Conceptual Design Process Questions and Answers

Answer: C

Driving the shape from a small set of variables lets hundreds of configurations be generated and analysed automatically. It is what makes optimisation across the design space practical rather than a matter of drawing each candidate by hand.

Answer: D

Bringing manufacturing and support expertise into the design team early avoids designs that are elegant but impossible to build or maintain economically. It replaces the older sequential approach in which such problems surfaced only after release.

Answer: A

Every part existing in one geometric model allows interference between pipes, wires and structure to be found in software rather than on the assembly line. Maintenance access can also be rehearsed before the first article exists.

Answer: B

It is a gate: the programme demonstrates that the analysis supports the configuration and that the risks are understood, and only then is the large detail-design workforce committed. Passing it prematurely is expensive.

Answer: C

Correct answer: Most of the total, though little is spent

By the end of conceptual design perhaps five per cent of the programme budget has been spent, but the configuration chosen - number of engines, layout, materials, technology level - determines something like two thirds of the lifetime cost of development, manufacture and support. Later phases refine within those choices rather than reopening them. This mismatch between spend and commitment is why so much analytical effort is justified so early, when changes are still nearly free.

Answer: D

Treating thrust as a continuous variable lets the airframe be sized without being constrained by what happens to exist. Fixed-engine sizing, in which an available engine is selected, is the alternative and is more common for derivatives.

Answer: A

Overlaying contours of weight or cost on axes of, say, wing loading and aspect ratio shows where the optimum lies and how flat it is. A flat optimum means the choice can be made on other grounds, which is useful to know.

Answer: B

If relaxing one requirement by five per cent saves ten per cent of the weight while another barely matters, the programme knows exactly where to spend its negotiating effort. Without that knowledge the discussion is merely assertive.

Answer: C

A design that quietly assumes a composite wing, an advanced engine cycle and laminar flow control has stacked three risks that nobody has counted. Recording each assumption and its maturity makes the aggregate risk visible.

Answer: D

Correct answer: A sized configuration and its assumptions

Conceptual design ends with a configuration whose weight, wing area and thrust have been sized to close against the mission, together with the explicit record of what was assumed to get there - the technology levels, the regressions used, the mission profile. The assumptions matter as much as the numbers, because every later phase tests them. Production drawings belong to detail design, and certification is years further on.