11.3 Fuselage Construction And Sealing Flashcards
What are the three aircraft fuselage construction?
Truss type (Pratt or Warren), Monocoque type, Semi-monocoque type
What is a truss?
A form of construction in which several members are joined to form a rigid structure
When was Pratt truss used?
Early aircraft with wooden longerons as the main longitudinal structural members
In warren truss construction, how are the longerons connected?
They are connected with diagonal members
What are the similarities between Pratt and warren type?
Both have longerons, both have horizontal and vertical strut members
What are the differences between the Pratt type and warren type?
Pratt types diagonal stays are cable so they only take tensile loads, warren types diagonal stays are solid metal
What loads do truss take
Tensions and compression
What is stressed skin fuselage?
When loads are are carried in the exterior skin of a fuselage
How and why is an aircraft pressurised
Air is pumped into the cabin after take off and a difference in pressure between the inside and outside the cabin. This is regulated and maintained to ensure passengers have enough oxygen to breathe and move around the cabin without breathing apparatus
What can lead to metal fatigue on the aircraft cabin ?
The difference in air pressure inside and outside the cabin, and the cycling from pressurised to the unpressurised fuselage can lead to metal fatigue
What happens when an aircraft fuselage is pressurised and what is done to solve this?
Causes significant stresses on the structures which causes fatigue over cycles. To address this problem, semi monocoque fuselages were developed to take other stresses off of the fuselage
What are attached to the fuselage?
Wings, stabilisers, engine pylons and landing gears
What are pressurised joints used for?
Creating pressurised joints to make a “wet area” safe or for leak free joints
In the area of component attachment, why must the structure be reinforced?
To ensure all loads are transmitted from these attached assemblies to the fuselage
What are typical seals?
Faying seals, fillet seals
