Weight Estimation Methods Questions and Answers

Answer: C

The fuselage is essentially a pressure vessel and a beam, so its surface area and the loads along its length govern. Cabin pressure differential adds directly, which is why unpressurised aircraft have notably lighter fuselages.

Answer: D

It is a small but stubborn fraction, and it scales with landing weight and with the sink rate the gear must absorb. Because the gear is carried throughout every flight for use in only a few seconds, it is a persistent target for weight reduction.

Answer: A

Quoting a centre of gravity at twenty-five per cent of mean aerodynamic chord means the same thing whatever the aircraft's size, so limits and margins can be compared directly. It is the chord of an equivalent rectangular wing with the same moment behaviour.

Answer: B

Correct answer: Moments about a datum, over total weight

Every item contributes a moment equal to its weight times its arm from an arbitrary datum, and the centre of gravity is the sum of those moments divided by the total weight. The datum is arbitrary because it cancels; what matters is that every arm is measured from the same one. Averaging component positions ignores their weights and gives the wrong answer whenever they differ.

Answer: C

A very forward centre of gravity makes the aircraft strongly stable but leaves too little elevator power to raise the nose. The aft limit is set instead by stability and by control sensitivity, so the usable envelope lies between them.

Answer: D

As the centre of gravity moves aft the static margin falls, and beyond a point the aircraft becomes unacceptably sensitive or unstable. Relaxed stability designs deliberately go beyond the classical limit and restore handling artificially.

Answer: A

Passengers boarding front to rear, cargo in one hold rather than another and fuel burning in sequence all move the centre of gravity, and the diagram demonstrates that no permitted combination takes it outside the envelope.

Answer: B

Emptying an outboard tank before an inboard one shifts the balance, and long-range aircraft sometimes use a tail tank deliberately to trim the aircraft aft in cruise and reduce trim drag. The schedule is designed with the envelope in mind.

Answer: C

Moments of inertia govern how quickly the aircraft responds in roll, pitch and yaw, and they are needed for handling qualities and flutter analysis. They are computed from the same itemised data as the centre of gravity.

Answer: D

Each design group receives a budget and reports against it regularly, so growth is visible while there is still time to act. Programmes that track only the aircraft-level figure discover the problem when the first article is weighed.