Conceptual Design Process Questions and Answers

Answer: C

Correct answer: Both A and R are true, and R is the correct explanation of A

Both are true and the reason explains the shift. Conceptual design surveys many configurations at low fidelity to choose one; preliminary design takes that choice as settled and spends its effort deepening it - structural layout, systems architecture, wind tunnel testing, refined weights. The number of configurations falls while the fidelity rises, and by detail design only one remains.

Answer: D

Both are true and the second explains the first. Approving a configuration that cannot meet its requirements sets hundreds of people to work on the wrong aircraft, which is why the evidence is examined rather than merely presented.

Answer: A

Both statements are true and the second is the reason for the first. Where the engine is fixed, the airframe must be sized around its thrust rather than the other way about, which changes the whole character of the sizing exercise.

Answer: B

Correct answer: 1 and 2 only

Statements 1 and 2 describe the first two phases correctly. Statement 3 inverts the trend: detail design works on a single configuration, defining every part and producing the data to manufacture it. The number of configurations falls steadily through the phases while the fidelity of the analysis rises, which is the fundamental shape of the whole process.

Answer: C

Correct answer: 1 and 2 only

Statements 1 and 2 are correct: the loop iterates because weight and fuel each depend on the other, and convergence means a self-consistent design has been found. Statement 3 is wrong and is a dangerous misreading. Divergence is usually a real physical result - the mission exceeds what the assumed technology can achieve - and treating it as an arithmetic error wastes time that should be spent renegotiating the requirement.

Answer: D

Correct answer: 1 and 2 only

Statements 1 and 2 are correct: regressions give a fast first estimate and must be drawn from the right class of aircraft. Statement 3 is their central weakness. A regression describes the aircraft it was fitted to and nothing more, so it cannot be trusted for a blended wing body, a strut-braced wing or any configuration outside its sample. Novel designs need physics-based estimates much earlier for that reason.

Answer: A

Correct answer: 1 and 2 only

Statements 1 and 2 define what multidisciplinary optimisation is for. Statement 3 is the opposite of the truth: coupling the disciplines means evaluating the whole system at every step, so it is very much more expensive than optimising one discipline at a time. The cost is accepted because the interactions dominate the result, and surrogate models exist largely to make it affordable.

Answer: B

The first two are correct and together make the case for investing in early design. The third follows the money rather than the leverage: by detail design most of the cost is already committed and little remains genuinely open.

Answer: C

The first two are correct. The third is emphatically false: configuration choices propagate into structure, systems and tooling, and reversing one after detail design has begun is among the most expensive changes a programme can make.

Answer: D

The first two are correct. The third misunderstands its function: the review is a gate at which evidence is examined, and treating it as a presentation is how programmes commit large workforces to configurations that cannot close.