AC 120-27D

AC 120-27D DATE: 8/11/04 Initiated By: AFS-200/ AFS-300

ADVISORY CIRCULAR

AIRCRAFT WEIGHT

AND BALANCE CONTROL

U.S. DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Flight Standards Service Washington, D.C.

TABLE OF CONTENTS Paragraph Page

CHAPTER 1. INTRODUCTION1

100. What is the purpose of this advisory circular (AC)?1

101. How is this AC organized?1

102. What documents does this AC cancel?1

103. What should an operator consider while reading this AC?2

104. Who should use this AC?2

Table 1-1. Aircraft Cabin Size2

105. Who can use standard average or segmented weights?2

CHAPTER 2. AIRCRAFT WEIGHTS AND LOADING SCHEDULES5

Section 1. Establishing Aircraft Weight5

200. How does an operator establish the initial weight of an aircraft?5

201. How does an operator document changes to an aircraft’s weight and balance?5

Table 2-1. Incremental Weight Changes that Should Be Recorded in a Weight and

Balance Change Record5

202. How does the operator maintain the OEW?6

203. How often are aircraft weighed?6

Table 2-2. Number of Aircraft to Weigh in a Fleet7

204. What procedures should be used to weigh aircraft?7

Section 2. Aircraft Loading Schedules9

205. What is a loading schedule?9

206. How should an operator determine the weight of each fluid used aboard

the aircraft?10

Section 3. Constructing a Loading Envelope11

207. What should an operator consider when constructing a loading envelope?11

208. What information from the aircraft manufacturer should an operator use?11

209. What should the operator consider when curtailing the manufacturer’s loading

envelope?11

210. What are some examples of common curtailments to the manufacturer’s loading

envelope?12

Section 4. Automated Weight and Balance Systems15

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211. How does an onboard weight and balance system compare to a conventional

weight buildup method?15

212. What measures should an operator take to obtain operational approval for

an onboard weight and balance system?15

213. What operational considerations should an operator take into account when

using an onboard weight and balance system?16

214. May an operator use the information in this AC to develop a backup system?17

215. What operational considerations should an operator take into account when

using a computerized weight and balance system?17

CHAPTER 3. METHODS TO DETERMINE THE WEIGHT OF PASSENGERS

AND BAGS19

Section 1. Choosing the Appropriate Method19

300. What should an operator consider when choosing the appropriate method?19

Section 2. Standard Average Weights21

301. What standard average passenger weights should an operator with an approved

carry-on bag program use?21

Table 3-1. Standard Average Passenger Weights21

302. What standard average weights should an operator use for carry-on bags

and personal items?22

303. What standard average weights should an operator use for checked bags?22

304. What standard average weight should an operator of large cabin aircraft use

for bags checked plane-side?23

305. What standard average weights should an operator of small and medium cabin

aircraft use, if it has a “no-carry-on bag program?”23

Table 3-2. Average Passenger Weights for Operators with a No-Carry-on Bag Program ...24

306. What are the standard average weights for crewmembers?24

Table 3-3. Standard Crewmember Weights24

307. What weights may be used for company materials and mail?25

308. What are the standard average weights for special passenger groups that do

not fit an operator’s standard average weight profile?25

Section 3. Average Weights Based on Survey Results27

309. What should an operator consider when designing a survey?27

310. What sample sizes should an operator use?27

Table 3-4. Minimum Sample Sizes27

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311. When conducting a survey, can an operator collect a smaller sample size than

that published in Table 3-4?28

312. What sampling method should an operator use?28

313. What should an operator consider when developing a survey plan and submitting

it to the FAA?29

314. What general survey procedures should an operator use?29

315. What information might an operator gain from conducting a count survey?30

316. When should an operator conduct another survey to revalidate the data from

an earlier survey?31

Section 4. Segmented Passenger Weights32

317. What should an operator consider when using segmented weights?32

Table 3-5. Segmented Weights for Adult Passengers (in Pounds; Summer)32

318. How are loading envelope curtailment and bag weight affected by an

operator’s use of segmented weights?32

319. What might be an example be of an operator using the segmented weights in

Table 3-5?33

Section 5. Actual Weight Programs34

320. If the operator decides to use an actual weights program, how might it

determine the actual weight of passengers?34

321. If the operator decides to use an actual weight program, how should it

determine the actual weights of personal items and bags?34

322. What approach should an operator use to record actual weights?34

CHAPTER 4. OPERATOR REPORTING SYSTEMS AND FAA OVERSIGHT35

Section 1. Pilot and Agent Reporting Systems35

400. What are the pilots’ and operators’ responsibilities in reporting aircraft

loading and manifest preparation discrepancies?35

Section 2. FAA Oversight36

401. Which FAA inspectors are responsible for overseeing an operator’s weight and

balance program?36

402. Which portions of OpSpecs or MSpecs are relevant to an operator’s weight and

balance program?36

403. When will the FAA revise the standard average weights in this AC?38

APPENDIX 1. DEFINITIONS (4 pages)1

APPENDIX 2. SOURCE OF STANDARD AVERAGE WEIGHTS IN THIS AC (1 page)..1 Page iii

1. Standard average passenger weights1

2. Standard average bag weights1

Table 2-1. Bag Survey Results1

APPENDIX 3. SAMPLE OPERATIONAL LOADING ENVELOPE (8 pages)1

1. Introduction1

2. Assumptions for this example1

Figure 3-1. Sample Aircraft Interior Seating Diagram1

3. Curtailments for passenger seating variation2

Table 3-1. Calculation of Zone 1 Centroid2

Table 3-2. Calculation of Zone 2 Centroid2

Table 3-3. Calculation of Zone 3 Centroid2

Table 3-4. Moments Resulting from the Zone Centroid Assumption for Zone 13

Table 3-5. Moments Resulting from the Window-Aisle-Remaining Assumption

for Zone 13

Table 3-6. Comparison of Moments for Zone 13

Table 3-7. Moments Resulting from the Zone Centroid Assumption for Zone 24

Table 3-8. Moments Resulting from the Window-Aisle-Remaining Assumption

for Zone 24

Table 3-9. Comparison of Moments for Zone 24

Table 3-10. Moments Resulting from the Zone Centroid Assumption for Zone 35

Table 3-11. Moments Resulting from the Window-Aisle-Remaining Assumption

for Zone 35

Table 3-12. Comparison of Moments for Zone 35

4. Other curtailments to the manufacturer’s loading envelope6

5. Operational loading envelope diagrams7

Figure 3-2. Operational Loading Envelope with a Curtailment for Variations

in Passenger Seating7

Figure 3-3. Operational Loading Envelope Using Actual Seating Location

of Passengers8

APPENDIX 4. ADDITIONAL CURTAILMENTS TO CG ENVELOPES TO

ACCOUNT FOR VARIATIONS TO PASSENGER WEIGHTS (3 pages)1

Table 4-1. Row Factor1

Table 4-2. Sample Curtailment Due to Variations in Passenger Weight and

Male/Female Ratio Using Window-Aisle Method1

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APPENDIX 5. OPTIONS TO IMPROVE ACCURACY (7 pages)1

Figure 5-1. Sample Aircraft Interior Seating Diagram2

Figure 5-2. Sample Passenger Seating Moment4

Figure 5-3. Sample Passenger Seating Moment5

Figure 5-4. Sample Passenger Seating Moment6

APPENDIX 6. SAMPLE CG ENVELOPE DEVELOPMENT (4 pages)1

Figure 6-1. Operational CG Envelope3 Passenger Cabin Zones3

Figure 6-2. Operational CG EnvelopeActual Passenger Seating4

APPENDIX 7. CHECKLIST (3 pages)1

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CHAPTER 1. INTRODUCTION

100. What is the purpose of this advisory circular (AC)?

a. This AC provides operators with guidance on how to develop and receive approval for a weight and balance control program for aircraft operated under Title 14 of the Code of Federal Regulations (14 CFR) part 91, subpart K of part 91, and parts 121, 125, and 135.

b. This AC presents recommendations for an acceptable means, but not the only means, to develop and receive approval for a weight and balance control program, and includes guidance for using average and estimated weights in accordance with part 121, section 121.153(b) and other applicable parts of subpart K of part 91 and parts 121, 125, and 135.

NOTE: Per part 125, section 125.91(b), no person may operate an airplane in a part 125 operation unless the current empty weight and center of gravity (CG) are calculated from the values established by actual weighing of the airplane within the preceding 36 calendar-months.

c. If an operator adopts the suggestions contained in this AC, the operator must ensure that, when appropriate, it replaces discretionary language such as “should” and “may” with mandatory language in relevant manuals, operations specifications (OpSpecs), or management specifications (MSpecs).

101. How is this AC organized?

This AC has four main chapters and seven appendixes. Chapter 1 contains general information about this AC and background. Chapter 2 addresses aircraft weighing and loading schedules.

Chapter 3 describes different methods to determine the weight of passengers and bags.

Chapter 4 addresses the Federal Aviation Administration’s (FAA) role in developing and approving an operator’s weight and balance control program. Finally, appendixes 1 through 7 contain technical information such as definitions, the source of data used in the AC, a sample loading envelope, an example of curtailments to the loading envelope, suggestions to improve accuracy, sample CG envelope development, and checklists for operators.

102. What documents does this AC cancel?

This AC cancels—

a. AC 120-27C, Aircraft Weight and Balance Control, dated November 7, 1995; and

b. Joint Handbook Bulletin for Airworthiness (HBAW) 95-14 and Air Transportation (HBAT) 95-15, Adherence to Advisory Circular 120-27C, “Aircraft Weight and Balance Control,” dated November 17, 1995.

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103. What should an operator consider while reading this AC?

a. Accurately calculating an aircraft’s weight and CG before flight is essential to comply with the certification limits established for the aircraft. These limits include both weight and CG limits. By complying with these limits and operating under the procedures established by the manufacturer, an operator is able to meet the weight and balance requirements specified in the aircraft flight manual (AFM). Typically, an operator calculates takeoff weight by adding the operational empty weight (OEW) of the aircraft, the weight of the passenger and cargo payload, and the weight of fuel. The objective is to calculate the takeoff weight and CG of an aircraft as accurately as possible.

b. When using average weights for passengers and bags, the operator must be vigilant to ensure that the weight and balance control program reflects the reality of aircraft loading. The FAA will periodically review the guidance in this AC and update this AC if average weights of the traveling public should change or if regulatory requirements for carry-on bags or personal items should change. Ultimately, the operator is responsible for determining if the procedures described in this AC are appropriate for use in its type of operation.

104. Who should use this AC?

a. This document provides guidance to operators that are either required to have an approved weight and balance control program under parts 121 and 125, or choose to use average aircraft, passenger or baggage weights when operating under subpart K of part 91 or part 135. The guidance in this AC is useful for anyone involved in developing or implementing a weight and balance control program.

b. As shown in Table 1-1, the FAA has divided aircraft into three categories for this AC to provide guidance appropriate to the size of the aircraft.

TABLE 1-1. AIRCRAFT CABIN SIZE For this AC, an aircraft originally type-certificated with— Is considered— 71 or more passenger seats A large-cabin aircraft.

30 to 70 passenger seats A medium-cabin aircraft.

5 to 29 passenger seats A small-cabin aircraft.

0 to 4 passenger seats Not eligible.

105. Who can use standard average or segmented weights?

a. Standard Average Weights. Use of standard average weights is limited to operators of multiengine turbine-powered aircraft originally type-certificated for five (5) or more passenger seats who hold a letter of authorization (LOA), OpSpecs, or MSpecs, as applicable, and were certificated under 14 CFR part 25, 29, or part 23 commuter category or the operator and manufacturer is able to prove that the aircraft can meet the performance requirements of subpart B of part 25. Single-engine and multiengine turbine Emergency Medical Service Helicopter (EMS/H) operators may use standard average weights for EMS operations, provided they have received an LOA.

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b. Segmented Weights. Use of segmented weights is limited to those aircraft that meet the requirements of paragraph 105(a) or that are multiengine turbine-powered aircraft originally type-certificated for five (5) or more passenger seats and that do not meet the performance requirements of subpart B of part 25. Segmented passenger weights are listed in Chapter 3, Table 3-5.

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