12.05 Airframe Structure Flashcards
(28 cards)
The point, usually forward of an aircraft’s nose, from which all dimensions are taken aft, is known as the …?
Datum
Vertical planes perpendicular to an aircraft’s horizontal axis dividing the fuselage from nose to tail are known as …?
Stations
What is Station 0 known as?
The Datum Line
A Vertical plane to the left or right of (and parallel to) the longitudinal axis is known as …?
Buttock or butt lines
Where is Buttock line 0?
Along the Longitudinal axis
Horizontal planes, dividing the aircraft along the vertical axis, are known as …?
Water line
What 2 main classifications are there for aircraft structure?
Primary and secondary
What is the definition of “primary structure”?
The main load-bearing parts of the aircraft
Longitudinal elements of primary helicopter structure would be …?
Stringers and longerons
Vertical elements of primary helicopter structure would be …?
Traverse or cross beams (frames)
Why should a helicopter’s landing gear be directly connected to main frames?
To enable any impact, when landing, to be absorbed by the main structure
What 2 main functions does secondary structure fulfil?
Provide mechanical support for necessary equipment and aerodynamic shape
What is the definition of “tertiary structure”?
Lightly stressed parts, failure of which would not necessarily be serious
What is the function of stringers in a semi monocoque structure?
Absorb bending and shear loads
Designing components so that crack propagation is slow enough to allow monitoring and recording before they become critical is known as …?
Safe Crack Growth
What is the definition of the Safety Concept “Crash Safety”?
In case of an emergency landing, the fuselage should be shock-absorbent to ensure the survival of passengers
What are the 3 common helicopter construction types?
Framework (Lattice),monocoque and semi-monocoque
What is another phrase for “framework design”?
Lattice work
Fuselage construction whereby the skin is of load-bearing construction is …?
Monocoque
The fuselage construction method whereby skin load bearing is supplemented by the internal structure is …?
Semi-monocoque
Stress produced in a body by forces acting along the same line but in opposite directions is …?
Tension
The opposite force to tension is …?
Compression
A twisting force is known as …?
Torsion
Loads created when two material layers move in opposing directions is known as …?
Shear
