Metallic Aircraft Structures Flashcards
Define true monocoque:
A structure with bulkheads and formers for shape but ALL flight loads are carried in the sheet metal skin.
Define semi-monocoque:
A structure in which MOST of the strength is in the skin, but the skin is supported on a substructure of formers and stringers.
4 main structural components that form the shape of and provide rigidity to the skin of the aircraft.
Bulkhead
Longeron
Stringer
Former
The maximum amount of tensile load a material can withstand without being permanently deformed:
Elastic limit
5 basic stresses:
Tensile
Torsion
Sheer
Compression
Bending
Alloy type 1xxx =
Aluminum
Alloy type 2xxx =
Copper
Alloy type 3xxx =
Manganese
Alloy type 4xxx =
Silicon
Alloy type 5xxx =
Magnesium
Alloy type 6xxx =
Magnesium and silicon
Alloy type 7xxx =
Zinc
Aluminum alloy temper designation “F” =
The metal has been left as fabricated.
Aluminum alloy temper designation “T” =
The metal may be heat treated.
Aluminum alloy temper designation “H” =
Cannot be heat treated but can be hardened by cold working.
Aluminum alloy temper designation “O” =
Metal has been annealed.
4 different heat treatment processes:
Solution heat treatment.
Aging.
Precipitation heat treatment.
Annealing.
Annealing does what to the aluminum alloy?
Makes it soft, but also weak.
Strength of the rivet is called _____.
Sheer strength.
Strength of the riveted sheet metal is called ______.
Bearing strength.
T/F
Clad aluminum alloy is stronger than unclad.
False.
Clad is weaker.
Shortcomings of magnesium alloys:
Susceptibles to corrosion.
Brittle.
Flammable.
Rivet 470 =
Universal head
Rivet 426 =
Countersunk head.
Rivet 430 =
Round head.
Rivet 442 =
Flat head.
Icebox rivets are made of which two alloys?
2017
2024
Rivet with raised dot =
2017T
Field code - D
Icebox
Rivet with raised double dash
2024T
Icebox
Field code - DD
Rivet with recessed dot =
2117T
Field code - AD
Rivet with raised cross =
High magnesium
5056H
Field code - B
AD =
2117T
Recessed dot
A =
1100
Plain (no marking)
D =
Icebox
2017T
Raised dot
DD =
Icebox
Raised double dash
2024T
B =
High magnesium
5056H
Raised cross.
A fastener that provides a threaded hole in a piece of thin sheet metal:
Rivnut
List the cleco colors and their corresponding rivet sizes.
Silver - 3/32
Copper - 4/32
Black - 5/32
Brass - 6/32
Copper - 8/32
Rivet diameter =
3x thickness of the thickest sheet being joined.
Edge distance tolerance =
2x - 4x diameter
Rivet pitch tolerance =
3 - 12x diameter
Transverse pitch =
Same as pitch if even rows.
75% of pitch if staggered rows.
Extra shank of rivet when put through sheet metal holes should be ______.
1.5x diameter.
Dimensions of rivet head when driven:
1.5x wide.
.5x tall.
Two types of aircraft structures:
Stressed skin.
Truss type.
Three categories of stressed skin aircraft:
Monocoque.
Semi-monocoque.
Reinforced shell structure.
Purpose of formers:
Vertical pieces that form the shape of the structure.
Purpose of longeron:
Provide longitudinal support of an aircraft structure.
Purpose of a bulkhead:
Separate the major compartments of an aircraft structure.
Name the structural components of a wing and their purposes.
Spar- the load bearing member in leading and trailing edge.
Ribs- join the spars and form the wing curvature.
Stringers- connect the ribs.
Define tension.
The pulling apart of a component.
Define compression.
The pushing force on a part from both sides.
Define torsion.
A combination of compression and tension forces on a component.
Purpose of cladding:
To protect the metal from air and water - preventing corrosion.
Purpose of alodining:
Chemically creates an oxide film.
Purpose of priming a part:
Bonds paint to alodined material.
Tools needed to rivet:
Bucking bar.
Rivet gun.
Correct sets for the rivet being used.
E =
Raised circle.
Zinc.
7050 T73.
