11.3 AEROPLANE STRUCTURES

Question 1

What are the 3 aircraft fuselage constructions?

Answer 1

Truss type (Pratt or Warren)
Monocoque type
Semi-monocoque type

Question 2

Pratt truss ?

Answer 2

→ wooden longerons (main longitudinal structural members)
→ Longerons supported by wooden struts

Question 3

Warren Truss ?

Answer 3

→ Longerons connected with diagonal members
→ carry both tension and compression

Question 4

How is a fuselage pressurised ?

Answer 4

• Air pumped into cabin after take off
• Results in difference outside/inside cabin pressure
• Differential pressure is regulated/maintained throughout flight
• Causes significant stresses leading to metal fatigue
• Semi-Monocoque construction

Question 5

2 sealant application methods on aircraft fuselage ?

Answer 5

• Faying seal (2 metals overlap)
• Fillet seal (corner)

Question 6

Why must electrical and flying control cable must be sealed ?

Answer 6

• prevent excessive pressure leaks as they pass through pressure bulkheads
• rubber, silicon seals or sealant plates

Question 7

Common fuselage on modern day aircraft ?

Answer 7

• Semi-monocoque construction

Question 8

What is a stressed skin fuselage

Answer 8

All loads carried in the exterior skin

Question 9

How are electrical cables and flying control cables sealed to prevent excessive pressure leaks

Answer 9

Special designed rubber or silicon seals used

Question 10

What is the pylons structural purpose

Answer 10

Transfers thrust generated by engines to airframe

Question 11

Passengers and flight crew seats are secured to longitudinal tracks using what type of fasteners

Answer 11

Quick release fasteners

Question 12

What are the seat tracked bolted/riveted to

Answer 12

Floor beam

Question 13

Cargo loading system components include

Answer 13

-transport components
- guidance components
- locking components

Question 14

What type of door is the ‘main entry doors’

Answer 14

Plug type

Question 15

What type of door is a ‘service door’ e.g. potable water system

Answer 15

Non plug type

Question 16

What type of door are cargo doors

Answer 16

Non Plug type

Question 17

Explain plug type door

Answer 17

• Seal itself by utilising differential pressure
• One side has higher pressure so it wedges it in

Question 18

Explain non-plug type door

Answer 18

Open outwards and use locking mechanisms such as latches

Question 19

What are the left doors of the aircraft usually used for

Answer 19

Passenger entry

Question 20

What are the right doors of the aircraft usually used for

Answer 20

Galley servicing

Question 21

If a door is incorrectly latched/open is a warning given to a flight crew

Answer 21

Yes

Question 22

What do the door frame house

Answer 22

Pressure stop fittings

Question 23

What is the function of the pressure stop fittings and how is it achieved

Answer 23

Holds the door closed when cabin is pressurised

By a ‘stop pin’

Question 24

How are door seals held in place

Answer 24

Adhesive compounds, screws

Question 25

> than 45,500 kg/> than 60 passenger seating capacity shall be equipped with what

Answer 25

-compartment door between cabin and flight deck

Question 26

Should the aircraft door be opened if the cabin pressure ‘indicator’ is lit

Answer 26

No, risk of door violently opening and injuring outside personnel

Question 27

What are safety gags used for

Answer 27

Prevent hydraulic actuation of cargo doors

Question 28

What do witness points indicate on cargo door

Answer 28

If latches have been fully engaged

Question 29

What device are doors usually fitted with to ensure they are securely locked for flight

Answer 29

Proximity devices

Question 30

What are doors usually fitted with to ensure they are securely locked for flight

Answer 30

Proximity devices

Question 31

Explain passenger windows

Answer 31

- plug type - made of acrylic plastic - 2 layers of acrylic plastic for failsafe reasons

Question 32

Explain flight deck windows

Answer 32

- usually 6 flight deck windows - constructed from laminations of tempered glass and plastic - electrically heated - silicon seal in between windows and frame to bond

Question 33

What do you inspect for window damage

Answer 33

- Delamination and bubbles - chips, cracking, scratches

Question 34

What does the keel beam support

Answer 34

- wheel well area