EWCG range and adverse-loading checks

Aviation Mechanic General (AMG) practice question 17 of 25 on Weight and Balance. ACS element AM.I.C.K6 · difficulty: standard. Want to answer it in a timed quiz? Use the Aviation Mechanic General (AMG) practice mode.

Question bank updated 2026-09-22

QUESTIONAfter an alteration, a mechanic finds that the aircraft's new EWCG falls within the empty weight CG range listed in the TCDS. What does this mean for the adverse-loading check?

AOnly the aft adverse-loading check still has to be computed
BNo forward or aft adverse-loading check needs to be computed
CBoth checks must still be computed because the EWCG range is only advisory

Show the answer and explanation

Correct answer: B. No forward or aft adverse-loading check needs to be computed

A — incorrect When the EWCG is inside the listed range, it is impossible to legally load the aircraft out of limits in either direction, so neither check is required.
B — correct The handbook states that if the TCDS lists an EWCG range and the EWCG falls within it after a repair or alteration, there is no need to compute a fore and aft check for adverse loading.
C — incorrect The EWCG range is a certification value; falling within it removes the need for adverse-loading checks rather than being advisory.

BACKGROUND

For some aircraft the TCDS gives a CG range for the empty weight condition. This is uncommon for airplanes but often done for helicopters, and is listed for an airplane only when the fuel tanks, seats, and baggage compartments are located so that load changes have a very limited effect on balance. If the EWCG falls within the EWCG limits, it is impossible to legally load the aircraft so that its loaded CG falls outside its allowable range, so no fore and aft adverse-loading check is needed. If the TCDS lists the EWCG range as None, which most do, forward and aft adverse-loaded CG checks must be performed and the results noted in the weight and balance revision sheet.

STUDY TIP

Check the TCDS first: an EWCG range that contains the new EWCG ends the adverse-loading work; a range of None means both checks are required.

KEY POINTS

Some TCDS list an empty weight CG range.
EWCG inside that range means no adverse-loading checks are needed.
EWCG range of None requires forward and aft checks.

SOURCES

FAA-H-8083-30B ch06 "Empty Weight Center of Gravity (EWCG) Range"
FAA-H-8083-30B ch06 "Adverse-Loaded CG Checks"

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