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Heating and preparations for the launch of aircraft engines.

Turbojet engines are necessary to heat at temperatures below - 250˚C, for their greasing apply oils with small viscosity of MK - 8 and MK - 8P, besides these engines practically do not have mates, working in sliding.

Most commonly used mobile heaters such as MPM-8K, AP - 5, UPV - 1 and self-propelled UMP – 350 and other are applied for heating engines.

At some airports fixed heating system engines are designed and installed, whereas the heater can be used instead jet engines, spent resource. Coming from the engine gases are used to heat radiators through which the fan is fed fresh air. After heating in the heater, the air enters the system of distribution and goes to the parking lot, where on the sleeves directly to the engine. Such systems are useful to establish at airports that operate predominantly piston technique.

Since the main task is to heat oil to a temperature of 20 ... 40 ° C, hot air or air-gas mixture is fed to such zones of the engine in which the bulk of the oil. On a turboprop engine - front casing, oil tank and oil cooler, for turbojet engine - gearbox drive motor units and starting aggregates. Heating of a turbojet engine can also be made by entering the path of hot air in the engine through the jet nozzle or input devices, while increasing the time of oil heating. To circulate the air through the engine output device plugs should be slightly open.

Preparation of turboprop engine for heating is executed in the next order:

- establish plugs on the exhaust pipes and input devices;

- remove the plugs from inlet ducts, oil cooler and open the leaves of oil cooler;

- wear winter blankets on the nacelle;

- attach to the inlet hatches of the hot air heater hose adapters;

- start heaters, regulate by metering valves the air temperature on the thermometer ÒÖÒ-9 (85…900 Ñ), attaching the hoses to the heaters and conduct heating to the oil temperature at the inlet of the engine not lower than 30˚C (for AN-24). The required time for this depends on outdoor temperature and wind speed and in average it is equal to: at temperature – (20 ... 30 ° C) for at least 1 hour; at temperature - (30 ... 40 ° C) not less than 1.5 hours; at temperature below - 40˚ C at least 2 hours. Time of heating is increased at high wind. To decrease the losses of warm air and to accelerate heating, it is necessary, in these conditions, carefully to cover power plant. At the end of preheating, when the oil temperature becomes close to 30 ° C, by one sleeve through the open leaves during 2 ... 3 minutes should be warmed oil cooler.

 

47. What kind of engine units are heated and under what temperatures of ambient air?

48. When is the launch engine on the ground?

Starting engine on the ground performed:

-before flight on a mission (after boarding and loading aircraft);

-if necessary to check the engine after the removal of any defect in his system;

-in cases provided by the regulations;

-after 72 hours of parking;

-after installation of the engine on the plane in order to de-preservative and validate;



-after replacement of equipment, such as propeller, regulator or command-and-fuel unit, as well as in the cases provided by instruction.

 


Date: 2015-12-17; view: 737


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