Weight and Balance Oral Exam Questions and Answers

October 13, 2026 · Based on FAA-S-ACS-1 and FAA-H-8083-30B, General · Updated October 18, 2026

Weight and balance oral exam questions cover the terms, calculations, weighing procedures and loading limits in General Subject C of the Aviation Mechanic ACS. Prepare to explain what a result means, as well as how you calculated it. The practice questions below are built from ACS elements; they are not actual FAA test questions.

What should a weight and balance answer explain?

A clear answer connects a defined reference point, a calculation and the applicable aircraft limits. Start with the term in the question. If asked about arm, identify the datum before talking about a distance. If asked about a calculated CG, separate the mathematical result from your check of the aircraft limits. Use the question to decide what belongs in the answer; do not recite a complete weighing procedure when only a definition was requested.

The datum is an imaginary vertical reference plane used for aircraft balance measurements. An arm is the horizontal distance from the datum to a point in the aircraft. Moment is weight multiplied by arm, expressed in inch-pounds when weight is in pounds and arm is in inches. Center of gravity is the point at which the aircraft’s weight is concentrated and balanced. Maximum weight is the aircraft’s maximum authorized weight, including its contents, identified in its specifications or TCDS.

FAA-H-8083-30B, General, p. 6-2 · FAA-H-8083-30B, General, p. 6-3

For the wider exam structure, read the A&P oral and practical exam guide. Use the General oral questions overview for the full section, and the ACS codes guide to read the ACS codes on your Airman Knowledge Test Report (AKTR).

Which terms should I distinguish?

Keep these terms separate so your spoken answer describes the right measurement, component or responsibility.

How do weight and arm become a moment?

The FAA’s example of a 5-pound radio at an 80-inch arm produces a 400 inch-pound moment.

FAA-H-8083-30B, General, p. 6-3

Say the units as part of the calculation. Then explain where the item sits relative to the datum. A positive distance is not a statement that the loading is acceptable. Keep the arithmetic, the sign convention and the limits check as separate steps in your explanation.

Which weight and balance oral exam questions can I practice?

The following ten practice questions are built from specific ACS knowledge elements; they are original study prompts rather than advance access to your assigned oral test.

1. What is the datum?

ACS: AM.I.C.K1

The datum is an imaginary vertical reference plane used for aircraft balance measurements. Name the aircraft’s reference before describing measurements from it.

FAA-H-8083-30B, General, p. 6-2

2. What is an arm, and how do you give it a sign?

ACS: AM.I.C.K1

An arm is the horizontal distance from the datum to a point in the aircraft. An arm aft of the datum is positive; an arm forward of it is negative.

FAA-H-8083-30B, General, p. 6-2

3. How do you calculate an item’s moment?

ACS: AM.I.C.K4

Moment is weight multiplied by arm, expressed in inch-pounds when weight is in pounds and arm is in inches. Keep the units consistent throughout the calculation.

FAA-H-8083-30B, General, p. 6-2

4. What does center of gravity describe?

ACS: AM.I.C.K1

Center of gravity is the point at which the aircraft’s weight is concentrated and balanced. State the balance point relative to the datum used for the calculation.

FAA-H-8083-30B, General, p. 6-3

5. How do you calculate CG from a list of weights and moments?

ACS: AM.I.C.K4

CG location is calculated by dividing total moment by total weight. Use the algebraic total moment, keeping the signs of individual entries.

FAA-H-8083-30B, General, p. 6-16

6. What does the maximum weight limit represent?

ACS: AM.I.C.K5

Maximum weight is the aircraft’s maximum authorized weight, including its contents, identified in its specifications or TCDS. Identify the applicable aircraft data before quoting a limit.

FAA-H-8083-30B, General, p. 6-3

7. How do you establish the correct empty-weight configuration?

ACS: AM.I.C.K8

Empty weight includes the airframe, powerplant, required and optional equipment with a fixed location, fixed ballast, hydraulic fluid, and residual fuel and oil. The specifications or TCDS identify the residual fluids and oil condition included in empty weight.

FAA-H-8083-30B, General, p. 6-4

8. Why does the weighing area and aircraft condition matter?

ACS: AM.I.C.K3

Aircraft weighing should take place inside a hangar so wind does not create fluctuating or false scale readings. The aircraft should be clean, with trapped water and debris removed before weighing.

FAA-H-8083-30B, General, p. 6-12

9. What is the purpose of an adverse-loaded CG check?

ACS: AM.I.C.K7

After a weight-and-balance-changing repair or alteration, adverse loading checks establish whether a legal loading condition can put CG outside its limits. Check the loading combinations against the aircraft’s applicable limits.

FAA-H-8083-30B, General, p. 6-20

10. What changes when permanent ballast is installed?

ACS: AM.I.C.K9

Permanent ballast increases empty weight and reduces useful load. The handbook says it should be attached to the structure so it does not interfere with any control action, and rigidly enough that flight maneuvers or a rough landing cannot dislodge it.

FAA-H-8083-30B, General, p. 6-23

How do I answer it out loud?

Use a short answer outline: definition, why it matters, the procedure or check, and the relevant handbook location.

For a calculation question, use this sequence: name the datum, state the weight and signed arm, explain the moment, total the entries, and compare the result with the aircraft data. For a weighing question, describe preparation before discussing the scale reading. Keep the two explanations separate unless the question asks you to connect them.

Begin by answering exactly what was asked. Then add one relevant check or limitation. If you notice that you are listing names without explaining their relationship, stop and restate the function in plain English. Keep the technical term accurate, but do not try to make the sentence sound complicated. This is a study method, not an FAA scoring rule.

Check for an answer that gives a CG number but never says what datum it uses or what limit it must satisfy. Also check whether you silently changed the empty-weight configuration. In your next rehearsal, state those assumptions before calculating. If a value is not provided in a practice scenario, name the document you would consult rather than inventing it.

How should I check my practice answer?

Check the answer against the cited source before rehearsing it again.

Use the radio example from the handbook for a spoken calculation. Explain the 5-pound weight, the 80-inch arm and the resulting moment without reading a finished sentence. Next, keep the same example and ask yourself which sign would apply if the radio were forward of the datum. Finally, stop the calculation and explain what additional aircraft information you would need before making a loading decision.

Use the handbook while reviewing the explanation, then close it for the spoken rehearsal. Reference material is not allowed for answering the oral questions.

“the applicant is not allowed to use any reference material to answer the oral questions asked by the examiner.”

FAA-S-ACS-1, Appendix 1, Applicant Responsibilities.

Keep two notes after each rehearsal: the point you omitted and the source location you will revisit. Rewrite only the part that was missing. On the next attempt, explain the answer in your own words instead of reading the note verbatim. When you cannot resolve a detail from the supplied reference, leave that detail out of the rehearsal until you have checked it. Avoid inventing a value to make the answer feel finished.

Which guide should I read next?

Use the related guides to connect this focused subject with your wider study plan.

• Corrosion Control Oral Exam Questions
• A&P Maintenance Records Oral Exam Questions

Which sources support these answers?

Use the linked primary sources to check the terms, procedures and rules; the FAA handbook references are study references rather than substitutes for aircraft-specific instructions.

• FAA-H-8083-30B, General
• FAA-S-ACS-1, subject AM.I.C and Appendix 1

About this guide: drafted with AI from the FAA sources listed on this page and checked claim by claim against them. Not reviewed by an A&P mechanic or DME. How we make our guides