3272-11 system (1.7)

A turbo fan CAU used for air cycle cooling will. not affect the charge air pressure. decrease pressure and temperature of the charge air. increase the pressure but decrease the temperature.

A cabin humidifier is operated. on the ground. at high altitudes. at low altitudes.

International markings for air conditioning pipelines are. triangles. rectangles. dots.

When the refrigerant dissipates heat in a vapour cycle system. the vapour converts to a liquid. the liquid sublimates. the liquid converts to a vapour.

The effective temperature of a cabin is given by. temperature, humidity, thermal inertia and heat load. temperature only. temperature and humidity.

The heat exchanger in a turbo-fan system is cooled by. air bled from the main cabin supply duct. ambient ram air. engine bleed air or blower air.

Subsequent to passing through the primary heat exchanger, the supply air in a turbo-fan cold air system flows to the. inter cooler or secondary heat exchanger. fan. turbine.

In the case of a vapour cycle cooling, system heat is removed from the charge air by. reducing the pressure of a vapour. changing a liquid into a vapour. changing a vapour into a liquid.

An aircraft cabin is air conditioned and pressurized in order to. ensure that the pressure within the fuselage is always less than the ambient pressure, thus increasing the fatigue life of the fuselage. ensure that the air density within the cabin is maintained at a lower figure than outside the cabin in order to prevent moisture precipitation during rapid decompression. maintain human efficiency and comfort during flights at high altitudes.

The rate of flow of air from the punkha louvers should not be less than. 300 ft/min. 200 ft/min. 25 ft/min.

The purpose of the differential capsule in a pressure controller is to control. the rate of pressurisation. cabin differential pressure. cabin air flow.

The basic system of cabin pressurisation is to arrange a constant. outlet and vary the inlet.. inlet and vary the outlet. inlet and outlet.

The signal line between the controller and discharge valve is leaking. This will cause. it will not effect on cabin pressure. the cabin pressure to decrease. the cabin pressure to increase.

As an aircraft descends from cruising altitude (34,000ft), the cabin altitude must. increase. decrease. stay the same.

Cabin pressure is normally controlled by the rate of. air supply. climb or decent. air discharge.

During taxiing, the cabin pressure in a large aircraft is. at atmospheric pressure. below atmospheric pressure. above atmospheric pressure.

The electrical spill-valve operates on signals from. the venturi metering duct. the latching solenoid. the pressure controller.

On the ramp, the pre-cooler obtains its cooling action by. fan inducement. gas expansion. ram air.

Cabin outflow valves provide. outflow of cabin pressure and pressure warning. outflow of cabin pressure and ventilation. cabin positive pressure and negative (suction) pressure.

Pressurisation system operation may be inhibited by. air/ground microswitches. flap microswitches. throttle microswitches.

During a pressurisation check at maximum differential, if the engines are shut-down. cabin ROC indicator gives indication of cabin seal efficiency. aircraft remains pressurised until the dump valve opens. outflow valve opens immediately.

If the pressure controller is set to 0 ft. cabin remains at sea level until maximum differential. cabin will not pressurise. maximum differential is reached immediately after take-off.

Cabin differential pressure is the pressure difference between. the pressure inside the aircraft and the ambient air pressure. 8,000ft and standard barometric pressure. sea level air pressure and indicated dynamic pressure in the cabin.

In the flightdeck of an unpressurised aircraft, there is a gauge that shows. aircraft altitude. cabin differential pressure. cabin pressure altitude.

Prior to conducting a ground pressurisation test, it is necessary to. reset/disable the pressure controller. disconnect the emergency pressure relief valve. set QFE.

When pressurising the aircraft on the ground for test purposes, internal doors, cupboards etc. must be. all open. removed. all closed.

On touch -down of aircraft. the outflow valve will be shut. the cabin pressure will be zero. the outflow valve will be fully open.

Before carrying out a ground pressure check,. set altimeter to QNH. check all pitot and static lines are fitted. turn on all instruments.

A comfortable rate of cabin altitude climb for passengers is. 500 ft. per min. 300 ft. per min. 100 ft. per min.

With a pressurised aircraft at maximum differential pressure and a cabin pressure increase occurs, the differential capsule in the pressure controller will. let pressurisation to be switched off until leaks cause a drop in pressure. have a constant mass flow. let all pressurising air to be spilled overboard.

Pressurisation control ensures that. at operational altitude the cabin altitude is below 10,000 ft. pressurisation does not start before aircraft is above 8,000 ft. the cabin is always maintained at sea level.

Rate of change of cabin pressure is most noticeably shown on a. cabin V.S.I. cabin altimeter. cabin pressure gauge.

The control of ventilating and pressurising air released to atmosphere is achieved by a. pressure controller/dump valve combination. discharge valve/inwards relief valve combination. pressure controller/discharge valve combination.

When an aircraft has reached max. diff. and is at constant level (altitude) the system allows for. constant mass flow. all pressurising air to be spilled overboard. pressurisation to be switched off until leaks cause a drop in pressure.

Cabin altitude in pressurized flight is the. pressure altitude of the cabin as corrected to mean sea level I.S.A. conditions. altitude at which cabin altitude equals outside air pressure. altitude corresponding to cabin pressure irrespective of the altitude for the aircraft.

Cabin differential pressure is the difference between. 8,000 ft and sea level. cabin pressure and ambient pressure. I.S.A. conditions and aircraft altitude.

During normal pressurized climb following take-off. the cabin R.O.C. is more than ambient R.O.C. the cabin R.O.C. is less than ambient R.O.C. the differential pressure is constant.

Cabin rate of climb is shown by. warning lights. a special instrument. a double scale on the aircraft.

Control of rate of change of cabin pressure is. equally important in descent and ascent. most important in descent. most important in ascent.

Cabin pressure is maintained by. controlling the output of the compressor. controlling the supply of air to the cabin. controlling the amount of air discharged from the cabin.

If cabin height is set lower than airfield height when the aircraft is on the ground with squat switches overridden, then the outflow valve will normally. open. remain closed. not operate.

Cabin pressure controller maintains a pre-set cabin altitude by. regulating the position of the outflow valve. regulating the position of the inward relief valve. regulating the mass flow into the cabin.

When the cabin differential pressure has reached the required value and the height is maintained. the pressure system ceases to function until the cabin pressure is reduced. constant mass airflow is permitted through the cabin. all pressurized air is spilled to atmosphere.

The principle of cabin pressurisation is. cabin altitude climbs eventually to that of the aircraft. whilst the aircraft climbs to altitude, the cabin climbs to a lower altitude. cabin altitude will always maintain a constant differential to that of aircraft altitude.

A cabin pressure air leak from the front of the fuselage is. not effective in any way. most desirable because it increases the air-flow. most undesirable because of the drag created.

Which component must be isolated when carrying out a ground cabin pressure test?. Pressure relief valve. Pressure discharge valve. Pressure regulator controller.

Would you operate the flying controls during a cabin pressure ground test?. yes. no. occasionally.

When the aircraft has reached its maximum cabin pressure differential the. discharge valve closes. discharge valve opens. mass flow ceases through the cabin.

If the cabin pressure fails to reach its maximum cabin pressure differential the. discharge valve should be adjusted. outward relief valve is inoperative. pressure controller should be adjusted.

'Pitot' and 'Static' lines during a cabin pressure test should be. cross connected. connected. disconnected,.

Cabin differential is determined only by. the height at which the aircraft is flying. the selected cabin height. the height at which the aircraft is flying and by the selected cabin height.

An aircraft has a maximum differential pressure of 8.5 PSI at cruising altitude. If the ambient pressure is 2.9 PSI, the pressure inside the cabin at cruising altitude would be. 8.5 PSI. 11.4 PSI. 5.6 PSI.

Rate of change of cabin pressure is. selected by the pilot and controlled by the pressure controller. automatic. selected by the pilot and controlled by the spill valve.

During a normal climb from aerodrome level with the pressurization system 'ON'. the pressurization system does not control pressure until 10,000 ft is reached. the cabin differential pressure is maintained constant. the atmospheric pressure decreases more quickly than the cabin pressure.

If cabin pressure is increasing, the cabin rate of change indicator will show. a rate of descent. a rate of climb. zero, provided the rate of change is within the normally accepted limits.

If an altitude of 8000 feet is selected on the cabin pressure controller and provided maximum cabin pressure differential is not exceeded. sea level cabin conditions will be maintained to 8000 feet aircraft altitude. 8000 feet cabin conditions will be maintained at aircraft altitudes above 8000 feet. 8000 feet cabin conditions will be maintained at all aircraft altitudes from sea level.

When air is pressurized, the oxygen content. increases. remains constant. decreases.

The outflow of air from the cabin is regulated by. the outflow valves. the dump control valves. the vent valves.

The cabin differential pressure is. the equivalent height of the aircraft above sea level. the difference between cabin pressure and atmospheric pressure. the actual height of the aircraft above sea level.

The cabin altitude is. the difference between cabin pressure and atmospheric pressure. the equivalent height of the aircraft above sea level. the actual height of the aircraft above sea level.

Ditching control is used for. closing all valves and inlets. rapid aircraft depressurisation. deploying life rafts.

Cabin pressure controller maintains a particular cabin altitude by control of. cabin mass air flow. inward relief valve position. outflow valve position.

A water separator would be installed in a pressurization system to: collect any rain accompanying the ram air. extract surplus water from the charge air. extract water from the cabin air before it is discharged to atmosphere.

The cabin rate of climb is shown. on a specific indicator. as being inside or outside limits by green and red lights, a gauge being used. by a differential scale on the aircraft rate of climb indicator.

When cruising near the operational ceiling, the flight altitude set on the pressurization control panel may be 500 ft. more than the actual flight altitude so as to prevent. pressure controller hunting. safety valve operation. inward relief valve operation.

The pressure controller activates. the spill valve. the blower or compressor. the cabin discharge valve.

If an aircraft is operating at 40,000 ft. the pressurization ensures that. sea level pressure is maintained in the cabin. the cabin pressure is progressively increased until the operational height is reached. the cabin pressure is equivalent to an altitude of less than 10,000 ft.

To avoid discomfort, the rate of change of pressure should be low, particularly. when cabin pressure is decreasing. during descent. during ascent.

A silencer is installed in a pressurization system to reduce. engine noise coming through the ventilators. the noise from the high speed of airflow within the system. the noise from the blowers and/or compressors in the system.

If the pilot selected a cabin height of 8000 ft. whilst taxiing and activated the pressurization system, the cabin pressure would. decrease to a pressure equivalent to about 500 ft. remain at ground level pressure. decrease to a pressure equivalent to 8000 ft.

An inward relief valve is installed in a pressurization system to ensure that the pressure hull of an aircraft is not subjected to: too high an internal pressure. forces which would cause the aircraft to explode. a high negative differential pressure.

Inward vent valves are fitted to. increase ventilation. limit positive differentials. limit negative differentials.

An inward relief valve will operate. after an aircraft has landed, to restore ground level conditions is the cabin. when cabin pressure is lower than ambient pressure. when climbing with pressurization 'OFF'.

Inward vent valves will operate when. depressurising after descent. cabin altitude exceeds aircraft altitude. aircraft altitude exceeds cabin altitude.

A safety valve will normally relieve at. lower differential pressure than the discharge valve. higher differential pressure than the discharge valve. negative differential pressure.

Ditching control is used to. maintain cabin pressure at sea level. close the outflow valves. achieve rapid depressurisation.

On an aircraft employing a heater system on the air conditioning system, after an overheat, how is the heater reset?. After cooling below 300°C it auto resets. On ground only by engineer. After it cools the pilot resets.

A negative differential pressure is prevented by. a blow off valve. an inward relief valve. a spill valve.

Failure of the normal maximum differential pressure control is catered for by. inwards relief valve. cabin safety relief valves. spill valves.

Inwards relief valves usually open at a negative differential pressure not exceeding. 0.16 p.s.i. 1.2 p.s.i. 0.5 p.s.i.

Failure of the normal maximum pressure differential control is allowed for by fitting. inwards relief valves. airport altitude selectors. safety relief valve.

A cabin altitude is protected against reaching an altitude of 13,000 ft. by. altitude sensor. cabin over pressure relief valve. bellows in the outflow valve.

To what position is the inward relief valve spring loaded?. Open. Both position. Closed.

The inward relief valve is usually set to operate at a cabin differential of. -0.5 PSI. +0.5 PSI. +9.25 PSI.

Inward relief valves are interconnected in pressurized aircraft. to achieve maximum pressure differential. to relieve cabin pressure and allow outside pressure to be greater. to allow controlled pressure during descent.

If the cabin altitude increases above the normal maximum. an inward relief valve opens. a warning light comes on in the cockpit. compressor delivery is automatically boosted.

Which of these barometric instruments uses a restrictor to compute its output?. VSI. Machmeter. ASI.

Indicator glasses are 'bloomed' to. reduce reflections. minimise parallex error. render dust unable to settle.

A standby ADI uses. a vertical gyro. a space gyro. an earth gyro.

Slat asymmetry may be monitored by using. position pick-offs. spring actuators. torque sensors.