Design Stages

Question 1

Four stages of the design wheel

Answer 1

Requirements -> Design concept -> Design analysis -> Sizing and trade-off studies

Question 2

List and give examples of the 4 main requirement types.

Answer 2

• Top-level requirements (purpose and operation, cost)
• Customer-centric requirements (performance capabilities)
• Legalistic requirements (stall speed, reverse fuel)
• Company requirements (handbooks)

Question 3

3 phases of aircraft design

Answer 3

1. Conceptual Design (requirements, weight, look)
2. Preliminary Design (freeze configuration and develop)
3. Detail Design (actual design of parts and testing)

Question 4

Describe the conceptual design stage

Answer 4

• Look at wide range of aircraft concepts before settling on best design.
• At the end of this stage, major design changes (e.g aircraft configurations) should be over.
• If CAD is used, should enable rapid and continuous design revision.
• Approx 6 months

Question 5

Describe the preliminary design stage.

Answer 5

• Specialists will design and analyse their own portions and systems of the aircraft.
• CAD mock-up
• At the end of this phase, overall design arrangement is frozen.
• CFD, FEA, wind tunnel testing.
• Up to 2 years

Question 6

Describe the detail design process.

Answer 6

• Actual parts get designed (landing gear, hydraulics, control surfaces etc.)
• No. of parts = several thousand to several million
• Hundreds or thousands of staff required.
• CAD drawings of each part and assembly.