M11.3 Flashcards
What are most modern aircraft constructed using? 11.3
Most modern aircraft are constructed using a Semi‑monocoque construction.
What is main advantage of semi Monocoque construction
failsafe design
the skin is stressed and supported internally by numerous structural elements, such as bulkheads, frames, longerons, and stringers.
loads are spread through a variety of paths, partial failure without affecting the overall integrity of the aircraft structure.
What is a Pratt truss?
wooden longerons served as the main longitudinal structural members. Wood struts supported and held the longerons apart. Two piano wire stays crossed each bay, or space, between the struts.
This is used manly on oilers aircraft
What is a warren truss?
longerons are solely connected with diagonal members
truss can carry both tension and compression
What is stressed skin fuselage?
all the loads are carried in the exterior skin.
does not require the angular shape needed for a truss, but can be built with a very clean, smooth, and aerodynamically efficient shape.
What is the construction of most pressurised aircraft?
nearly all pressurised aircraft have a Semi-Monocoque construction.
What is done during the manufacture of a pressurised aircraft and were is it applied?
Aircraft fuselage is assembled using a two-part polysulfide sealant
The sealant is applied between skin joints and along seams to provide a leak-free fuselage. It must also be used on skin repairs and patches. Durlac
What is a faying seal?
where two pieces of metal overlap
External parts of aircraft
Applied on joggled joints
A bead of sealant is placed between the two overlapping pieces of metal that are being joined
The excess sealant the is squeezed out when riveting is smoothed to improve aerodynamics.
Provides pressurisedseal
What is a fillet seal?
A fillet seal is used when two pieces of metal are joined together, e.g. a stringer to the skin.
Internal
How do Electrical and Flying Control Cable go through bulk heads?
Need to be sealed
electrical cables are sealed using specially designed rubber or silicon seals or sealant plates
Control cables use fairlead. pressure seals which grip tightly enough to prevent pressure loss but not enough to hinder movement of the cable.
How are wings attached to the fuselage?
Can be attached above or below fuselage.
fuselage can be notched or cut out to accept a centre wing section.
Fittings or lugs are mounted on the frame mate, and on the forward and aft wing spar, for attachment to bolts or other fasteners. Very close tolerances.
Attached to areas to that transfer the loads of on wings to logerons and beams
How is a vertical stabiliser connected to the fuselage?
The vertical fin is typically attached using bolted fittings on a frame member or bulkhead. The attachment fittings on the stabiliser are usually on the front and rear spars.
similar way to the wings
How is a horizontal stabiliser connected to the fuselage?
Some horizontal stabilisers are attached directly to the vertical stabiliser; this means they require no additional attachment points to the fuselage,
Other horizontal stabilisers are attached to the fuselage frames that are strengthened in the attachment areas. Forward and rear spars of the tailplane section usually support the fittings attached to the fuselage frame.
What does the engine nacelle contain?
contains a firewall between the engine, pylon, and wing structure.
Where are the attachment points located and why?
attachment point is the wing spar(s) or a framework attached to the spars. The landing gear must be strong enough to withstand the forces of landing when the aircraft is fully loaded.
What is used to secure seats in aircraft?
passenger and flight crew seats are secured to longitudinal tracks using quick-release fasteners
These tracks might be called L-tracks or I-tracks, depending on the manufacturer,
Where and how are seat tracks installed?
tracks are bolted or riveted to the tops of the floor, with beams running down the length of the passenger cabin compartment and flight deck.
What do seat tracks allow the operator to do?
adjust the pitch, forward or aft, between each row of seats, and to configure the aircraft with more or fewer seat rows.
What, other than seats, can be secured by seat tracks
Seat track fasteners can also be used to install cabin partitions, such as galley installations.
How are seat track fittings made up?
made up of two spaced stud portions, which are attached to the front and rear legs.
The fittings are mounted with a spring-loaded pin
What are the three types of fuel tanks?
Rigid removable
Flexible bladder
Integral
What is the main purpose of the engine nacelle?
To provide aerodynamic smoothness and reduce drag
What are the three types of horizontal stabiliser?
fixed stabiliser, often referred to as a ‘tailplane’, comprises two fixed aerofoils
stabilator, this is a one-piece all-moveable tail that pivots up and down from a central hinge point
variable incidence tailplane, which is simply referred to as the ‘stabiliser’, is also a one-piece all-moveable tail.
How is the vertical and horizontal stab constructed
Leading edge spar
Trailing edge spar
Ribs
