It's counted in flying hours and flight cycles. The primary concern is flight cycles.
A flight cycle is a take-off and landing. Airlines keep track of the Flight Time (hours) and Flight Cycles on the airframe and the same for the engines. Flight Cycles are primarily important for tracking aircraft metal fatigue and the time on the Landing Gear. The parts on the gear have a Safe Life Limit calculated by the manufacturer based upon fatigue tests and stress analysis. This limit represents the amount of cycles it can be flown before it will begin to develop fatigue cracks. Once the landing gear part reaches that cycle limit, it has to be removed and scrapped. The manufacturer analyzes the gear using various loads such as landing loads, taxiing loads, braking loads, turning loads and calculates a fatigue life for the part. They usually then divide this calculated fatigue life by 4 and this becomes the Safe Life Limit. Dividing by 4 is a safety factor to allow for variations of manufacture and environmental unknowns and statistical scatter in their data. The Airframe is also tested in a fatigue test for 2 or 3 times the time it will be in service. Many airframes have a 90,000 flight cycle limit. Some more. Helicopters will be less. This airframe life limit takes into account air pressure on the fuselage as it cycles from ground to high altitude. Also, a short test flight is counted as 1 flight cycle.
As an example of the difference between hours and cycles, the Aloha Airlines Boeing 737 that lost part of its fuselage had only a little over 35,000 hours on the airframe, but the aircraft had almost 90,000 cycles on it.
It is a manual of the details of structure for a particular aircraft.
It is a manual of the details of structure for a particular aircraft.
structure, ultimately all types of load go to structure like lift load, cabin pressurization load, aircraft maneuvering load etc.
IIt is actually a set of manuals detailing every part of the structure of the aircraft.
Aircraft End-of-Life Solutions was created in 2006.
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Sorry, I want to know the difference between Primary, Secondary and Tertiary structure of aircraft
An aircraft bunker is an hardened structure that is designed specifically to protect aircraft. An extreme example is Zeljava Air Base, in the former Yugoslavia, which has underground aircraft storage areas and an overground runway.
A hangar is a large structure, similar to a garage, in which aircraft are kept.
Answer Yes. If you refer to Janes All the World's Aircraft or other reference and it lists the total aircraft in a countries military, the number would include all branches of service. Is that your Question?
rivets are used in aircraft structure primarily to take shear loads and gives initial stiffness
Basically an aircraft fuselage structure that relies heavily on the strenght of its external skin to support the imposed stress on the aircraft. Monocoque structures have almost no internal frame work. Formers and bulkheads can be used but a true monocoque structure only uses the skin.