- Settore: Aviation
- Number of terms: 16387
- Number of blossaries: 0
- Company Profile:
Aviation Supplies & Academics, Inc. (ASA) develops and markets aviation supplies, software, and books for pilots, flight instructors, flight engineers, airline professionals, air traffic controllers, flight attendants, aviation technicians and enthusiasts. Established in 1947, ASA also provides ...
A type of molecular structure in which the molecules of a material are arranged in a definite pattern throughout the material. This pattern of molecular arrangement is called a crystal lattice.
Industry:Aviation
A type of mount that supports the engine on steel-backed rubber pads. These pads isolate the engine from the airframe and prevent vibrations damaging the structure.
Industry:Aviation
A type of nondestructive inspection in which a piece of material is examined for hidden flaws. Pulses of mechanical vibration at an ultrasonic frequency are passed through the part being tested. This vibration produces an electrical signal which is displayed on the screen of a cathode-ray oscilloscope.
The display produced by the vibrations passing through the material being tested is compared with the display produced by a vibration of the same frequency passing through a similar material known to have no faults. Any difference in the displays is an indication of an internal fault.
Industry:Aviation
A type of nondestructive inspection using X-rays and gamma rays to determine the condition of an aircraft structure at locations which could not otherwise be inspected without disassembly. Radiographic energy is passed through the structure and it exposes a photographic film or excites a fluorescent screen. Faults show up because their density is different from that of sound material.
Industry:Aviation
A type of nondirectional radio antenna used with an automatic direction finder. The sense antenna picks up signals with equal strength from all directions. An ADF system uses two antennas — a loop antenna and a sense antenna. The loop antenna is highly directional; the strength of the signal it picks up changes with the direction between the antenna and the station. But the signal strength is the same if the station is in front of the antenna or behind it.
The signals picked up by both the loop antenna and the sense antenna are fed into the same equipment, and as the two signals mix, they form a pattern that allows the ADF system to measure the exact direction between the loop antenna and the station being received. Using the sense antenna eliminates the problem of 180° ambiguity. It allows the system to distinguish whether the station is in front of the antenna or behind it.
Industry:Aviation
A type of nozzle used to fuel aircraft with a pressure, or single-point, fueling system. The nozzle is connected to the fueling receptacle in the aircraft, and the handles are turned a portion of a turn to lock it in place.
Industry:Aviation
A type of nut with a built-in locking device that makes the nut tightly grip the threads of the bolt. This locking device may be a fiber collar, with a hole slightly smaller than the major diameter of the bolt threads, or it may be a portion of the threads in the nut that is slightly out of phase with its main threads.
A self-locking nut must be turned onto a bolt with a wrench and grip the bolt threads tightly enough that vibration will not cause it to loosen or back off.
Industry:Aviation
A type of ohmmeter used for measuring very low values of resistance. Voltage across the meter is adjusted until the meter pointer deflects full scale. Then, the unknown resistor is connected in parallel (in shunt) with the meter. The resistance of the unknown resistor is indicated by the decrease in the current flowing through the meter.
Industry:Aviation
A type of oil pressure relief valve used in some of the larger aircraft engines.
When the oil is cold, two springs hold the pressure relief valve on its seat. But when the oil warms up, a thermostatic valve directs oil against a piston in the relief valve. This oil disables one spring and allows the oil pressure to be controlled by only one spring.
The initial high oil pressure forces the thick, cold oil through the engine and assures that all the bearings are lubricated when the oil is cold.
Industry:Aviation
A type of one-way valve that uses a swinging gate, or flapper, to control the flow of fluid. Gate-type check valves are used in multiengine aircraft vacuum systems to isolate one of the pumps if it should fail.
Industry:Aviation
