Chap1

What is the purpose of the wing main spar?

• To withstand bending and torsional loads

• To withstand compressive and torsional loads

• To withstand compressive and shear loads

• To withstand bending and shear loads

What is the purpose of wing ribs?

• To withstand the fatigue stresses

• To shape the wing and support the skin

• To house the fuel and the landing gear

• To provide local support for the skin

What is the purpose of stringers?

• To absorb the torsional and compressive stresses

• To produce stress risers and support the fatigue metres

• To prevent buckling and bending by supporting and stiffening the skin

• To support the primary control surfaces

The airframe structure must remain substantially intact after experiencing:

• the design ultimate load times a 1.5 safety factor

• the design limit load plus the design ultimate load

• three times the safety factor

• the design limit load times a 1.5 factor of safety

In the construction of airframes the primary purpose of frames or formers is to:

• provide a means of attaching the stringers and skin panels

• oppose hoop stresses and provide shape and form to the fuselage

• form the entrance door posts

• support the wings

How can wing bending moments be reduced in flight?

• By using aileron 'up-float' and keeping the centresection fuel tanks full for as long as possible

• By using aileron 'up-float' and using the fuel in the wings last

• By having tail-mounted engines and using aileron 'down-float'

• By having wing-mounted engines and using the wing fuel first

Regarding a safe life structure: 1. will only fail after a known number of operations or hours of use. 2. should not fail until a predicted number of fatigue cycles has been achieved. 3. has a programmed inspection cycle to detect and rectify faults. 4. is changed before its predicted life is reached.

• 1 and 2 apply

• 1 and 3 apply

• 2, 3 and 4 apply

• all of the above apply

A fail-safe structure: 1. has a programmed inspection cycle to detect and rectify faults; 2. is changed before its predicted life is reached; 3. has redundant strength which will tolerate a certain amount of structural damage; 4. is secondary structure of no structural significance.

• 1 and 2 apply

• 1 and 3 apply

• 3 and 4 apply

• all of the above apply

The skin of a modern pressurized aircraft:

• is made up of light alloy steel sheets built on the monocoque principle

• houses the crew and the payload

• provides aerodynamic lift and prevents corrosion by keeping out adverse weather

• is primary load bearing structure carrying much of the structural loads

The primary purpose of the fuselage is to:

• support the wings

• house the crew and payload

• keep out adverse weather

• provide access to the cockpit