider providing notice of a change within 90 days of completing the safety risk assessment and submit mitigating action(s), if necessary. Mitigating actions might include making changes to the program, revalidating survey data, or updating the OpSpecs described in paragraph 4.2.2.
3.3.9 What Standard Average Weights Should an Operator Use for their Baggage Weights?
An operator will use the survey methods described above to determine their standard average baggage weight. Once the operator has completed the survey, the operator will update their OpSpecs with the appropriate weights as well as update their manuals reflecting their standard baggage weights.
3.3.9.1 If an operator chooses not to survey their bags, the operator has the option of using actual weights as described in paragraph 3.4.
3.3.10 What is a Heavy Bag? A heavy bag is considered any bag that weighs more than 50 pounds but less than 100 pounds. An operator should account for a heavy bag by using one of the following weights:
1. An average weight based on the results of a survey of heavy bags, or
2. The actual weight of the heavy bag.
3.3.11 What is a Non-Luggage/Non-Standard Bag? A non-luggage/non-standard bag is any bag that does not meet the normal criteria for luggage or a bag as described in the operator’s W&B program. Examples include golf bags, fishing equipment packages, wheelchairs, strollers in their shipping configuration, windsurfing kits, and boxed bicycles. For non-luggage/non-standard bags, operators may use any appropriate combination of actual weights and average weights based on survey results. Operators that wish to establish an average weight for a particular type of non-luggage/non-standard bag, such as a golf bag, must conduct a survey in accordance with the procedures established in this chapter.
Operators should also establish a method to calculate the effect on CG of a non-luggage/non-standard bag that may occupy more than one compartment on the aircraft.
3.3.12 Planeside Loaded and Checked Bags. Operators using their standard average survey bag weights should consider all bags not stored in the cabin as checked bags. However, operators might develop procedures for identifying bags that would typically be considered carry-on and/or planeside loaded baggage and incorporate such average weights into their approved carry-on and W&B control program. When an operator develops such procedures, the operator may use the standard average weights they determined by survey, specified for carry-on, planeside loaded, and checked baggage.
3-12 Operators conducting flights in which all passenger bags are typically loaded planeside, or all bags are carried into the cabin for further storage, should develop guidelines to inform pilots when it is appropriate to use the heavier standard average checked bag weights, heavy bag weights, or actual weights.
Note: If an operator discovers that a planeside loaded bag should have been treated as a checked bag, the operator should account for that bag at the standard average weight by survey for a checked bag.
3.4 Actual Weight Programs.
3.4.1 If the Operator Decides to Use an Actual Weight Program, How Might it Determine the Actual Weight of Passengers? An operator may determine the actual weight of passengers by:
1. Weighing each passenger on a scale before boarding the aircraft (types of weight scales and scale tolerances will be defined in the operator’s approved W&B control program); or
2. Asking each passenger his or her weight. An operator should add to this asked (volunteered) weight at least 10 pounds to account for clothing. An operator should increase this allowance for clothing on certain routes or during certain seasons, if appropriate.
Note: If an operator believes that the weight volunteered by a passenger is understated, the operator should make a reasonable estimate of the passenger’s actual weight and add 10 pounds.
3.4.2 If the Operator Decides to Use an Actual Weight Program, How Should it Determine the Actual Weights of Personal Items and Bags? To determine the actual weight of a personal item, carry-on bag, checked bag, planeside loaded bag, or a heavy bag, an operator should weigh the item on a scale.
Note: The operator should ensure that all scales are certified and calibrated by the manufacturer or a certified laboratory, such as a civil department of weights and measures, or the operator may calibrate the scale under an approved calibration program. The operator should also ensure that the scale is calibrated within the manufacturer’s recommended time, or time periods, as specified in the operator’s approved calibration program.
3.4.3 What Approach Should an Operator Use to Record Actual Weights? An operator using actual weights should record all weights used in the load calculation.
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.
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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;