Weight Estimation Methods Questions and Answers

Answer: A

Correct answer: 1 and 2 only

Statements 1 and 2 are correct: mass properties comprise mass, centre of gravity and the moments and products of inertia, and the inertias feed handling qualities and flutter analysis. Statement 3 is false, and would make aircraft design impossible - inertias are calculated from the mass distribution long before anything exists to swing, and measurement on the finished article is a check rather than the source.

Answer: B

Correct answer: A-2, B-1, C-4, D-3

Four definitions that differ in what they include. Manufacturer’s empty weight is the aircraft as built, without operational items. Operating empty weight adds crew, oil, catering and unusable fluids to give the aircraft ready for service. Zero fuel weight adds the payload but no usable fuel. Maximum landing weight is not a build state at all but a structural limit on touchdown.

Answer: C

Fidelity rises through the sequence as the design firms up, and each level costs more effort than the last. Using a high-fidelity method before the design supports it wastes work on a configuration that may not survive.

Answer: D

Correct answer: A-2, B-1, C-4, D-3

Each group is driven by what actually loads it. The wing carries bending, so its weight follows area, aspect ratio and design load factor. The fuselage is a pressure vessel, so wetted area and pressure differential drive it. The undercarriage absorbs the landing, so landing weight and sink rate. Furnishings scale with what the cabin holds - configuration and seat count.

Answer: A

Correct answer: A-2, B-1, C-4, D-3

The two limits are set by different things, which is the point of the question. The forward limit is a control limit: enough elevator power to rotate and flare. The aft limit is a stability limit: the static margin must not fall so far that the aircraft becomes over-sensitive. In-flight movement comes from fuel burn sequence and passenger distribution, and everything is quoted against the mean aerodynamic chord.

Answer: B

Correct answer: A-2, B-1, C-4, D-3

Each activity answers a different question. Allocating group weights makes each design group accountable for its share. The regular statement shows the trend so growth is visible early. The loading diagram demonstrates that permitted loadings stay inside the envelope. And the mass properties calculation supplies the inertias that handling and flutter work need.

Answer: C

Correct answer: Usable fuel

Operating empty weight is the aircraft ready for service but empty of revenue load and of fuel: it includes the flight and cabin crew, engine oil, catering equipment, emergency equipment and unusable fluids. Usable fuel is added on top, which is why zero fuel weight, take-off weight and operating empty weight form a ladder with fuel and payload as the rungs.

Answer: D

Correct answer: The fuel tanks would overflow

Maximum zero fuel weight is a structural limit on wing root bending. Payload in the fuselage adds to that moment while fuel in the wing relieves it, so the worst case is maximum payload with minimum fuel - which is exactly the zero fuel condition. Tank capacity is a separate physical limit and has nothing to do with why the zero fuel weight is capped.

Answer: A

Correct answer: Class III uses historical fractions

Class III is the class that stops using history. It analyses the actual defined parts - their geometry, material and joints - which is why it is the most accurate and the most expensive of the three. The other three statements are all correct: Class I works at aircraft level, Class II uses group statistical formulae, and fidelity rises through the classes.

Answer: B

Correct answer: Adding load at the current centre of gravity

A load placed exactly at the centre of gravity has zero arm, so it adds no moment; the total weight rises but the centre of gravity stays put. Every other option places weight at a distance from it - forward hold, aft tank, front cabin - and so shifts it, forward or aft according to where the weight is added or removed.