Conceptual Design Process Questions and Answers

Answer: A

Correct answer: 1 and 2 only

Statements 1 and 2 are correct: readiness levels should be recorded, and immature technologies compound each other’s risk. Statement 3 is too absolute. A single low-readiness technology may be entirely acceptable where the payoff is large, the maturation is funded and a fallback exists. The purpose of recording readiness is to make that judgement deliberate, not to forbid risk.

Answer: B

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

Each phase has a characteristic deliverable. Conceptual design produces a sized configuration and the assumptions behind it. Preliminary design produces a refined configuration with structure and systems defined and the major uncertainties tested. Detail design produces the drawings and data sufficient to manufacture. Certification produces the evidence that the aircraft meets its requirements.

Answer: C

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

Historical regression gives the rapid first weight estimate. The sizing loop resolves the circular dependence between weight and fuel by iteration. A carpet plot displays how a figure of merit varies over two design variables at once, which is how a flat or sharp optimum is recognised. A parametric geometry model generates the many configurations that exploration requires from a few driving variables.

Answer: D

Every configuration choice answers a specific problem and brings its own penalties, and the layout that results is a negotiated settlement rather than an optimum. Recognising the motivation behind each is how an unfamiliar aircraft is read.

Answer: A

The loop is diagnostic as well as computational: how it behaves says something about whether the requirements are achievable at all. A design that will not close is telling the programme something it needs to hear early.

Answer: B

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

Concurrent engineering brings manufacturing and support into the design team so that unbuildable or unmaintainable designs are caught while they can still be changed. A digital mock-up finds clashes and access problems that would otherwise appear at first assembly. A design review gate prevents a large workforce being committed to an unproven configuration. Recording technology readiness prevents the silent accumulation of immature technology risk.

Answer: C

Drawings belong to detail design, by which time the configuration has long been settled. Conceptual design deliberately trades precision for breadth, since choosing the right configuration matters more than analysing any one of them accurately.

Answer: D

Correct answer: The analysis software is unreliable

The loop iterates for a structural reason, not a computational one. Fuel weight depends on total weight, total weight includes the fuel, and empty weight scales with take-off weight - three statements that together make the sizing equation implicit in its own unknown. It would iterate identically with perfectly reliable software, or with pencil and paper, because the circularity is in the physics.

Answer: A

Correct answer: They extrapolate reliably beyond the aircraft they were fitted to

This is the incorrect statement. A regression is an interpolation within its sample and carries no authority outside it; applied to a configuration unlike anything in the data it can be badly wrong in either direction. The other three are true - regressions are fast, they must be matched to the class, and they give way to physics-based methods once the design is defined well enough to support them.

Answer: B

Correct answer: The design is insensitive to every variable

A flat optimum says something about one variable, or a pair of them on a carpet plot, and nothing whatever about the rest - the design may be acutely sensitive to wing loading while being indifferent to aspect ratio. The other three do follow: precision in that variable is not critical, and it may therefore be chosen on grounds the figure of merit does not capture.