11.2 Instructor Q Flashcards
What are the principle structural elements of the aircraft?
The take on aerodynamic forces and stresses of flight, ground and pressurisation loads
What is the relationship between ultimate load limit, limit load and factor of safety?
Limit load X factor of safety = ultimate limit load
When beam like spars or other components subjected to bending moments what forces occur?
Tension on the outside of the bend and compression on the inside of the bend
What is safe life design?
A set time where a component should not fail
What is fail safe design?
Every component has a duplicate so if one fails it does not cause catastrophic failure
What is the problem of fail safe design?
It increases weight
What is damage tolerance?
Through multiple part design an allowable amount of damage can occur
What is primary structure and examples of primary structure?
Critical load bearing structures
-wing spars
-fuselage
-frames
-floors
What is secondary structure and examples of secondary structural parts?
All non primary structures which posses intrinsic structural significance
-wings
-ribs
-fuselage
-stringers
What is tertiary structure and examples of tertiary structural parts?
Lightly stressed structures
What stresses are applied to aircraft fuselage when it is pressurised?
Hoop stress to the skin and axial force on bulkheads
What are the numbers associated with the following major zones?
-upper half of the fuselage
-power plants and the struts
-right wing
-landing gear and the landing gear doors
-200
-400
-600
-700
How are access panels in a particular zone identified?
Two suffix letters
-sequence
-location
What is a body station?
The body station or fuselage station is a vertical plane at a right angle to the body centreline
How is the body station line measured?
From the nose or a point in front of the nose
What are buttock lines?
The body buttock line or butt lines are vertical planes parallel to the body (fuselage) centreline plane.
What is a waterline?
The body waterlines are horizontal planes at a right angle to the body stations and the body buttock lines.
How are wing stations defined?
The wing reference plane or wing stations extend left and right and are measured in either inches or millimetres from either a butt line reference point or from wing rib 1. The horizontal and vertical stabiliser coordinates are equal to the wing coordinates.
What prevents fluid build up in the lower fuselage?
Bilge like valves
Which areas aircraft are most likely to be hit by lightning?
-engine nacelle
-horizontal stabiliser
-radome
-Trailing edge discharge wicks
What does bonding in the aircraft system provide?
Maintain the same potential difference across the airframe
What provides surface protection for aluminium alloys?
Pre treatment and paint
What are the functions of fuselage frames and stringers?
To give shape and structure and attachment points for structures
What are the structural components for a wing?
Spars, skin, ribs and stringers
