2. Introduction
Forms main body of aircraft to which wings, tail plane,
engines and gears are attached
In modern aircraft forms a tube structure housing
flight deck, pax cabin, hold and equipment
Also acts as a pressure hull in pressurized aircraft
4. Types
Frame structure:
A box frame made up of a series of vertical, horizontal,
diagonal and longitudinal tubular steel pipes
Design produces a square profiled fuselage
Used in old aircraft and light modern aircraft
Frame takes up all the loads
5. Types
Heavier if shape
altered
Covered with
fabric, fiberglass,
aluminum,
Kevlar e.t.c.
7. Types
Monocoque structure:
Skin takes up all flight and ground loads and shape
gives structure its rigidity
Any damage to skin directs effects its load carrying
capacity
Complications in designing doors windows and
hatches
9. Types
Semi-Monocoque structure:
Loads shared by skin,
frames, stringers and
formers
Tolerant to damage
Good strength to
weight ratio
More redundancy then
monocoque construction
10. Types
Reinforces shell structure:
Best redundancy in shell structure
Reinforced windows, doors and hatch attachment
points
Longerons added for further load distribution, prevent
crack propagation
16. Pressure bulkheads
Pressure cabin terminates at the front and rear
bulkheads
Usually dome shaped for better pressure distribution
In some designs floor part of pressure hull, un-
pressurised hold in this case
18. Cabin floors
In modern designs are not used as bulkheads
Series of panels attached to supporting beams of
aircraft
Honeycomb panels
used for best
weight to strength
ratio
19. Blow out bungs
Plastic blowout bungs to equalize pressure in case of
decompression
20. Windows
Flight deck:
Heated for de-icing
JAR approved for bird strikes
Laminated like car windscreens
Stepped nose profile used in most subsonic airliners
Helps in:
Aerodynamic profiling
21. Windows (flight deck)
Better ground and forward visibility
Reduction in size of screen windows
Sheds water better
Reduces impact force
Reduces pressure loads
25. Windows
Passenger cabin windows:
Form a part of pressure shell of fuselage
Reinforced surrounding structure
Windows fitted from inside and larger then apertures
Two panes with air filled gap in between them
27. Doors
Commonly plug type doors used in commercial
aircraft
Closed from inside with locking pins engaging into
door frame
Open by pulling back on inside and turning/sliding
sideways
29. Doors
Some requirements are:
Must not be located near propellers
Must be able to open with people surrounding it
In emergency, external handle must be able to unlock
door
Must open from both sides, handles to be flushed to
skin
30. Doors
Must be a visual indication of doors being secured and
locked, both externally and internally. E.g. flushing
handle on outside, warning light on the crew warning
panel
Must not jam in emergencies
Must b a means of safe-guarding against inadvertent
operation in flight
35. Fuselage shapes
Fuselages became more
cylindrical to carry more
payloads
Engines had to be added
which added weight
penalties
Large piston engines
give diminishing returns
36. Fuselage shapes
Jet engine:
With its advent fuselage became cylindrical with rounded
nose and a tapered tail
Advantages:
Easy manufacturing
Lower operating costs
37. Fuselage shapes
Better power to weight ratio
Greater cargo and passenger capacity
Easier loading and unloading of aircraft
44. Fuselage mounted engines
Jet engines can also be mounted in fuselage, usually
reserved for combat aircraft
45. Fuselage mounted engines
For twin engine aircraft, engines can also be mounted
to sides of fuselage
Mounted on stub wings
Reduces drag and cabin noise as compared to wing
mounted aircraft
But early onset of stall