Ground Operation and Servicing Flashcards
What is the procedure for extinguishing an induction system fire that occurs during starting of a reciprocating aircraft engine?
A fireguard that is familiar with the aircraft’s induction system should be standing by with a CO2 fire extinguisher during the engine start. If an engine fire develops, continue cranking to start the engine and blowout the fire. If the engine does not start and the fire continues to burn; discontinue starting. The fireguard should extinguish the fire using available equipment.
What is the purpose of pulling a propeller through by hand for two or three revolutions prior to starting some reciprocating engines?
The purpose is to detect a hydraulic lock if one is present. Any liquid present in the cylinder will be indicated by an abnormal effort required to rotate the propeller, or by the propeller stopping abruptly during rotation.
What damage is most likely to occur if force is exerted on the crankshaft when there is a liquid lock?
The force can bend or break a connecting rod.
What information must be located on or near fuel filler openings? Oil filler openings?
For normal category aircraft, the word “fuel” and the minimum fuel grade or designation for the engine. For transport category aircraft, the same information listed for normal category. Oil filler openings require the word “oil” to be marked at or near the filler cover.
Describe the system used to designate performance rating of aviation gasoline.
For fuels below grade 10O, octane numbers are used, such as 91/96. The fuel is compared with mixtures of iso-octane and normal heptane. Thus, grade 91 fuel has the same knock characteristics as a blend of 91 percent octane and 9 percent heptane. When two numbers are used, the first number is the lean mixture performance rating, while the second number is the rich mixture performance rating.
For fuels above grade 100, the numbers represent the performance rating of the fuel compared to 100 percent iso-octane. That Is, its knock-free power available as compared with that available with pure isooctane. The first number is the lean mixture performance rating. The second number is the rich mixture performance rating.
What would be the result of operating an aircraft reciprocating engine using a lower grade of gasoline than that specified for the engine?
There would be a loss of engine power, efficiency, and possible detonation.
Why should an aviation mechanic know the meaning of the standard light signals which are used by control tower operators?
If radio communication is not possible, the light signals may be used for taxi control when an aircraft must be taxied to another part of the airport.
Which publication lists the standard FAA hand signals a taxi signalman should use?
The FAA Airman’s Information Manual (AIM).
What will be the result of mixing aviation gasoline with jet fuel in a turbine engine?
When aviation gasoline is mixed with jet fuel, the tetraethyl lead in the gasoline will form deposits on the turbine blades and vanes. Continued use of mixed fuels may cause a loss in engine efficiency. However, there will be no detrimental effect on the engine if such usage is on a limited basis.
What may result if gasoline that is contaminated with jet fuel is used in a reciprocating engine?
Gasoline which is contaminated with jet fuel is unsafe for use in a reciprocating engine and can result in complete engine failure.
When towing an aircraft with a tow tractor, what brakes should be used to stop the aircraft?
The tow tractor brakes and the aircraft brakes should both be used. Use of the brakes should be coordinated by the man in the cockpit.
What methods should be used to aid reciprocating engine starts in cold weather?
Use of pre-heat and oil dilution as needed; and proper mixture and priming procedures recommended by the aircraft manufacturer for the engine! carburetor combination.
What are the physical and safety requirements for starting and running a powerplant?
Use proper starting checklist; position aircraft into the wind; check prop blast area; secure external power cart; and use a fireguard.
What are the starting safety procedures when hand propping a small engine?
Fuel on, switch off, throttle closed, and brakes on. Contact is called and the switch is placed “ON.” Be sure the ground is firm and do not lean into propeller arc.
What type of knots should be used when using rope to secure light aircraft?
Antislip knots such as the bowline.
