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How is the flame stabilised in the reheat system of a gas turbine engine?. By creating a greater potential between inlet & jet pipe temperatures. By ensuring that the gas velocity is greater than the flame velocity. By ensuring that the flame velocity is greater than the gas velocity.

During operation of the engine equipped with water injection system, the metering of the coolant to the system is. selected by the pilot. due to atmospheric pressure. due to altitude change.

Water methanol injection is used. at high altitude take off conditions only. at a combination of higher than normal air temperatures and high altitude take off conditions. at higher than normal ambient air temperatures only.

A free turbine is usually found on a. turbo-jet. turbo-fan. turbo prop.

A free turbine is. not directly connected to the power output shaft. connected directly to the propeller and compressor. connected directly to the power output shaft.

The fuel flow in a turboprop engine within the constant speed range is controlled. automatically. manually. No Control.

Torque measurement is taken from the. reduction gearbox. prop shaft. free turbine shaft.

Electrical propeller de-icing pads are. at the root. at the tip. on the trailing edge.

Fuel trimming on a turboprop engine is. pilot controlled. governor controlled. automatic.

What controls the fuel trimmer on a turboprop engine?. The blade angle. Propeller Control Unit. Engine Speed Governor.

What is the purpose of the reduction gear on a propeller driven engine?. To maintain a constant propeller blade speed. To enable torque measurement. To prevent the propeller tips reaching the speed of sound.

If an E.P.R gauge is installed on turbofans as a measure of power output, what is used on a turboprop?. gauge. Torque-meter. Thermocouples.

What type of reduction gear is used on most turboprop modern engines?. Helical cut parallel spur gears. Epicyclic reduction gear. Straight cut parallel spur gears.

A turbo-shaft engine has. a mechanical connection between compressor and turbine. a power shaft which is not connected to the compressor. none of the above.

On a twin spool turbo-shaft engine, the free turbine is connected to the. output gearbox. H.P. gearbox. L.P. gearbox.

In the majority of helicopters, the thrust generated by the gas generator is absorbed by the. L.P turbine. Free power turbine. H.P turbine.

An A.P.U has. automatically controlled thrust and is self contained. variable speed and is self contained. constant speed and is self contained.

An A.P.U shut down is initiated by. high oil pressure, fire warning, hot oil temperature. low oil pressure, fire warning, hot oil temperature. low oil pressure, fire warning.

An A.P.U start cycle is completed at. 75% RPM. 95% RPM. 100% RPM.

An A.P.U power lever is located. behind the throttles. at the Flight Engineer Station. An A.P.U is fully automatic and does not require a power lever.

An A.P.U consists of. a power compressor and load compressor. a power compressor and directly connected turbine. a load compressor and free turbine.

When necessary, A.P.U engine cooling before shutdown may be accomplished by. closing the bleed air valve. opening the bleed air valve. unloading the generator(s).

Fuel scheduling during A.P.U start and under varying pneumatic bleed and electrical loads is maintained. automatically by FADEC. manually through power control lever position. automatically by the A.P.U fuel control system.

An A.P.U is usually rotated during start by. a pneumatic starter. a turbine impingement system. an electric starter.

Usually, most of the load placed on an A.P.U occurs when. the bleed air valve is opened. an electrical load is placed on the generator(s). the bleed air valve is closed.

The function of an A.P.U air inlet plenum is to. stabilize the pressure of the air before it enters the compressor. increase the velocity of the air before entering the compressor. decrease the pressure of the air before entering the compressor. .

In a large commercial passenger transport aircraft the A.P.U supplies. pneumatics and electrics. electrics. pneumatics.

When in operation, the speed of an A.P.U. remains at or near rated speed regardless of the load condition. remains at idle and automatically accelerates to rated speed when placed under load. is controlled by a cockpit power lever.

Generally, when maximum A.P.U shaft output power is being used in conjunction with pneumatic power. electrical loading will be automatically modulated to maintain a safe E.G.T. temperature limits and loads must be carefully monitored by the operator to maintain a safe E.G.T. pneumatic loading will be automatically modulated to maintain a safe E.G.T.

An A.P.U is. a self contained constant speed gas turbine engine. a reserved engine in case of a main engine failure. a self contained variable speed gas turbine engine.

When the A.P.U is running and pneumatics are on. bleed valve is closed, surge valve is open. bleed valve is open, surge valve is closed. bleed valve is open, surge valve is modulating.

When is the A.P.U at its greatest load?. With generator loads on line. With bleeds closed. With bleeds open and with generator loads on line.

Auxiliary power units provide. hydraulic and electrical power. pneumatic and electrical power. hydraulic and pneumatic power.

When starting an A.P.U what would the normal duty cycle be on a modern aircraft?. 6 attempted starts per half hour with 5 minutes between attempts. 3 attempted starts per hour with 5 minutes between each attempt. 6 attempted starts per hour with 5 minutes between attempts.

From where does the A.P.U receive a fire signal?. It has its own system. It is dependent on the airframe system. It is dependent on the engine fire system.

What are the two most important signals when monitoring an A.P.U?. E.G.T and RPM. Oil Pressure and Inlet Pressure. E.G.T and Oil Pressure.

One of the accessories driven from the A.P.U gearbox in a centrifugal switch, the purpose of which is to. arm the governed speed indication circuits and max. RPM governor. cancel the ignition circuits and arm the overspeed protection circuits. control starting and automatic extinguishing circuits.

What initiates A.P.U shutdown?. Fire detection, low oil pressure, high oil temperature. Overspeed, fire detection, low oil quantity. Low oil pressure, high oil temperature.

Pipes, electrical cables and associated components of a fire-detection system should be. fire resistant. fire proof. fire retardant.

Acoustic linings made from composite materials are used in what section of the engine?. Not used to suppress noise. Hot section & Cold Section. Cold section only.

Vibration mounts are used for. stopping vibrations entering the engines. preventing engine vibration loads being transmitted to the airframe structure. damping out vibration stresses on engine when being transported on an engine stand.

An aircraft has a heavy landing and on inspection of the engine mounting bolts the bolts torque loading has reduced, you should. An aircraft has a heavy landing and on inspection of the engine mounting bolts the bolts torque loading has reduced, you should. remove bolt and carry out inspection as the bolt may have increased in length due to heavy landing. re-torque bolt up to correct torque value.

Forward engine mounts take which loads?. Thrust, vertical and shear loads. Centrifugal, thrust and axial. Thrust, vertical and impact.

Forward engine mounts take which form?. Castings. Forgings. Fabricated sheet steel.

Pipes around engines are. aluminium. mild seamless steel. stainless steel.

Fibrous metallic lining for noise suppression is used. for lobe type noise suppressors. in cold area. in hot area.

Noise lining in the fan area is made from. layers of bonded resin. porous type Honeycomb and backing sheet. felt with aluminium sheet.

A powerplant consists of. a basic engine plus E.C.U. a basic engine plus thrust reverser, exhaust system and gear box with accessories. the complete engine as it would be found on aircraft including all connections, controls, cowlings, intake etc.

Acoustic blankets are installed to. reduce noise levels. increase thermal efficiency. aid the streamlining of the engine.

When checking the effect of inertia on the engine after heavy landing you would first check the. thrust line. compressor shaft for distortion. module alignment.

Following the reports of a heavy landing you would. carry out a complete visual examination of the power plant. examine the engine mountings and borescope the nozzle guide vanes and turbine. examine the engine mountings and fuse pins.

The purpose of spring back and cushion on an engine power lever is. used when friction builds up in a system. used to prevent the controls hitting the fuel control stops. used when full travel is used but slight movement is still required on the fuel control unit.

What are sometimes installed in an engine mounting system to tune out the worst engine vibrations?. Spring cushioned mounting pads. Vibration absorbers of calibrated weight. Rubber encased wire-mesh vibration isolators.

Where are the lifting points on a high bypass turbine engine?. On the fan and compressor casing. On the fan, turbine and compressor casing. On the fan and turbine casing.

Rubber anti-vibration pads are fitted to engine. components to prevent fatigue. cradles to prevent damage during transportation. pylons to prevent vibration through the airframe.

Engine thrust is transmitted through mountings that. are designed to transmit eng thrust equally through front and rear supports. are designed to prevent the thrust line of the engine varying. allow for radial and axial expansion.

If you reduced the length of bellcrank (2) what would happen to the input to the C.U?. remain the same. reduce. increase.

A fire wire is installed. to withstand inertia, vibration, etc, encountered during normal operation. vertically. horizontally.

Resistive and capacitive type firewires are tested with. megger/voltmeter. megger/ohmmeter. multimeter.

Fire wire clips have rubber in them to. stop heat transfer to the element. insulate the fire wire electrically. support the wire.

Fire extinguishers work by. combining with remaining oxygen to get rid of it. creating more oxygen. reducing oxygen.

Fire detection systems which are routed through another zone. must be protected by the use of heat sinks. must be protected from heat sources in the zone. are not allowed.

The test switch of a continuous loop detector gives a. continuity check. insulation check. bonding check.

What are the types of continuous fire detection system?. Capacitance. Capacitance and resistance. Inductance and capacitance.