11.2 B Airframe Structures

Question 1

Define longeron

Answer 1

Main longitudinal member of fuselage or nacelle

Question 2

What’s the name given for a member that takes a tensile load?

Answer 2

Tie road
(Tension rod)

Question 3

What load does a strut take?

Answer 3

Compression load

Question 4

In a semi-monocoque stressed skin, what are the loads shared between?

Answer 4

Skin and framework

Question 5

What is the purpose of the aircraft frame?

Answer 5

Gives cross- sectional shape, often circular

Question 6

Maintains the contour of the covering, can be a stress bearing component, what is it?

Answer 6

Rib

Question 7

Describe a spar

Answer 7

The main spa wise member of an aerofoil

Question 8

What member assist sheet material in carrying loads along their length?

Answer 8

Stringer

Question 9

What is a bulkhead?

Answer 9

A partition within the structure

Question 10

What is a pressure bulkhead?

Answer 10

Forms the boundary of a pressurised structure

Question 11

How do you know where certain components like frames and ribs are positioned?

Answer 11

Station numbers

Question 12

Explain safe life

Answer 12

The period in which a component is extremely unlikely to fail

Question 13

What is the purpose of using a crack stopper?

Answer 13

Placed at right angles to the crack, which reduces the rate of further cracking

Question 14

What is the difference between aerodynamic and static loading?

Answer 14

Aerodynamic = when in flight
Static = when stationary

Question 15

What are the two types of fuselage construction?

Answer 15

. Monocoque
. Truss

Question 16

How does the truss type work?

Answer 16

Made of members like beams, struts etc then covered in fabric

Question 17

What are the two sections of a monocoque classification?

Answer 17

. True monocoque
. Semi - monocoque

Question 18

What are the main memebersin a true monocoque construction?

Answer 18

. Formers, frame, bulkheads and skin

Question 19

What takes the primary stress in a true monocoque construction?

Answer 19

Skin

Question 20

How is a semi- monocoque differ from a true- monocoque construction?

Answer 20

The skin is reinforced by longitudinal members, therefore both take the loads

Question 21

What is the main advantage of a semi- monocoque structure?

Answer 21

Can withstand considerable damage and still be strong

Question 22

What construction are floor boards?

Answer 22

Honeycomb composite construction

Question 23

Floorboards have a foam tape on the underside where they contacts structure, what about in wet areas?

Answer 23

The edges are sealed up

Question 24

How are the two wings attached to each others?

Answer 24

By the wing box

Question 25

What is the wing box designed to do?

Answer 25

Provides support and rigidity to the wings

Question 26

How is the horizontal stabiliser attached to the fuselage

Answer 26

Box section

Question 27

How is the vertical stabiliser attached to the rear stabiliser?

Answer 27

By large machined fittings

Question 28

The engine pylon is made of a frame and skin but how is it formed to make nacelle and strut?

Answer 28

Riveted and bonded together

Question 29

What is the purpose of nacelles?

Answer 29

They are streamlined enclosures used to house engine and it’s components

Question 30

Due to weight what is the preferred rivet type to join metal parts together?

Answer 30

Solid shank rivets

Question 31

When would you use a blind rivet?

Answer 31

When access to joint is only available from one side

Question 32

What marking do close tolerance bolt have on its head?

Answer 32

A raised or recessed triangle

Question 33

What would you do if a bolt had no head markings?

Answer 33

Do NOT Use as probably a commercial grade bolt

Question 34

What is the most effective assembly method?

Answer 34

Adhesive bonding (Foam cores can also be used)

Question 35

What are the three types of surface protection?

Answer 35

1. Pretreatment 2. Paint coatings 3. Special coating

Question 36

What 2 sections can paint coatings be subdivided into?

Answer 36

1. Primers 2. Top coat

Question 37

For special coatings what is type 1 and type 2?

Answer 37

Type 1- water repellent (silicone free) Type 2- heavy duty corrosion preventative

Question 38

What are the two conditions for water used to clean an aircraft?

Answer 38

. Water between 7 and 8 PH . Chloride level less than 100ppm

Question 39

For an aircraft symmetry check what equipment would you use for small aircraft vs large aircraft?

Answer 39

Small aircraft = steel tale Large aircraft = check the floor