Chapter 2 - Airframe Construction Flashcards
What are the forces that a basic fuselage must be able to resist?
Tension Compression Bending Torsion Shear
What requirements are considered with a basic fuselage?
Weight ( as light as possible).
Tail rotor ( has to be outside the rotor disc so it won’t affect the down wash).
To contain the pilot, controls and the payload.
To contain the engine and fuel.
What materials are used in fuselage construction?
Aluminium alloys - duralumin and alclad
Steel alloys
Stainless steel (very good anti corrosive properties)
Titanium alloys (3x stronger than steel)
What are the advantages of aluminium alloys?
High strength to weight ratio A wide range of different alloys Low density Available in many forms Easy to work with after being heated
What are the disadvantages of aluminium alloys?
Prone to corrosion
Limited strength especially at elevated temperatures
What are the advantages of steel?
Cheap and readily Available
Consistent strength
High strength
Stainless steel can be highly resistant to corrosion
High tensile steels have high strength to weight ratio
Hard surface is resistant to wear
Most steels are easily joined by welding
What are the disadvantages of steel?
Poor strength to weight ratio except high tensile alloys
Most steels are prone to corrosion
Dense, so care must be taken out to use very thin sections or buckling may result
What is a composite?
A composite consists of two materials bonded together in such a way that the best strength characteristic of one compliments the other.
What are the main composites used in military aviation?
Glass reinforced plastic (GRP)
Carbon reinforced plastics (CRP)
Aramid fibre
What are the main constructional areas of a helicopter airframe?
Forward structure (accommodate the aircrew) Centre structure (consisting of the lower and rear) Rear structure (to position and support the tail rotor and support the driveshaft)
What are the structural components of a military aircraft?
Frames/formers Floors Longerons Panels Stringers Fairings Beams Skin Bulkheads
What are the three types of bulkheads?
Structural, fuel tank and fireproof.
What are the 3 types of quick release fasteners?
Dzus fastener
Oddie fastener
Camloc fastener
What are the six types of airframe rotor design?
Single main rotor Tandem main rotor Tilt twin main rotor Dual main rotor Tilting rotor NOTAR
