Airframe General

Question 1

an aircraft typically consists of what?

Answer 1

fuselage, wings or mainplane and tail section comprised of a fin and tail plane

Question 2

what are the primary flight controls?

Answer 2

aileron, rudder and elevator

Question 3

what are the secondary flight controls?

Answer 3

flaps

Question 4

what are the three fuselage types?

Answer 4

truss, monocoque, semi-monocoque

Question 5

what is the construction of a truss fuselage? (3)

Answer 5

a truss type structure (that has internal framework that carries most of the stress)

Question 6

what is the construction of a monocoque fuselage?

Answer 6

• skin carries all structural stresses

- formers maintain fuselage shape

Question 7

what is the most prevalent form of fuselage construction?

Answer 7

combination of truss and monocoque, semi-monocoque

Question 8

what is the construction of a semi-monocoque fuselage?

Answer 8

a light metal framework normally covered by an aluminium alloy skin.

Question 9

what is a bulkhead?

Answer 9

A bulkhead is the material partition such as a wall, curtain or screen that divides an aeroplane into various classes or sections

Question 10

what is a longeron?

Answer 10

spar-like structures that run lengthwise of the aeroplane’s fuselage or spanwise of a wing.

Question 11

what is a stringer?

Answer 11

strip of wood or metal to which the skin of an aircraft is fastened.

Question 12

the design of a semi-monocoque fuselage allows for what?

Answer 12

• makes it so that the skin bears most of the load like monocoque fuselages but since the internal framing is sharing the load the skin can be thinner.

Question 13

wing designs fall into what 3 categories?

Answer 13

multiplane, braced monoplane, unbraced monoplane,

Question 14

the design of the unbraced monoplane is what?

Answer 14

the wing is attached to the fuselage at the root only so the thickness becomes vital to building insufficient structural strength to support the loads of the flight without wing twisting and bending

Question 15

what is a spar?

Answer 15

The spar is often the main structural member of the wing, running spanwise at right angles to the fuselage

Question 16

what is ribs?

Answer 16

provide shape of wing and transfer some load from skin.

Question 17

what is a former?

Answer 17

a former is a structural member of an aircraft fuselage

Question 18

what is skin?

Answer 18

the outer surface which covers much of its wings and fuselage `made of aluminium alloy, stressed skin design. allows for wing skin to absorb some of the forces applied to the wing and prevent bending and twisting.

Question 19

what are stringers?

Answer 19

long thin extensions affixed to the inside of the skin to increase its stiffness without the weight gain from making the skin thicker.

Question 20

what is empennage

Answer 20

the entire tail section of the aircraft, including both the horizontal and vertical stabilizers, the rudder and the elevator.

Question 21

what are the loads experienced on take-offs and landings?

Answer 21

gust loads - caused due to a sudden change in velocity of the air
manoeuvring loads - these are the g forces an aircraft can experience
control surface loads - caused when the control surfaces are deflected in order to manoeuvre the aircraft
pressurisation loads - due to the expansion and contraction of the cabin with altitude.

Question 22

what is wing loading?

Answer 22

wings are subject to loading during flight. moved by turbulence, they want to bend upwards due to the lift they create and are forced downwards due to weight.

Question 23

what does wing loading do?

Answer 23

can cause compression and tension of the structure leading to stress cracks, weakening the structure over time.

Question 24

what are the characteristics of an aluminium airframe? (4)

Answer 24

• provide a large proportion of the structural strength of the aircraft.
• looked after and report any damage to engineer
• designed in a way that any overstressing will result in a gradual failure not sudden.
• flexible and can withstand tension but susceptible to buckling under compression and fatigue,

Question 25

what are the pre-flight checks of aluminium airframes?

Answer 25

• look for any cracks or ripples in the skin
• loose or missing rivets
• anything out of the ordinary that would indicate overstressed airframes.

Question 26

what are the characteristics of composite airframes? (3)

Answer 26

• lighter than aluminium, and less prone to fatigue and corrosion
• most common failure is delamination ( separation of the excessive plies through the failure of the bonding matrix)
• damage is also caused by impact with other objects and notes that light impact damage doesn’t impact composite airframe as much.

Question 27

what are the pre-flight checks of composite airframes?

Answer 27

look out for any dull or whitish areas compared to nearby areas, or cracking on the surface for signs of delamination. also look out for areas where fibre are exposed or sticking out.

Question 28

what are the characteristics of fabric airframes? (3)

Answer 28

• covered in fabric
• must be kept in good condition
• too much sun explore, solvents and dirt can weaken fabric.

Question 29

what are the pre-flight checks of a fabric airframe?

Answer 29

look at seams surface tape and any chords that can be seen, keep fabric clean and remove dirt immediately.

Question 30

how is an aircraft picketed?

Answer 30

face into wind, park brake on, tie-down the wings, chock the wheels, tie the tail and fit any covers that you might have to protect it.

leave some slack so that no unnecessary stress is placed on the airframe.

Question 31

what is the best type of tie-down rope?

Answer 31

nylon rope is best and better than manila.