PRESSURISATION - Dgca question bank for pilots

Results

#1. Why are some aircraft pressurisation systems to referred to as bootstrap systems?

Because they are air cycle machines.

Because they are vapour cycle machines.

They are activated by pull cords.

They employ refrigerants.

#2. The ditching control valve?

Opens the outflow and inward relief valves.

Closes the outflow valves.

Closes the mass flow controller.

Opens the outflow valves.

#3. The heat exchanger in a bootstrap system?

Cools both the bled air and the compressor outlet air.

heat the incoming air.

Cools the incoming air.

Extracts heat from the exhaust air before it is discharged overboard.

#4. An air cycle machine?

Uses a turbine to reduce air temperature.

Uses freon to reduce air temperature.

Uses freon to increase air temperature.

Uses a compressor to reduce air temperature.

#5. Cabin air pressure?

Is controlled only when maximum pressure differential is reached.

Can no longer be controlled when maximum pressure differential is reached.

Can be controlled either manually or automatically.

Can only be controlled manually.

#6. A pressure cabin is one in which?

Cabin pressure is maintain at sea level pressure.

Pressurisation occurs above 8000 ft only.

A constant differential pressure is maintained at all altitudes.

Cabin pressure is always greater than ambient.

#7. In straight and level cruise flight?

The inward relief valve is open.

The outflow valves are open.

The outflow valves are closed.

The outflow valves are partly open.

#8. Cabin altitude?

Is actual altitude corrected for sea level pressure.

The pressure altitude at which the pressure in the cabin would occurs in the ISA.

The altitude at which pressure inside and outside of the cabin are the same.

The pressure altitude equating to that in the cabin when at cruising altitude.

#9. Conditioned air?

Is bled from the engines.

Is air that has its pressure and temperature adjusted to make it suitable for use in the cabin.

Is air that has had its humidity, temperature and pressure adjusted to make it suitable for use in the cabin.

Is unsuitable for use in the cabin.

#10. In a bootsrap system the air first?

Passes through a turbine.

Passes through a compressor.

Passes through a dehumidifier.

Passes through a heat exchanger.

#11. If the maximum operating altitude is limited by the cabin pressure, the limiting factor will be?

Maximum pressure differential that the system can achieve.

Maximum pressure differential that the cabin structure can sustain.

Maximum pressure differential that the passengers can tolerate.

Power available from the engines.

#12. The dump valve?

Open the outflow valves.

Open the inflow valves.

Rapidly depressurises the cabin.

Rapidly pressurises the cabin.

#13. Where in a cabin conditioning system is the vapour separator?

After the cold air unit.

After the heat exchanger.

Before the heat exchanger.

Before the turbine.

#14. If cabin pressure becomes lower than ambient?

Outward relief valve closes.

Inward relief valve opens.

Dump valve opens.

The compressor goes into high gear.

#15. If the outflow valve becomes fully closed?

The inward relief valve will open.

The outward relief valve will open.

The cabin skin will rupture.

The safety valve opens when the structural limit is reached.

#16. If QFE is set on the cabin altimeter it will read?

Zero on the ground.

Zero at sea level.

The airfield elevation when on the runway.

The same as the height above sea level when QNH is set.

#17. During a descent the cabin pressure in a pressurised aircraft usually?

Climbs at the same rate as the ambient pressure.

Climbs at a lesser rate than the ambient pressure.

Climbs at a greater rate than the ambient pressure.

Remains constant.

#18. The working cycle of an air cycle machine is?

Induction, compression, power, exhaust.

Induction, cooling, compression, cooling, expansion, exhaust.

Compression, expansion, exhaust.

Induction, compression, cooling, exhaust.

#19. If the outflow valve of a pressurised aircraft malfunctions and opens, when it is cruising at 30000 ft, the cabin pressure will ………, the differential pressure will the cabin ROC will…….. and the cabin pressure altitude will……….?

Increase, increase, decrease, decrease.

Increase, increase, Increase, increase

Decrease, Increase, increase, decrease.

Decrease, decrease, Increase, increase.

#20. Cabin altitude is?

The height of the cabin above the ground.

The height of the cabin in the ISA.

The altitude at which the cabin pressure would occur in the ISA.

The altitude of the cabin above ISA msl.

#21. Pack valves.

Control airflow from the packs.

Control airflow to the packs.

Control bleed air to the packs.

Control bleed air temperature.

#22. If in steady flight the cabin VSI reads 300 fpm?

The pressure will fall to ambient.

The automatic cut-in will operate.

The passengers will suffocate.

The automatic oxygen masks will drop down.

#23. What would the cabin VSI indicate if the cabin pressure suddenly began to decrease in cruise flight?

Positive ROC.

Negative ROC.

Sudden increasing in positive ROC.

Sudden decrease in negative ROC.

#24. The sequence of processes in an air cycle machine is?

Turbine, primary heat exchanger, compressor.

Compressor, turbine, primary heat exchanger.

Compressor, secondary heat exchanger, turbine.

Secondary heat exchanger, compressor, turbine.

#25. The sudden appearance of mist in the cabin indicates?

Slow decompression.

Excessive pressurisation.

Inward relief valve stuck open.

Rapid decompression.

#26. Cabin temperature is controlled?

Manually by the cabin crew.

Manually by the pilot or automatically.

Automatically according to pre-set profiles.

Automatically according to selectable profiles.

#27. The range of differential pressures employed in commercial aircraft is?

3 to 6 psi.

7 to 9 psi.

8 to 15 psi.

7 to 11 psi.

#28. In a manually controlled pressurisation system the rate of change of cabin altitude is controlled by?

The maximum ROC limiter.

The maximum ROD limiter.

The outward vent valve.

The rate change selector.

#29. If an aircraft climbs to 30000 ft at 1500 fpm, while its cabin altitude climbs to 8000 ft at 500 fpm, the cabin pressure will?

Increase.

Decrease gradually over a period of 16 minutes.

Decrease gradually over a period of 20 minutes.

Decrease gradually over a period of 5.33 minutes.

#30. Maximum cabin rate of descent is limited by?

Structural considerations.

Passenger comfort considerations.

Flight crew efficiency considerations.

The physical limitations of the pressurisation system.

#31. Conditioned air is processed to control its?

Temperature, mass flow and humidity.

Temperature, pressure and humidity.

Pressure, mass flow and humidity.

Temperature, pressure and mass flow.

#32. The pressurisation system ensure that?

Both the aircraft and cabin climb to the same pressure altitude.

Both the cabin and the aircraft maintain the same ROC.

As the aircraft climbs to the high pressure altitude, the cabin climbs to a lower one, but at the same ROC.

As the aircraft climbs to high altitude both the ROC and pressure altitude of the cabin are limited to a lower figure.

#33. Operation of the ditching control?

Opens all outflow valves.

Closes all outflow valves.

Opens all outflow and inward relief valves.

Initiates rapid decompression.

#34. If the pressurised cargo holds of a wide body aircraft suddenly decompress at high altitude?

The cabin floor is sufficiently reinforced to prevent collapse.

The cabin will remain pressurised but the floor is likely to be damaged.

The cabin outflow valves will open to equalise pressures above and below the cabin floor.

Vent panels at the sides of the cabin floor will equalise pressure between the cabin and cargo holds.

#35. If after reaching a 32000 ft cruise altitude , the cabin altitude is increased from 6000 ft to 8000 ft, the cabin differential will?

Not be affected.

Increase.

Decrease.

Increase or decrease depending of rate of change.

#36. Modern aircraft pressurisation system employ?

Centrifugal compressors.

Constant outflow and variable inflow.

Constant inflow and variable outflow.

Constant through put.

#37. When the landing gear switch operates, the cabin pressurisation system?

Beings to pressurise the cabin.

Stops pressurising and reduces differential pressure to zero.

Stops pressurising but maintains constant differential pressure.

Switches off the packs.

#38. The mass flow controller?

Varies input mass flow to maintain preset differential pressure

Varies output mass flow to maintain preset differential pressure

Maintains approximately constant mass flow as altitude and engine bleed configurations change.

Maintain a constant mass of air in the cabin.

#39. Inward relief valves open?

Manually prior to ditching.

Automatically prior to ditching.

Automatically when ambient pressure exceeds cabin pressure.

Automatically when cabin pressure exceeds ambient pressure.

#40. Air is compressed in a bootstrap system to ensure that?

The required cabin pressure can be achieved.

There is sufficient mass flow through the cabin for passenger comfort.

To ensure adequate temperature and pressure drop through the turbine.

To ensure that the turbine is driven at the required RPM.

#41. When a pressurised aircraft lands?

Squat switches automatically reduce differential pressure to zero.

Squat switches automatically switch off the packs.

Squat switches automatically increase mass flow to clear the cabin of stale air

The opening of the doors reduces differential pressure to zero.

#42. The air flowing from the turbine of a bootstrap air cooler is?

Higher pressure than that coming out of the compressor.

Higher temperature than that coming out of the compressor.

Lower temperature than that coming out of the compressor.

Lower pressure than that coming out of the compressor.

#43. As a pressurised aircraft climbs to altitude, its cabin pressure will?

Increase to ensure passenger comfort

Decrease at the same rate as ambient

Remain constant

Decrease at a lower rate than amient

#44. Differential pressure is?

The ratio of cabin pressure to amient

The ratio of ambient pressure to cabin pressure

Cain pressure minus ambient

Ambient pressure minus cabin pressure

#45. If the cabin pressure being to increase in straight and level cruise flight the differential pressure will?

Decrease

Increase

Remain constant

Increases of decrease depending on the nature of the failure

#46. The turbine in an air cycle machine

Drivers the compressor to rain the pressure of the air.

Drives the compressor to rain the temperature of the air

Cools the air

Heats the air

#47. What is a boostrap system?

A type of supercharger

A type of oxygen generationgsystem

A type of cabin pressurisation air conditioning system

A type of emergency air comioning system

#48. How does the air flowing out of thembine of a boostrap system compare with that flowing out of the compressor?

Lower pressure and temperate

Lower pressure and higher temperature

Higher pressure and lower temperature

Higher pressure and temperature

#49. The cooling air in a turbo cooler system is?

Engine bleed air

Conditioned air

HP compressed air

Ram air

#50. If the discharge or outflow valves sticks in the closed position?

The cabin with be structurally damaged

The cabin pressure will be constant

The cabin pressure differential will be limited by the safety valve

The packs must be switched off

Finish