Aircraft Environmental Control Systems: 100 MCQs on Cabin Comfort
and Safety
1. What is the typical cabin pressure altitude maintained in commercial aircraft?
a) 5,000 feet
b) 8,000 feet
c) 10,000 feet
d) 12,000 feet
Answer: b) 8,000 feet
2. If the outside air temperature is -50°C at cruising altitude, what is the approximate temperature of
the air after it has been compressed by the engine compressor?
a) 0°C
b) 50°C
c) 100°C
d) 200°C
Answer: d) 200°C
3. How many air changes per hour are typically provided in an aircraft cabin?
a) 5-10
b) 10-15
c) 15-20
d) 20-25
Answer: c) 15-20
4. What percentage of cabin air is typically recirculated in modern aircraft?
a) 10-20%
b) 30-40%
c) 50-60%
d) 70-80%
Answer: c) 50-60%
5. If the aircraft cabin volume is 300 cubic meters and the air change rate is 20 times per hour, what
is the total volume of air circulated in 3 hours?
a) 18,000 cubic meters
b) 6,000 cubic meters
c) 9,000 cubic meters
d) 12,000 cubic meters
Answer: a) 18,000 cubic meters
6. What is the typical relative humidity in an aircraft cabin during cruise?
a) 5-10%
b) 10-20%
c) 30-40%
d) 50-60%
Answer: b) 10-20%
7. If the cabin altitude is 8,000 feet, what is the approximate air pressure inside the cabin?
a) 101.3 kPa
b) 75.2 kPa
c) 54.7 kPa
d) 34.5 kPa
Answer: b) 75.2 kPa
8. How many pounds per square inch (psi) is the typical pressure differential between the cabin and
the outside air at cruising altitude?
a) 3-4 psi
b) 5-6 psi
c) 7-8 psi
d) 9-10 psi
Answer: c) 7-8 psi
9. If the aircraft is cruising at 35,000 feet with a cabin altitude of 8,000 feet, what is the pressure
differential in psi?
a) 5.2 psi
b) 6.8 psi
c) 8.4 psi
d) 9.6 psi
Answer: b) 6.8 psi
10. What is the typical air flow rate per passenger in cubic feet per minute (CFM)?
a) 5 CFM
b) 10 CFM
c) 15 CFM
d) 20 CFM
Answer: c) 15 CFM
11. If an aircraft has 200 passengers and requires 15 CFM per passenger, what is the total air flow
rate needed?
a) 2,000 CFM
b) 3,000 CFM
c) 4,000 CFM
d) 5,000 CFM
Answer: b) 3,000 CFM
12. What is the maximum cabin altitude allowed by FAA regulations?
a) 6,000 feet
b) 8,000 feet
c) 10,000 feet
d) 12,000 feet
Answer: b) 8,000 feet
13. If the outside air temperature is -60°C and the desired cabin temperature is 22°C, what is the
temperature difference that the air conditioning system must overcome?
a) 62°C
b) 72°C
c) 82°C
d) 92°C
Answer: c) 82°C
14. What percentage of fresh air is typically introduced into the cabin during each air cycle?
a) 20%
b) 30%
c) 40%
d) 50%
Answer: d) 50%
15. If the cabin pressure is 75 kPa and the outside pressure is 25 kPa, what is the pressure ratio?
a) 2:1
b) 3:1
c) 4:1
d) 5:1
Answer: b) 3:1
16. How many microns in size are the particles typically filtered out by HEPA filters in aircraft?
a) 0.1 microns
b) 0.3 microns
c) 0.5 microns
d) 1.0 microns
Answer: b) 0.3 microns
17. If the aircraft is descending at 300 feet per minute, how long will it take to change the cabin
altitude from 8,000 feet to 5,000 feet?
a) 5 minutes
b) 10 minutes
c) 15 minutes
d) 20 minutes
Answer: b) 10 minutes
18. What is the typical ozone concentration limit in the aircraft cabin according to FAA regulations?
a) 0.1 ppm
b) 0.25 ppm
c) 0.5 ppm
d) 1.0 ppm
Answer: a) 0.1 ppm
19. If the air conditioning pack delivers 100 kg/min of air at 5°C and mixes with 100 kg/min of
recirculated air at 25°C, what is the resulting temperature?
a) 10°C
b) 15°C
c) 20°C
d) 30°C
Answer: b) 15°C
20. What is the typical CO2 concentration in an aircraft cabin during cruise?
a) 500-1000 ppm
b) 1000-1500 ppm
c) 1500-2000 ppm
d) 2000-2500 ppm
Answer: b) 1000-1500 ppm
21. If the cabin volume is 250 cubic meters and the air change rate is 18 times per hour, what is the
total air flow rate in cubic meters per minute?
a) 45 m³/min
b) 60 m³/min
c) 75 m³/min
d) 90 m³/min
Answer: c) 75 m³/min
22. What is the typical temperature range maintained in the aircraft cabin?
a) 18-22°C
b) 20-24°C
c) 22-26°C
d) 24-28°C
Answer: b) 20-24°C
23. If the outside air temperature is -40°C and the air is compressed to 4 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 100°C
c) 150°C
d) 200°C
Answer: c) 150°C
24. How many pounds of air per minute are typically required for each passenger in an aircraft?
a) 0.5 lbs/min
b) 1.0 lbs/min
c) 1.5 lbs/min
d) 2.0 lbs/min
Answer: b) 1.0 lbs/min
25. If an aircraft has 300 passengers and requires 1.0 lbs/min of air per passenger, what is the total
air requirement in pounds per hour?
a) 9,000 lbs/hr
b) 12,000 lbs/hr
c) 15,000 lbs/hr
d) 18,000 lbs/hr
Answer: d) 18,000 lbs/hr
26. What is the typical efficiency of HEPA filters used in aircraft cabins?
a) 90%
b) 95%
c) 99%
d) 99.97%
Answer: d) 99.97%
27. If the cabin pressure is 75 kPa and the aircraft descends to an altitude where the outside pressure
is 90 kPa, what is the new pressure differential?
a) 5 kPa
b) 10 kPa
c) 15 kPa
d) 20 kPa
Answer: c) 15 kPa
28. What is the maximum allowed concentration of carbon monoxide (CO) in the aircraft cabin?
a) 5 ppm
b) 10 ppm
c) 15 ppm
d) 20 ppm
Answer: d) 20 ppm
29. If the air conditioning system can lower the air temperature by 5°C per minute, how long will it
take to cool the cabin from 30°C to 22°C?
a) 1 minute
b) 1.6 minutes
c) 2 minutes
d) 2.4 minutes
Answer: b) 1.6 minutes
30. What is the typical range of air velocity in the aircraft cabin to maintain passenger comfort?
a) 0.1-0.3 m/s
b) 0.3-0.5 m/s
c) 0.5-0.7 m/s
d) 0.7-0.9 m/s
Answer: a) 0.1-0.3 m/s
31. If the aircraft is climbing at 500 feet per minute, how long will it take for the cabin altitude to
change from 2,000 feet to 8,000 feet?
a) 8 minutes
b) 10 minutes
c) 12 minutes
d) 14 minutes
Answer: c) 12 minutes
32. What percentage of cabin air is typically filtered through HEPA filters?
a) 25%
b) 50%
c) 75%
d) 100%
Answer: d) 100%
33. If the outside air temperature is -55°C and the air is heated to 180°C by compression, what is the
temperature change?
a) 205°C
b) 225°C
c) 235°C
d) 245°C
Answer: c) 235°C
34. What is the typical pressurization rate during aircraft climb?
a) 300-500 ft/min
b) 500-700 ft/min
c) 700-900 ft/min
d) 900-1100 ft/min
Answer: a) 300-500 ft/min
35. If the cabin volume is 400 cubic meters and the air change rate is 16 times per hour, what is the
total air flow rate in cubic meters per hour?
a) 4,800 m³/hr
b) 5,600 m³/hr
c) 6,400 m³/hr
d) 7,200 m³/hr
Answer: c) 6,400 m³/hr
36. What is the typical range of relative humidity in the flight deck?
a) 5-10%
b) 10-15%
c) 15-20%
d) 20-25%
Answer: c) 15-20%
37. If the aircraft is flying at 39,000 feet with a cabin altitude of 6,000 feet, what is the pressure
differential in psi? (Assume 14.7 psi at sea level)
a) 7.2 psi
b) 7.8 psi
c) 8.4 psi
d) 9.0 psi
Answer: c) 8.4 psi
38. How many air changes per hour are typically provided in the flight deck?
a) 10-15
b) 20-25
c) 30-35
d) 40-45
Answer: b) 20-25
39. If the air conditioning system can heat the air at a rate of 3°C per minute, how long will it take to
warm the cabin from 15°C to 24°C?
a) 2 minutes
b) 3 minutes
c) 4 minutes
d) 5 minutes
Answer: b) 3 minutes
40. What is the typical maximum cabin differential pressure for most commercial aircraft?
a) 6.5-7.5 psi
b) 7.5-8.5 psi
c) 8.5-9.5 psi
d) 9.5-10.5 psi
Answer: b) 7.5-8.5 psi
41. If the aircraft has 250 passengers and the air flow rate is 20 CFM per passenger, what is the total
air flow rate in cubic meters per hour? (1 CFM ≈ 1.699 m³/hr)
a) 76,455 m³/hr
b) 84,950 m³/hr
c) 93,445 m³/hr
d) 101,940 m³/hr
Answer: b) 84,950 m³/hr
42. What is the typical pressure altitude inside the cabin when the aircraft is at its maximum
operating altitude?
a) 5,000-6,000 feet
b) 6,000-7,000 feet
c) 7,000-8,000 feet
d) 8,000-9,000 feet
Answer: c) 7,000-8,000 feet
43. If the outside air temperature is -50°C and the air is compressed to 3 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 75°C
c) 100°C
d) 125°C
Answer: c) 100°C
44. What is the typical air flow rate per square meter of cabin floor area?
a) 1-2 L/s/m²
b) 2-3 L/s/m²
c) 3-4 L/s/m²
d) 4-5 L/s/m²
Answer: b) 2-3 L/s/m²
45. If the cabin floor area is 200 m² and the air flow rate is 2.5 L/s/m², what is the total air flow rate
in cubic meters per hour?
a) 1,500 m³/hr
b) 1,800 m³/hr
c) 2,100 m³/hr
d) 2,400 m³/hr
Answer: b) 1,800 m³/hr
46. What is the typical maximum rate of cabin pressure change during normal operations?
a) 200 ft/min
b) 300 ft/min
c) 400 ft/min
d) 500 ft/min
Answer: c) 400 ft/min
47. If the aircraft descends from 35,000 feet to 10,000 feet in 15 minutes, what is the average rate of
descent?
a) 1,000 ft/min
b) 1,500 ft/min
c) 1,667 ft/min
d) 2,000 ft/min
Answer: c) 1,667 ft/min
48. What is the typical temperature of air exiting the air conditioning packs?
a) 0-5°C
b) 5-10°C
c) 10-15°C
d) 15-20°C
Answer: a) 0-5°C
49. If the air conditioning pack delivers 80 kg/min of air at 2°C and mixes with 120 kg/min of
recirculated air at 23°C, what is the resulting temperature?
a) 12°C
b) 14°C
c) 16°C
d) 18°C
Answer: b) 14°C
50. What is the typical range of air pressure in the aircraft cabin during cruise?
a) 70-75 kPa
b) 75-80 kPa
c) 80-85 kPa
d) 85-90 kPa
Answer: b) 75-80 kPa
51. If the cabin volume is 350 cubic meters and the air change rate is 17 times per hour, what is the
total air flow rate in liters per second?
a) 1,458 L/s
b) 1,653 L/s
c) 1,847 L/s
d) 2,042 L/s
Answer: b) 1,653 L/s
How many microns in size are the particles typically filtered out by HEPA filters in aircraft?
a) 0.1 microns
b) 0.3 microns
c) 0.5 microns
d) 1.0 microns
Answer: b) 0.3 microns
17. If the aircraft is descending at 300 feet per minute, how long will it take to change the cabin
altitude from 8,000 feet to 5,000 feet?
a) 5 minutes
b) 10 minutes
c) 15 minutes
d) 20 minutes
Answer: b) 10 minutes
18. What is the typical ozone concentration limit in the aircraft cabin according to FAA regulations?
a) 0.1 ppm
b) 0.25 ppm
c) 0.5 ppm
d) 1.0 ppm
Answer: a) 0.1 ppm
19. If the air conditioning pack delivers 100 kg/min of air at 5°C and mixes with 100 kg/min of
recirculated air at 25°C, what is the resulting temperature?
a) 10°C
b) 15°C
c) 20°C
d) 30°C
Answer: b) 15°C
20. What is the typical CO2 concentration in an aircraft cabin during cruise?
a) 500-1000 ppm
b) 1000-1500 ppm
c) 1500-2000 ppm
d) 2000-2500 ppm
Answer: b) 1000-1500 ppm
21. If the cabin volume is 250 cubic meters and the air change rate is 18 times per hour, what is the
total air flow rate in cubic meters per minute?
a) 45 m³/min
b) 60 m³/min
c) 75 m³/min
d) 90 m³/min
Answer: c) 75 m³/min
22. What is the typical temperature range maintained in the aircraft cabin?
a) 18-22°C
b) 20-24°C
c) 22-26°C
d) 24-28°C
Answer: b) 20-24°C
23. If the outside air temperature is -40°C and the air is compressed to 4 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 100°C
c) 150°C
d) 200°C
Answer: c) 150°C
24. How many pounds of air per minute are typically required for each passenger in an aircraft?
a) 0.5 lbs/min
b) 1.0 lbs/min
c) 1.5 lbs/min
d) 2.0 lbs/min
Answer: b) 1.0 lbs/min
25. If an aircraft has 300 passengers and requires 1.0 lbs/min of air per passenger, what is the total
air requirement in pounds per hour?
a) 9,000 lbs/hr
b) 12,000 lbs/hr
c) 15,000 lbs/hr
d) 18,000 lbs/hr
Answer: d) 18,000 lbs/hr
26. What is the typical efficiency of HEPA filters used in aircraft cabins?
a) 90%
b) 95%
c) 99%
d) 99.97%
Answer: d) 99.97%
27. If the cabin pressure is 75 kPa and the aircraft descends to an altitude where the outside pressure
is 90 kPa, what is the new pressure differential?
a) 5 kPa
b) 10 kPa
c) 15 kPa
d) 20 kPa
Answer: c) 15 kPa
28. What is the maximum allowed concentration of carbon monoxide (CO) in the aircraft cabin?
a) 5 ppm
b) 10 ppm
c) 15 ppm
d) 20 ppm
Answer: d) 20 ppm
29. If the air conditioning system can lower the air temperature by 5°C per minute, how long will it
take to cool the cabin from 30°C to 22°C?
a) 1 minute
b) 1.6 minutes
c) 2 minutes
d) 2.4 minutes
Answer: b) 1.6 minutes
30. What is the typical range of air velocity in the aircraft cabin to maintain passenger comfort?
a) 0.1-0.3 m/s
b) 0.3-0.5 m/s
c) 0.5-0.7 m/s
d) 0.7-0.9 m/s
Answer: a) 0.1-0.3 m/s
31. If the aircraft is climbing at 500 feet per minute, how long will it take for the cabin altitude to
change from 2,000 feet to 8,000 feet?
a) 8 minutes
b) 10 minutes
c) 12 minutes
d) 14 minutes
Answer: c) 12 minutes
32. What percentage of cabin air is typically filtered through HEPA filters?
a) 25%
b) 50%
c) 75%
d) 100%
Answer: d) 100%
33. If the outside air temperature is -55°C and the air is heated to 180°C by compression, what is the
temperature change?
a) 205°C
b) 225°C
c) 235°C
d) 245°C
Answer: c) 235°C
34. What is the typical pressurization rate during aircraft climb?
a) 300-500 ft/min
b) 500-700 ft/min
c) 700-900 ft/min
d) 900-1100 ft/min
Answer: a) 300-500 ft/min
35. If the cabin volume is 400 cubic meters and the air change rate is 16 times per hour, what is the
total air flow rate in cubic meters per hour?
a) 4,800 m³/hr
b) 5,600 m³/hr
c) 6,400 m³/hr
d) 7,200 m³/hr
Answer: c) 6,400 m³/hr
36. What is the typical range of relative humidity in the flight deck?
a) 5-10%
b) 10-15%
c) 15-20%
d) 20-25%
Answer: c) 15-20%
37. If the aircraft is flying at 39,000 feet with a cabin altitude of 6,000 feet, what is the pressure
differential in psi? (Assume 14.7 psi at sea level)
a) 7.2 psi
b) 7.8 psi
c) 8.4 psi
d) 9.0 psi
Answer: c) 8.4 psi
38. How many air changes per hour are typically provided in the flight deck?
a) 10-15
b) 20-25
c) 30-35
d) 40-45
Answer: b) 20-25
39. If the air conditioning system can heat the air at a rate of 3°C per minute, how long will it take to
warm the cabin from 15°C to 24°C?
a) 2 minutes
b) 3 minutes
c) 4 minutes
d) 5 minutes
Answer: b) 3 minutes
40. What is the typical maximum cabin differential pressure for most commercial aircraft?
a) 6.5-7.5 psi
b) 7.5-8.5 psi
c) 8.5-9.5 psi
d) 9.5-10.5 psi
Answer: b) 7.5-8.5 psi
41. If the aircraft has 250 passengers and the air flow rate is 20 CFM per passenger, what is the total
air flow rate in cubic meters per hour? (1 CFM ≈ 1.699 m³/hr)
a) 76,455 m³/hr
b) 84,950 m³/hr
c) 93,445 m³/hr
d) 101,940 m³/hr
Answer: b) 84,950 m³/hr
42. What is the typical pressure altitude inside the cabin when the aircraft is at its maximum
operating altitude?
a) 5,000-6,000 feet
b) 6,000-7,000 feet
c) 7,000-8,000 feet
d) 8,000-9,000 feet
Answer: c) 7,000-8,000 feet
43. If the outside air temperature is -50°C and the air is compressed to 3 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 75°C
c) 100°C
d) 125°C
Answer: c) 100°C
44. What is the typical air flow rate per square meter of cabin floor area?
a) 1-2 L/s/m²
b) 2-3 L/s/m²
c) 3-4 L/s/m²
d) 4-5 L/s/m²
Answer: b) 2-3 L/s/m²
45. If the cabin floor area is 200 m² and the air flow rate is 2.5 L/s/m², what is the total air flow rate
in cubic meters per hour?
a) 1,500 m³/hr
b) 1,800 m³/hr
c) 2,100 m³/hr
d) 2,400 m³/hr
Answer: b) 1,800 m³/hr
46. What is the typical maximum rate of cabin pressure change during normal operations?
a) 200 ft/min
b) 300 ft/min
c) 400 ft/min
d) 500 ft/min
Answer: c) 400 ft/min
47. If the aircraft descends from 35,000 feet to 10,000 feet in 15 minutes, what is the average rate of
descent?
a) 1,000 ft/min
b) 1,500 ft/min
c) 1,667 ft/min
d) 2,000 ft/min
Answer: c) 1,667 ft/min
48. What is the typical temperature of air exiting the air conditioning packs?
a) 0-5°C
b) 5-10°C
c) 10-15°C
d) 15-20°C
Answer: a) 0-5°C
49. If the air conditioning pack delivers 80 kg/min of air at 2°C and mixes with 120 kg/min of
recirculated air at 23°C, what is the resulting temperature?
a) 12°C
b) 14°C
c) 16°C
d) 18°C
Answer: b) 14°C
50. What is the typical range of air pressure in the aircraft cabin during cruise?
a) 70-75 kPa
b) 75-80 kPa
c) 80-85 kPa
d) 85-90 kPa
Answer: b) 75-80 kPa
51. If the cabin volume is 350 cubic meters and the air change rate is 17 times per hour, what is the
total air flow rate in liters per second?
a) 1,458 L/s
b) 1,653 L/s
c) 1,847 L/s
d) 2,042 L/s
Answer: b) 1,653 L/s
How many microns in size are the particles typically filtered out by HEPA filters in aircraft?
a) 0.1 microns
b) 0.3 microns
c) 0.5 microns
d) 1.0 microns
Answer: b) 0.3 microns
17. If the aircraft is descending at 300 feet per minute, how long will it take to change the cabin
altitude from 8,000 feet to 5,000 feet?
a) 5 minutes
b) 10 minutes
c) 15 minutes
d) 20 minutes
Answer: b) 10 minutes
18. What is the typical ozone concentration limit in the aircraft cabin according to FAA regulations?
a) 0.1 ppm
b) 0.25 ppm
c) 0.5 ppm
d) 1.0 ppm
Answer: a) 0.1 ppm
19. If the air conditioning pack delivers 100 kg/min of air at 5°C and mixes with 100 kg/min of
recirculated air at 25°C, what is the resulting temperature?
a) 10°C
b) 15°C
c) 20°C
d) 30°C
Answer: b) 15°C
20. What is the typical CO2 concentration in an aircraft cabin during cruise?
a) 500-1000 ppm
b) 1000-1500 ppm
c) 1500-2000 ppm
d) 2000-2500 ppm
Answer: b) 1000-1500 ppm
21. If the cabin volume is 250 cubic meters and the air change rate is 18 times per hour, what is the
total air flow rate in cubic meters per minute?
a) 45 m³/min
b) 60 m³/min
c) 75 m³/min
d) 90 m³/min
Answer: c) 75 m³/min
22. What is the typical temperature range maintained in the aircraft cabin?
a) 18-22°C
b) 20-24°C
c) 22-26°C
d) 24-28°C
Answer: b) 20-24°C
23. If the outside air temperature is -40°C and the air is compressed to 4 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 100°C
c) 150°C
d) 200°C
Answer: c) 150°C
24. How many pounds of air per minute are typically required for each passenger in an aircraft?
a) 0.5 lbs/min
b) 1.0 lbs/min
c) 1.5 lbs/min
d) 2.0 lbs/min
Answer: b) 1.0 lbs/min
25. If an aircraft has 300 passengers and requires 1.0 lbs/min of air per passenger, what is the total
air requirement in pounds per hour?
a) 9,000 lbs/hr
b) 12,000 lbs/hr
c) 15,000 lbs/hr
d) 18,000 lbs/hr
Answer: d) 18,000 lbs/hr
26. What is the typical efficiency of HEPA filters used in aircraft cabins?
a) 90%
b) 95%
c) 99%
d) 99.97%
Answer: d) 99.97%
27. If the cabin pressure is 75 kPa and the aircraft descends to an altitude where the outside pressure
is 90 kPa, what is the new pressure differential?
a) 5 kPa
b) 10 kPa
c) 15 kPa
d) 20 kPa
Answer: c) 15 kPa
28. What is the maximum allowed concentration of carbon monoxide (CO) in the aircraft cabin?
a) 5 ppm
b) 10 ppm
c) 15 ppm
d) 20 ppm
Answer: d) 20 ppm
29. If the air conditioning system can lower the air temperature by 5°C per minute, how long will it
take to cool the cabin from 30°C to 22°C?
a) 1 minute
b) 1.6 minutes
c) 2 minutes
d) 2.4 minutes
Answer: b) 1.6 minutes
30. What is the typical range of air velocity in the aircraft cabin to maintain passenger comfort?
a) 0.1-0.3 m/s
b) 0.3-0.5 m/s
c) 0.5-0.7 m/s
d) 0.7-0.9 m/s
Answer: a) 0.1-0.3 m/s
31. If the aircraft is climbing at 500 feet per minute, how long will it take for the cabin altitude to
change from 2,000 feet to 8,000 feet?
a) 8 minutes
b) 10 minutes
c) 12 minutes
d) 14 minutes
Answer: c) 12 minutes
32. What percentage of cabin air is typically filtered through HEPA filters?
a) 25%
b) 50%
c) 75%
d) 100%
Answer: d) 100%
33. If the outside air temperature is -55°C and the air is heated to 180°C by compression, what is the
temperature change?
a) 205°C
b) 225°C
c) 235°C
d) 245°C
Answer: c) 235°C
34. What is the typical pressurization rate during aircraft climb?
a) 300-500 ft/min
b) 500-700 ft/min
c) 700-900 ft/min
d) 900-1100 ft/min
Answer: a) 300-500 ft/min
35. If the cabin volume is 400 cubic meters and the air change rate is 16 times per hour, what is the
total air flow rate in cubic meters per hour?
a) 4,800 m³/hr
b) 5,600 m³/hr
c) 6,400 m³/hr
d) 7,200 m³/hr
Answer: c) 6,400 m³/hr
36. What is the typical range of relative humidity in the flight deck?
a) 5-10%
b) 10-15%
c) 15-20%
d) 20-25%
Answer: c) 15-20%
37. If the aircraft is flying at 39,000 feet with a cabin altitude of 6,000 feet, what is the pressure
differential in psi? (Assume 14.7 psi at sea level)
a) 7.2 psi
b) 7.8 psi
c) 8.4 psi
d) 9.0 psi
Answer: c) 8.4 psi
38. How many air changes per hour are typically provided in the flight deck?
a) 10-15
b) 20-25
c) 30-35
d) 40-45
Answer: b) 20-25
39. If the air conditioning system can heat the air at a rate of 3°C per minute, how long will it take to
warm the cabin from 15°C to 24°C?
a) 2 minutes
b) 3 minutes
c) 4 minutes
d) 5 minutes
Answer: b) 3 minutes
40. What is the typical maximum cabin differential pressure for most commercial aircraft?
a) 6.5-7.5 psi
b) 7.5-8.5 psi
c) 8.5-9.5 psi
d) 9.5-10.5 psi
Answer: b) 7.5-8.5 psi
41. If the aircraft has 250 passengers and the air flow rate is 20 CFM per passenger, what is the total
air flow rate in cubic meters per hour? (1 CFM ≈ 1.699 m³/hr)
a) 76,455 m³/hr
b) 84,950 m³/hr
c) 93,445 m³/hr
d) 101,940 m³/hr
Answer: b) 84,950 m³/hr
42. What is the typical pressure altitude inside the cabin when the aircraft is at its maximum
operating altitude?
a) 5,000-6,000 feet
b) 6,000-7,000 feet
c) 7,000-8,000 feet
d) 8,000-9,000 feet
Answer: c) 7,000-8,000 feet
43. If the outside air temperature is -50°C and the air is compressed to 3 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 75°C
c) 100°C
d) 125°C
Answer: c) 100°C
44. What is the typical air flow rate per square meter of cabin floor area?
a) 1-2 L/s/m²
b) 2-3 L/s/m²
c) 3-4 L/s/m²
d) 4-5 L/s/m²
Answer: b) 2-3 L/s/m²
45. If the cabin floor area is 200 m² and the air flow rate is 2.5 L/s/m², what is the total air flow rate
in cubic meters per hour?
a) 1,500 m³/hr
b) 1,800 m³/hr
c) 2,100 m³/hr
d) 2,400 m³/hr
Answer: b) 1,800 m³/hr
46. What is the typical maximum rate of cabin pressure change during normal operations?
a) 200 ft/min
b) 300 ft/min
c) 400 ft/min
d) 500 ft/min
Answer: c) 400 ft/min
47. If the aircraft descends from 35,000 feet to 10,000 feet in 15 minutes, what is the average rate of
descent?
a) 1,000 ft/min
b) 1,500 ft/min
c) 1,667 ft/min
d) 2,000 ft/min
Answer: c) 1,667 ft/min
48. What is the typical temperature of air exiting the air conditioning packs?
a) 0-5°C
b) 5-10°C
c) 10-15°C
d) 15-20°C
Answer: a) 0-5°C
49. If the air conditioning pack delivers 80 kg/min of air at 2°C and mixes with 120 kg/min of
recirculated air at 23°C, what is the resulting temperature?
a) 12°C
b) 14°C
c) 16°C
d) 18°C
Answer: b) 14°C
50. What is the typical range of air pressure in the aircraft cabin during cruise?
a) 70-75 kPa
b) 75-80 kPa
c) 80-85 kPa
d) 85-90 kPa
Answer: b) 75-80 kPa
51. If the cabin volume is 350 cubic meters and the air change rate is 17 times per hour, what is the
total air flow rate in liters per second?
a) 1,458 L/s
b) 1,653 L/s
c) 1,847 L/s
d) 2,042 L/s
Answer: b) 1,653 L/s
How many microns in size are the particles typically filtered out by HEPA filters in aircraft?
a) 0.1 microns
b) 0.3 microns
c) 0.5 microns
d) 1.0 microns
Answer: b) 0.3 microns
17. If the aircraft is descending at 300 feet per minute, how long will it take to change the cabin
altitude from 8,000 feet to 5,000 feet?
a) 5 minutes
b) 10 minutes
c) 15 minutes
d) 20 minutes
Answer: b) 10 minutes
18. What is the typical ozone concentration limit in the aircraft cabin according to FAA regulations?
a) 0.1 ppm
b) 0.25 ppm
c) 0.5 ppm
d) 1.0 ppm
Answer: a) 0.1 ppm
19. If the air conditioning pack delivers 100 kg/min of air at 5°C and mixes with 100 kg/min of
recirculated air at 25°C, what is the resulting temperature?
a) 10°C
b) 15°C
c) 20°C
d) 30°C
Answer: b) 15°C
20. What is the typical CO2 concentration in an aircraft cabin during cruise?
a) 500-1000 ppm
b) 1000-1500 ppm
c) 1500-2000 ppm
d) 2000-2500 ppm
Answer: b) 1000-1500 ppm
21. If the cabin volume is 250 cubic meters and the air change rate is 18 times per hour, what is the
total air flow rate in cubic meters per minute?
a) 45 m³/min
b) 60 m³/min
c) 75 m³/min
d) 90 m³/min
Answer: c) 75 m³/min
22. What is the typical temperature range maintained in the aircraft cabin?
a) 18-22°C
b) 20-24°C
c) 22-26°C
d) 24-28°C
Answer: b) 20-24°C
23. If the outside air temperature is -40°C and the air is compressed to 4 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 100°C
c) 150°C
d) 200°C
Answer: c) 150°C
24. How many pounds of air per minute are typically required for each passenger in an aircraft?
a) 0.5 lbs/min
b) 1.0 lbs/min
c) 1.5 lbs/min
d) 2.0 lbs/min
Answer: b) 1.0 lbs/min
25. If an aircraft has 300 passengers and requires 1.0 lbs/min of air per passenger, what is the total
air requirement in pounds per hour?
a) 9,000 lbs/hr
b) 12,000 lbs/hr
c) 15,000 lbs/hr
d) 18,000 lbs/hr
Answer: d) 18,000 lbs/hr
26. What is the typical efficiency of HEPA filters used in aircraft cabins?
a) 90%
b) 95%
c) 99%
d) 99.97%
Answer: d) 99.97%
27. If the cabin pressure is 75 kPa and the aircraft descends to an altitude where the outside pressure
is 90 kPa, what is the new pressure differential?
a) 5 kPa
b) 10 kPa
c) 15 kPa
d) 20 kPa
Answer: c) 15 kPa
28. What is the maximum allowed concentration of carbon monoxide (CO) in the aircraft cabin?
a) 5 ppm
b) 10 ppm
c) 15 ppm
d) 20 ppm
Answer: d) 20 ppm
29. If the air conditioning system can lower the air temperature by 5°C per minute, how long will it
take to cool the cabin from 30°C to 22°C?
a) 1 minute
b) 1.6 minutes
c) 2 minutes
d) 2.4 minutes
Answer: b) 1.6 minutes
30. What is the typical range of air velocity in the aircraft cabin to maintain passenger comfort?
a) 0.1-0.3 m/s
b) 0.3-0.5 m/s
c) 0.5-0.7 m/s
d) 0.7-0.9 m/s
Answer: a) 0.1-0.3 m/s
31. If the aircraft is climbing at 500 feet per minute, how long will it take for the cabin altitude to
change from 2,000 feet to 8,000 feet?
a) 8 minutes
b) 10 minutes
c) 12 minutes
d) 14 minutes
Answer: c) 12 minutes
32. What percentage of cabin air is typically filtered through HEPA filters?
a) 25%
b) 50%
c) 75%
d) 100%
Answer: d) 100%
33. If the outside air temperature is -55°C and the air is heated to 180°C by compression, what is the
temperature change?
a) 205°C
b) 225°C
c) 235°C
d) 245°C
Answer: c) 235°C
34. What is the typical pressurization rate during aircraft climb?
a) 300-500 ft/min
b) 500-700 ft/min
c) 700-900 ft/min
d) 900-1100 ft/min
Answer: a) 300-500 ft/min
35. If the cabin volume is 400 cubic meters and the air change rate is 16 times per hour, what is the
total air flow rate in cubic meters per hour?
a) 4,800 m³/hr
b) 5,600 m³/hr
c) 6,400 m³/hr
d) 7,200 m³/hr
Answer: c) 6,400 m³/hr
36. What is the typical range of relative humidity in the flight deck?
a) 5-10%
b) 10-15%
c) 15-20%
d) 20-25%
Answer: c) 15-20%
37. If the aircraft is flying at 39,000 feet with a cabin altitude of 6,000 feet, what is the pressure
differential in psi? (Assume 14.7 psi at sea level)
a) 7.2 psi
b) 7.8 psi
c) 8.4 psi
d) 9.0 psi
Answer: c) 8.4 psi
38. How many air changes per hour are typically provided in the flight deck?
a) 10-15
b) 20-25
c) 30-35
d) 40-45
Answer: b) 20-25
39. If the air conditioning system can heat the air at a rate of 3°C per minute, how long will it take to
warm the cabin from 15°C to 24°C?
a) 2 minutes
b) 3 minutes
c) 4 minutes
d) 5 minutes
Answer: b) 3 minutes
40. What is the typical maximum cabin differential pressure for most commercial aircraft?
a) 6.5-7.5 psi
b) 7.5-8.5 psi
c) 8.5-9.5 psi
d) 9.5-10.5 psi
Answer: b) 7.5-8.5 psi
41. If the aircraft has 250 passengers and the air flow rate is 20 CFM per passenger, what is the total
air flow rate in cubic meters per hour? (1 CFM ≈ 1.699 m³/hr)
a) 76,455 m³/hr
b) 84,950 m³/hr
c) 93,445 m³/hr
d) 101,940 m³/hr
Answer: b) 84,950 m³/hr
42. What is the typical pressure altitude inside the cabin when the aircraft is at its maximum
operating altitude?
a) 5,000-6,000 feet
b) 6,000-7,000 feet
c) 7,000-8,000 feet
d) 8,000-9,000 feet
Answer: c) 7,000-8,000 feet
43. If the outside air temperature is -50°C and the air is compressed to 3 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 75°C
c) 100°C
d) 125°C
Answer: c) 100°C
44. What is the typical air flow rate per square meter of cabin floor area?
a) 1-2 L/s/m²
b) 2-3 L/s/m²
c) 3-4 L/s/m²
d) 4-5 L/s/m²
Answer: b) 2-3 L/s/m²
45. If the cabin floor area is 200 m² and the air flow rate is 2.5 L/s/m², what is the total air flow rate
in cubic meters per hour?
a) 1,500 m³/hr
b) 1,800 m³/hr
c) 2,100 m³/hr
d) 2,400 m³/hr
Answer: b) 1,800 m³/hr
46. What is the typical maximum rate of cabin pressure change during normal operations?
a) 200 ft/min
b) 300 ft/min
c) 400 ft/min
d) 500 ft/min
Answer: c) 400 ft/min
47. If the aircraft descends from 35,000 feet to 10,000 feet in 15 minutes, what is the average rate of
descent?
a) 1,000 ft/min
b) 1,500 ft/min
c) 1,667 ft/min
d) 2,000 ft/min
Answer: c) 1,667 ft/min
48. What is the typical temperature of air exiting the air conditioning packs?
a) 0-5°C
b) 5-10°C
c) 10-15°C
d) 15-20°C
Answer: a) 0-5°C
49. If the air conditioning pack delivers 80 kg/min of air at 2°C and mixes with 120 kg/min of
recirculated air at 23°C, what is the resulting temperature?
a) 12°C
b) 14°C
c) 16°C
d) 18°C
Answer: b) 14°C
50. What is the typical range of air pressure in the aircraft cabin during cruise?
a) 70-75 kPa
b) 75-80 kPa
c) 80-85 kPa
d) 85-90 kPa
Answer: b) 75-80 kPa
51. If the cabin volume is 350 cubic meters and the air change rate is 17 times per hour, what is the
total air flow rate in liters per second?
a) 1,458 L/s
b) 1,653 L/s
c) 1,847 L/s
d) 2,042 L/s
Answer: b) 1,653 L/s
How many microns in size are the particles typically filtered out by HEPA filters in aircraft?
a) 0.1 microns
b) 0.3 microns
c) 0.5 microns
d) 1.0 microns
Answer: b) 0.3 microns
17. If the aircraft is descending at 300 feet per minute, how long will it take to change the cabin
altitude from 8,000 feet to 5,000 feet?
a) 5 minutes
b) 10 minutes
c) 15 minutes
d) 20 minutes
Answer: b) 10 minutes
18. What is the typical ozone concentration limit in the aircraft cabin according to FAA regulations?
a) 0.1 ppm
b) 0.25 ppm
c) 0.5 ppm
d) 1.0 ppm
Answer: a) 0.1 ppm
19. If the air conditioning pack delivers 100 kg/min of air at 5°C and mixes with 100 kg/min of
recirculated air at 25°C, what is the resulting temperature?
a) 10°C
b) 15°C
c) 20°C
d) 30°C
Answer: b) 15°C
20. What is the typical CO2 concentration in an aircraft cabin during cruise?
a) 500-1000 ppm
b) 1000-1500 ppm
c) 1500-2000 ppm
d) 2000-2500 ppm
Answer: b) 1000-1500 ppm
21. If the cabin volume is 250 cubic meters and the air change rate is 18 times per hour, what is the
total air flow rate in cubic meters per minute?
a) 45 m³/min
b) 60 m³/min
c) 75 m³/min
d) 90 m³/min
Answer: c) 75 m³/min
22. What is the typical temperature range maintained in the aircraft cabin?
a) 18-22°C
b) 20-24°C
c) 22-26°C
d) 24-28°C
Answer: b) 20-24°C
23. If the outside air temperature is -40°C and the air is compressed to 4 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 100°C
c) 150°C
d) 200°C
Answer: c) 150°C
24. How many pounds of air per minute are typically required for each passenger in an aircraft?
a) 0.5 lbs/min
b) 1.0 lbs/min
c) 1.5 lbs/min
d) 2.0 lbs/min
Answer: b) 1.0 lbs/min
25. If an aircraft has 300 passengers and requires 1.0 lbs/min of air per passenger, what is the total
air requirement in pounds per hour?
a) 9,000 lbs/hr
b) 12,000 lbs/hr
c) 15,000 lbs/hr
d) 18,000 lbs/hr
Answer: d) 18,000 lbs/hr
26. What is the typical efficiency of HEPA filters used in aircraft cabins?
a) 90%
b) 95%
c) 99%
d) 99.97%
Answer: d) 99.97%
27. If the cabin pressure is 75 kPa and the aircraft descends to an altitude where the outside pressure
is 90 kPa, what is the new pressure differential?
a) 5 kPa
b) 10 kPa
c) 15 kPa
d) 20 kPa
Answer: c) 15 kPa
28. What is the maximum allowed concentration of carbon monoxide (CO) in the aircraft cabin?
a) 5 ppm
b) 10 ppm
c) 15 ppm
d) 20 ppm
Answer: d) 20 ppm
29. If the air conditioning system can lower the air temperature by 5°C per minute, how long will it
take to cool the cabin from 30°C to 22°C?
a) 1 minute
b) 1.6 minutes
c) 2 minutes
d) 2.4 minutes
Answer: b) 1.6 minutes
30. What is the typical range of air velocity in the aircraft cabin to maintain passenger comfort?
a) 0.1-0.3 m/s
b) 0.3-0.5 m/s
c) 0.5-0.7 m/s
d) 0.7-0.9 m/s
Answer: a) 0.1-0.3 m/s
31. If the aircraft is climbing at 500 feet per minute, how long will it take for the cabin altitude to
change from 2,000 feet to 8,000 feet?
a) 8 minutes
b) 10 minutes
c) 12 minutes
d) 14 minutes
Answer: c) 12 minutes
32. What percentage of cabin air is typically filtered through HEPA filters?
a) 25%
b) 50%
c) 75%
d) 100%
Answer: d) 100%
33. If the outside air temperature is -55°C and the air is heated to 180°C by compression, what is the
temperature change?
a) 205°C
b) 225°C
c) 235°C
d) 245°C
Answer: c) 235°C
34. What is the typical pressurization rate during aircraft climb?
a) 300-500 ft/min
b) 500-700 ft/min
c) 700-900 ft/min
d) 900-1100 ft/min
Answer: a) 300-500 ft/min
35. If the cabin volume is 400 cubic meters and the air change rate is 16 times per hour, what is the
total air flow rate in cubic meters per hour?
a) 4,800 m³/hr
b) 5,600 m³/hr
c) 6,400 m³/hr
d) 7,200 m³/hr
Answer: c) 6,400 m³/hr
36. What is the typical range of relative humidity in the flight deck?
a) 5-10%
b) 10-15%
c) 15-20%
d) 20-25%
Answer: c) 15-20%
37. If the aircraft is flying at 39,000 feet with a cabin altitude of 6,000 feet, what is the pressure
differential in psi? (Assume 14.7 psi at sea level)
a) 7.2 psi
b) 7.8 psi
c) 8.4 psi
d) 9.0 psi
Answer: c) 8.4 psi
38. How many air changes per hour are typically provided in the flight deck?
a) 10-15
b) 20-25
c) 30-35
d) 40-45
Answer: b) 20-25
39. If the air conditioning system can heat the air at a rate of 3°C per minute, how long will it take to
warm the cabin from 15°C to 24°C?
a) 2 minutes
b) 3 minutes
c) 4 minutes
d) 5 minutes
Answer: b) 3 minutes
40. What is the typical maximum cabin differential pressure for most commercial aircraft?
a) 6.5-7.5 psi
b) 7.5-8.5 psi
c) 8.5-9.5 psi
d) 9.5-10.5 psi
Answer: b) 7.5-8.5 psi
41. If the aircraft has 250 passengers and the air flow rate is 20 CFM per passenger, what is the total
air flow rate in cubic meters per hour? (1 CFM ≈ 1.699 m³/hr)
a) 76,455 m³/hr
b) 84,950 m³/hr
c) 93,445 m³/hr
d) 101,940 m³/hr
Answer: b) 84,950 m³/hr
42. What is the typical pressure altitude inside the cabin when the aircraft is at its maximum
operating altitude?
a) 5,000-6,000 feet
b) 6,000-7,000 feet
c) 7,000-8,000 feet
d) 8,000-9,000 feet
Answer: c) 7,000-8,000 feet
43. If the outside air temperature is -50°C and the air is compressed to 3 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 75°C
c) 100°C
d) 125°C
Answer: c) 100°C
44. What is the typical air flow rate per square meter of cabin floor area?
a) 1-2 L/s/m²
b) 2-3 L/s/m²
c) 3-4 L/s/m²
d) 4-5 L/s/m²
Answer: b) 2-3 L/s/m²
45. If the cabin floor area is 200 m² and the air flow rate is 2.5 L/s/m², what is the total air flow rate
in cubic meters per hour?
a) 1,500 m³/hr
b) 1,800 m³/hr
c) 2,100 m³/hr
d) 2,400 m³/hr
Answer: b) 1,800 m³/hr
46. What is the typical maximum rate of cabin pressure change during normal operations?
a) 200 ft/min
b) 300 ft/min
c) 400 ft/min
d) 500 ft/min
Answer: c) 400 ft/min
47. If the aircraft descends from 35,000 feet to 10,000 feet in 15 minutes, what is the average rate of
descent?
a) 1,000 ft/min
b) 1,500 ft/min
c) 1,667 ft/min
d) 2,000 ft/min
Answer: c) 1,667 ft/min
48. What is the typical temperature of air exiting the air conditioning packs?
a) 0-5°C
b) 5-10°C
c) 10-15°C
d) 15-20°C
Answer: a) 0-5°C
49. If the air conditioning pack delivers 80 kg/min of air at 2°C and mixes with 120 kg/min of
recirculated air at 23°C, what is the resulting temperature?
a) 12°C
b) 14°C
c) 16°C
d) 18°C
Answer: b) 14°C
50. What is the typical range of air pressure in the aircraft cabin during cruise?
a) 70-75 kPa
b) 75-80 kPa
c) 80-85 kPa
d) 85-90 kPa
Answer: b) 75-80 kPa
51. If the cabin volume is 350 cubic meters and the air change rate is 17 times per hour, what is the
total air flow rate in liters per second?
a) 1,458 L/s
b) 1,653 L/s
c) 1,847 L/s
d) 2,042 L/s
Answer: b) 1,653 L/s
How many microns in size are the particles typically filtered out by HEPA filters in aircraft?
a) 0.1 microns
b) 0.3 microns
c) 0.5 microns
d) 1.0 microns
Answer: b) 0.3 microns
17. If the aircraft is descending at 300 feet per minute, how long will it take to change the cabin
altitude from 8,000 feet to 5,000 feet?
a) 5 minutes
b) 10 minutes
c) 15 minutes
d) 20 minutes
Answer: b) 10 minutes
18. What is the typical ozone concentration limit in the aircraft cabin according to FAA regulations?
a) 0.1 ppm
b) 0.25 ppm
c) 0.5 ppm
d) 1.0 ppm
Answer: a) 0.1 ppm
19. If the air conditioning pack delivers 100 kg/min of air at 5°C and mixes with 100 kg/min of
recirculated air at 25°C, what is the resulting temperature?
a) 10°C
b) 15°C
c) 20°C
d) 30°C
Answer: b) 15°C
20. What is the typical CO2 concentration in an aircraft cabin during cruise?
a) 500-1000 ppm
b) 1000-1500 ppm
c) 1500-2000 ppm
d) 2000-2500 ppm
Answer: b) 1000-1500 ppm
21. If the cabin volume is 250 cubic meters and the air change rate is 18 times per hour, what is the
total air flow rate in cubic meters per minute?
a) 45 m³/min
b) 60 m³/min
c) 75 m³/min
d) 90 m³/min
Answer: c) 75 m³/min
22. What is the typical temperature range maintained in the aircraft cabin?
a) 18-22°C
b) 20-24°C
c) 22-26°C
d) 24-28°C
Answer: b) 20-24°C
23. If the outside air temperature is -40°C and the air is compressed to 4 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 100°C
c) 150°C
d) 200°C
Answer: c) 150°C
24. How many pounds of air per minute are typically required for each passenger in an aircraft?
a) 0.5 lbs/min
b) 1.0 lbs/min
c) 1.5 lbs/min
d) 2.0 lbs/min
Answer: b) 1.0 lbs/min
25. If an aircraft has 300 passengers and requires 1.0 lbs/min of air per passenger, what is the total
air requirement in pounds per hour?
a) 9,000 lbs/hr
b) 12,000 lbs/hr
c) 15,000 lbs/hr
d) 18,000 lbs/hr
Answer: d) 18,000 lbs/hr
26. What is the typical efficiency of HEPA filters used in aircraft cabins?
a) 90%
b) 95%
c) 99%
d) 99.97%
Answer: d) 99.97%
27. If the cabin pressure is 75 kPa and the aircraft descends to an altitude where the outside pressure
is 90 kPa, what is the new pressure differential?
a) 5 kPa
b) 10 kPa
c) 15 kPa
d) 20 kPa
Answer: c) 15 kPa
28. What is the maximum allowed concentration of carbon monoxide (CO) in the aircraft cabin?
a) 5 ppm
b) 10 ppm
c) 15 ppm
d) 20 ppm
Answer: d) 20 ppm
29. If the air conditioning system can lower the air temperature by 5°C per minute, how long will it
take to cool the cabin from 30°C to 22°C?
a) 1 minute
b) 1.6 minutes
c) 2 minutes
d) 2.4 minutes
Answer: b) 1.6 minutes
30. What is the typical range of air velocity in the aircraft cabin to maintain passenger comfort?
a) 0.1-0.3 m/s
b) 0.3-0.5 m/s
c) 0.5-0.7 m/s
d) 0.7-0.9 m/s
Answer: a) 0.1-0.3 m/s
31. If the aircraft is climbing at 500 feet per minute, how long will it take for the cabin altitude to
change from 2,000 feet to 8,000 feet?
a) 8 minutes
b) 10 minutes
c) 12 minutes
d) 14 minutes
Answer: c) 12 minutes
32. What percentage of cabin air is typically filtered through HEPA filters?
a) 25%
b) 50%
c) 75%
d) 100%
Answer: d) 100%
33. If the outside air temperature is -55°C and the air is heated to 180°C by compression, what is the
temperature change?
a) 205°C
b) 225°C
c) 235°C
d) 245°C
Answer: c) 235°C
34. What is the typical pressurization rate during aircraft climb?
a) 300-500 ft/min
b) 500-700 ft/min
c) 700-900 ft/min
d) 900-1100 ft/min
Answer: a) 300-500 ft/min
35. If the cabin volume is 400 cubic meters and the air change rate is 16 times per hour, what is the
total air flow rate in cubic meters per hour?
a) 4,800 m³/hr
b) 5,600 m³/hr
c) 6,400 m³/hr
d) 7,200 m³/hr
Answer: c) 6,400 m³/hr
36. What is the typical range of relative humidity in the flight deck?
a) 5-10%
b) 10-15%
c) 15-20%
d) 20-25%
Answer: c) 15-20%
37. If the aircraft is flying at 39,000 feet with a cabin altitude of 6,000 feet, what is the pressure
differential in psi? (Assume 14.7 psi at sea level)
a) 7.2 psi
b) 7.8 psi
c) 8.4 psi
d) 9.0 psi
Answer: c) 8.4 psi
38. How many air changes per hour are typically provided in the flight deck?
a) 10-15
b) 20-25
c) 30-35
d) 40-45
Answer: b) 20-25
39. If the air conditioning system can heat the air at a rate of 3°C per minute, how long will it take to
warm the cabin from 15°C to 24°C?
a) 2 minutes
b) 3 minutes
c) 4 minutes
d) 5 minutes
Answer: b) 3 minutes
40. What is the typical maximum cabin differential pressure for most commercial aircraft?
a) 6.5-7.5 psi
b) 7.5-8.5 psi
c) 8.5-9.5 psi
d) 9.5-10.5 psi
Answer: b) 7.5-8.5 psi
41. If the aircraft has 250 passengers and the air flow rate is 20 CFM per passenger, what is the total
air flow rate in cubic meters per hour? (1 CFM ≈ 1.699 m³/hr)
a) 76,455 m³/hr
b) 84,950 m³/hr
c) 93,445 m³/hr
d) 101,940 m³/hr
Answer: b) 84,950 m³/hr
42. What is the typical pressure altitude inside the cabin when the aircraft is at its maximum
operating altitude?
a) 5,000-6,000 feet
b) 6,000-7,000 feet
c) 7,000-8,000 feet
d) 8,000-9,000 feet
Answer: c) 7,000-8,000 feet
43. If the outside air temperature is -50°C and the air is compressed to 3 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 75°C
c) 100°C
d) 125°C
Answer: c) 100°C
44. What is the typical air flow rate per square meter of cabin floor area?
a) 1-2 L/s/m²
b) 2-3 L/s/m²
c) 3-4 L/s/m²
d) 4-5 L/s/m²
Answer: b) 2-3 L/s/m²
45. If the cabin floor area is 200 m² and the air flow rate is 2.5 L/s/m², what is the total air flow rate
in cubic meters per hour?
a) 1,500 m³/hr
b) 1,800 m³/hr
c) 2,100 m³/hr
d) 2,400 m³/hr
Answer: b) 1,800 m³/hr
46. What is the typical maximum rate of cabin pressure change during normal operations?
a) 200 ft/min
b) 300 ft/min
c) 400 ft/min
d) 500 ft/min
Answer: c) 400 ft/min
47. If the aircraft descends from 35,000 feet to 10,000 feet in 15 minutes, what is the average rate of
descent?
a) 1,000 ft/min
b) 1,500 ft/min
c) 1,667 ft/min
d) 2,000 ft/min
Answer: c) 1,667 ft/min
48. What is the typical temperature of air exiting the air conditioning packs?
a) 0-5°C
b) 5-10°C
c) 10-15°C
d) 15-20°C
Answer: a) 0-5°C
49. If the air conditioning pack delivers 80 kg/min of air at 2°C and mixes with 120 kg/min of
recirculated air at 23°C, what is the resulting temperature?
a) 12°C
b) 14°C
c) 16°C
d) 18°C
Answer: b) 14°C
50. What is the typical range of air pressure in the aircraft cabin during cruise?
a) 70-75 kPa
b) 75-80 kPa
c) 80-85 kPa
d) 85-90 kPa
Answer: b) 75-80 kPa
51. If the cabin volume is 350 cubic meters and the air change rate is 17 times per hour, what is the
total air flow rate in liters per second?
a) 1,458 L/s
b) 1,653 L/s
c) 1,847 L/s
d) 2,042 L/s
Answer: b) 1,653 L/s
How many microns in size are the particles typically filtered out by HEPA filters in aircraft?
a) 0.1 microns
b) 0.3 microns
c) 0.5 microns
d) 1.0 microns
Answer: b) 0.3 microns
17. If the aircraft is descending at 300 feet per minute, how long will it take to change the cabin
altitude from 8,000 feet to 5,000 feet?
a) 5 minutes
b) 10 minutes
c) 15 minutes
d) 20 minutes
Answer: b) 10 minutes
18. What is the typical ozone concentration limit in the aircraft cabin according to FAA regulations?
a) 0.1 ppm
b) 0.25 ppm
c) 0.5 ppm
d) 1.0 ppm
Answer: a) 0.1 ppm
19. If the air conditioning pack delivers 100 kg/min of air at 5°C and mixes with 100 kg/min of
recirculated air at 25°C, what is the resulting temperature?
a) 10°C
b) 15°C
c) 20°C
d) 30°C
Answer: b) 15°C
20. What is the typical CO2 concentration in an aircraft cabin during cruise?
a) 500-1000 ppm
b) 1000-1500 ppm
c) 1500-2000 ppm
d) 2000-2500 ppm
Answer: b) 1000-1500 ppm
21. If the cabin volume is 250 cubic meters and the air change rate is 18 times per hour, what is the
total air flow rate in cubic meters per minute?
a) 45 m³/min
b) 60 m³/min
c) 75 m³/min
d) 90 m³/min
Answer: c) 75 m³/min
22. What is the typical temperature range maintained in the aircraft cabin?
a) 18-22°C
b) 20-24°C
c) 22-26°C
d) 24-28°C
Answer: b) 20-24°C
23. If the outside air temperature is -40°C and the air is compressed to 4 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 100°C
c) 150°C
d) 200°C
Answer: c) 150°C
24. How many pounds of air per minute are typically required for each passenger in an aircraft?
a) 0.5 lbs/min
b) 1.0 lbs/min
c) 1.5 lbs/min
d) 2.0 lbs/min
Answer: b) 1.0 lbs/min
25. If an aircraft has 300 passengers and requires 1.0 lbs/min of air per passenger, what is the total
air requirement in pounds per hour?
a) 9,000 lbs/hr
b) 12,000 lbs/hr
c) 15,000 lbs/hr
d) 18,000 lbs/hr
Answer: d) 18,000 lbs/hr
26. What is the typical efficiency of HEPA filters used in aircraft cabins?
a) 90%
b) 95%
c) 99%
d) 99.97%
Answer: d) 99.97%
27. If the cabin pressure is 75 kPa and the aircraft descends to an altitude where the outside pressure
is 90 kPa, what is the new pressure differential?
a) 5 kPa
b) 10 kPa
c) 15 kPa
d) 20 kPa
Answer: c) 15 kPa
28. What is the maximum allowed concentration of carbon monoxide (CO) in the aircraft cabin?
a) 5 ppm
b) 10 ppm
c) 15 ppm
d) 20 ppm
Answer: d) 20 ppm
29. If the air conditioning system can lower the air temperature by 5°C per minute, how long will it
take to cool the cabin from 30°C to 22°C?
a) 1 minute
b) 1.6 minutes
c) 2 minutes
d) 2.4 minutes
Answer: b) 1.6 minutes
30. What is the typical range of air velocity in the aircraft cabin to maintain passenger comfort?
a) 0.1-0.3 m/s
b) 0.3-0.5 m/s
c) 0.5-0.7 m/s
d) 0.7-0.9 m/s
Answer: a) 0.1-0.3 m/s
31. If the aircraft is climbing at 500 feet per minute, how long will it take for the cabin altitude to
change from 2,000 feet to 8,000 feet?
a) 8 minutes
b) 10 minutes
c) 12 minutes
d) 14 minutes
Answer: c) 12 minutes
32. What percentage of cabin air is typically filtered through HEPA filters?
a) 25%
b) 50%
c) 75%
d) 100%
Answer: d) 100%
33. If the outside air temperature is -55°C and the air is heated to 180°C by compression, what is the
temperature change?
a) 205°C
b) 225°C
c) 235°C
d) 245°C
Answer: c) 235°C
34. What is the typical pressurization rate during aircraft climb?
a) 300-500 ft/min
b) 500-700 ft/min
c) 700-900 ft/min
d) 900-1100 ft/min
Answer: a) 300-500 ft/min
35. If the cabin volume is 400 cubic meters and the air change rate is 16 times per hour, what is the
total air flow rate in cubic meters per hour?
a) 4,800 m³/hr
b) 5,600 m³/hr
c) 6,400 m³/hr
d) 7,200 m³/hr
Answer: c) 6,400 m³/hr
36. What is the typical range of relative humidity in the flight deck?
a) 5-10%
b) 10-15%
c) 15-20%
d) 20-25%
Answer: c) 15-20%
37. If the aircraft is flying at 39,000 feet with a cabin altitude of 6,000 feet, what is the pressure
differential in psi? (Assume 14.7 psi at sea level)
a) 7.2 psi
b) 7.8 psi
c) 8.4 psi
d) 9.0 psi
Answer: c) 8.4 psi
38. How many air changes per hour are typically provided in the flight deck?
a) 10-15
b) 20-25
c) 30-35
d) 40-45
Answer: b) 20-25
39. If the air conditioning system can heat the air at a rate of 3°C per minute, how long will it take to
warm the cabin from 15°C to 24°C?
a) 2 minutes
b) 3 minutes
c) 4 minutes
d) 5 minutes
Answer: b) 3 minutes
40. What is the typical maximum cabin differential pressure for most commercial aircraft?
a) 6.5-7.5 psi
b) 7.5-8.5 psi
c) 8.5-9.5 psi
d) 9.5-10.5 psi
Answer: b) 7.5-8.5 psi
41. If the aircraft has 250 passengers and the air flow rate is 20 CFM per passenger, what is the total
air flow rate in cubic meters per hour? (1 CFM ≈ 1.699 m³/hr)
a) 76,455 m³/hr
b) 84,950 m³/hr
c) 93,445 m³/hr
d) 101,940 m³/hr
Answer: b) 84,950 m³/hr
42. What is the typical pressure altitude inside the cabin when the aircraft is at its maximum
operating altitude?
a) 5,000-6,000 feet
b) 6,000-7,000 feet
c) 7,000-8,000 feet
d) 8,000-9,000 feet
Answer: c) 7,000-8,000 feet
43. If the outside air temperature is -50°C and the air is compressed to 3 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 75°C
c) 100°C
d) 125°C
Answer: c) 100°C
44. What is the typical air flow rate per square meter of cabin floor area?
a) 1-2 L/s/m²
b) 2-3 L/s/m²
c) 3-4 L/s/m²
d) 4-5 L/s/m²
Answer: b) 2-3 L/s/m²
45. If the cabin floor area is 200 m² and the air flow rate is 2.5 L/s/m², what is the total air flow rate
in cubic meters per hour?
a) 1,500 m³/hr
b) 1,800 m³/hr
c) 2,100 m³/hr
d) 2,400 m³/hr
Answer: b) 1,800 m³/hr
46. What is the typical maximum rate of cabin pressure change during normal operations?
a) 200 ft/min
b) 300 ft/min
c) 400 ft/min
d) 500 ft/min
Answer: c) 400 ft/min
47. If the aircraft descends from 35,000 feet to 10,000 feet in 15 minutes, what is the average rate of
descent?
a) 1,000 ft/min
b) 1,500 ft/min
c) 1,667 ft/min
d) 2,000 ft/min
Answer: c) 1,667 ft/min
48. What is the typical temperature of air exiting the air conditioning packs?
a) 0-5°C
b) 5-10°C
c) 10-15°C
d) 15-20°C
Answer: a) 0-5°C
49. If the air conditioning pack delivers 80 kg/min of air at 2°C and mixes with 120 kg/min of
recirculated air at 23°C, what is the resulting temperature?
a) 12°C
b) 14°C
c) 16°C
d) 18°C
Answer: b) 14°C
50. What is the typical range of air pressure in the aircraft cabin during cruise?
a) 70-75 kPa
b) 75-80 kPa
c) 80-85 kPa
d) 85-90 kPa
Answer: b) 75-80 kPa
51. If the cabin volume is 350 cubic meters and the air change rate is 17 times per hour, what is the
total air flow rate in liters per second?
a) 1,458 L/s
b) 1,653 L/s
c) 1,847 L/s
d) 2,042 L/s
Answer: b) 1,653 L/s
How many microns in size are the particles typically filtered out by HEPA filters in aircraft?
a) 0.1 microns
b) 0.3 microns
c) 0.5 microns
d) 1.0 microns
Answer: b) 0.3 microns
17. If the aircraft is descending at 300 feet per minute, how long will it take to change the cabin
altitude from 8,000 feet to 5,000 feet?
a) 5 minutes
b) 10 minutes
c) 15 minutes
d) 20 minutes
Answer: b) 10 minutes
18. What is the typical ozone concentration limit in the aircraft cabin according to FAA regulations?
a) 0.1 ppm
b) 0.25 ppm
c) 0.5 ppm
d) 1.0 ppm
Answer: a) 0.1 ppm
19. If the air conditioning pack delivers 100 kg/min of air at 5°C and mixes with 100 kg/min of
recirculated air at 25°C, what is the resulting temperature?
a) 10°C
b) 15°C
c) 20°C
d) 30°C
Answer: b) 15°C
20. What is the typical CO2 concentration in an aircraft cabin during cruise?
a) 500-1000 ppm
b) 1000-1500 ppm
c) 1500-2000 ppm
d) 2000-2500 ppm
Answer: b) 1000-1500 ppm
21. If the cabin volume is 250 cubic meters and the air change rate is 18 times per hour, what is the
total air flow rate in cubic meters per minute?
a) 45 m³/min
b) 60 m³/min
c) 75 m³/min
d) 90 m³/min
Answer: c) 75 m³/min
22. What is the typical temperature range maintained in the aircraft cabin?
a) 18-22°C
b) 20-24°C
c) 22-26°C
d) 24-28°C
Answer: b) 20-24°C
23. If the outside air temperature is -40°C and the air is compressed to 4 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 100°C
c) 150°C
d) 200°C
Answer: c) 150°C
24. How many pounds of air per minute are typically required for each passenger in an aircraft?
a) 0.5 lbs/min
b) 1.0 lbs/min
c) 1.5 lbs/min
d) 2.0 lbs/min
Answer: b) 1.0 lbs/min
25. If an aircraft has 300 passengers and requires 1.0 lbs/min of air per passenger, what is the total
air requirement in pounds per hour?
a) 9,000 lbs/hr
b) 12,000 lbs/hr
c) 15,000 lbs/hr
d) 18,000 lbs/hr
Answer: d) 18,000 lbs/hr
26. What is the typical efficiency of HEPA filters used in aircraft cabins?
a) 90%
b) 95%
c) 99%
d) 99.97%
Answer: d) 99.97%
27. If the cabin pressure is 75 kPa and the aircraft descends to an altitude where the outside pressure
is 90 kPa, what is the new pressure differential?
a) 5 kPa
b) 10 kPa
c) 15 kPa
d) 20 kPa
Answer: c) 15 kPa
28. What is the maximum allowed concentration of carbon monoxide (CO) in the aircraft cabin?
a) 5 ppm
b) 10 ppm
c) 15 ppm
d) 20 ppm
Answer: d) 20 ppm
29. If the air conditioning system can lower the air temperature by 5°C per minute, how long will it
take to cool the cabin from 30°C to 22°C?
a) 1 minute
b) 1.6 minutes
c) 2 minutes
d) 2.4 minutes
Answer: b) 1.6 minutes
30. What is the typical range of air velocity in the aircraft cabin to maintain passenger comfort?
a) 0.1-0.3 m/s
b) 0.3-0.5 m/s
c) 0.5-0.7 m/s
d) 0.7-0.9 m/s
Answer: a) 0.1-0.3 m/s
31. If the aircraft is climbing at 500 feet per minute, how long will it take for the cabin altitude to
change from 2,000 feet to 8,000 feet?
a) 8 minutes
b) 10 minutes
c) 12 minutes
d) 14 minutes
Answer: c) 12 minutes
32. What percentage of cabin air is typically filtered through HEPA filters?
a) 25%
b) 50%
c) 75%
d) 100%
Answer: d) 100%
33. If the outside air temperature is -55°C and the air is heated to 180°C by compression, what is the
temperature change?
a) 205°C
b) 225°C
c) 235°C
d) 245°C
Answer: c) 235°C
34. What is the typical pressurization rate during aircraft climb?
a) 300-500 ft/min
b) 500-700 ft/min
c) 700-900 ft/min
d) 900-1100 ft/min
Answer: a) 300-500 ft/min
35. If the cabin volume is 400 cubic meters and the air change rate is 16 times per hour, what is the
total air flow rate in cubic meters per hour?
a) 4,800 m³/hr
b) 5,600 m³/hr
c) 6,400 m³/hr
d) 7,200 m³/hr
Answer: c) 6,400 m³/hr
36. What is the typical range of relative humidity in the flight deck?
a) 5-10%
b) 10-15%
c) 15-20%
d) 20-25%
Answer: c) 15-20%
37. If the aircraft is flying at 39,000 feet with a cabin altitude of 6,000 feet, what is the pressure
differential in psi? (Assume 14.7 psi at sea level)
a) 7.2 psi
b) 7.8 psi
c) 8.4 psi
d) 9.0 psi
Answer: c) 8.4 psi
38. How many air changes per hour are typically provided in the flight deck?
a) 10-15
b) 20-25
c) 30-35
d) 40-45
Answer: b) 20-25
39. If the air conditioning system can heat the air at a rate of 3°C per minute, how long will it take to
warm the cabin from 15°C to 24°C?
a) 2 minutes
b) 3 minutes
c) 4 minutes
d) 5 minutes
Answer: b) 3 minutes
40. What is the typical maximum cabin differential pressure for most commercial aircraft?
a) 6.5-7.5 psi
b) 7.5-8.5 psi
c) 8.5-9.5 psi
d) 9.5-10.5 psi
Answer: b) 7.5-8.5 psi
41. If the aircraft has 250 passengers and the air flow rate is 20 CFM per passenger, what is the total
air flow rate in cubic meters per hour? (1 CFM ≈ 1.699 m³/hr)
a) 76,455 m³/hr
b) 84,950 m³/hr
c) 93,445 m³/hr
d) 101,940 m³/hr
Answer: b) 84,950 m³/hr
42. What is the typical pressure altitude inside the cabin when the aircraft is at its maximum
operating altitude?
a) 5,000-6,000 feet
b) 6,000-7,000 feet
c) 7,000-8,000 feet
d) 8,000-9,000 feet
Answer: c) 7,000-8,000 feet
43. If the outside air temperature is -50°C and the air is compressed to 3 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 75°C
c) 100°C
d) 125°C
Answer: c) 100°C
44. What is the typical air flow rate per square meter of cabin floor area?
a) 1-2 L/s/m²
b) 2-3 L/s/m²
c) 3-4 L/s/m²
d) 4-5 L/s/m²
Answer: b) 2-3 L/s/m²
45. If the cabin floor area is 200 m² and the air flow rate is 2.5 L/s/m², what is the total air flow rate
in cubic meters per hour?
a) 1,500 m³/hr
b) 1,800 m³/hr
c) 2,100 m³/hr
d) 2,400 m³/hr
Answer: b) 1,800 m³/hr
46. What is the typical maximum rate of cabin pressure change during normal operations?
a) 200 ft/min
b) 300 ft/min
c) 400 ft/min
d) 500 ft/min
Answer: c) 400 ft/min
47. If the aircraft descends from 35,000 feet to 10,000 feet in 15 minutes, what is the average rate of
descent?
a) 1,000 ft/min
b) 1,500 ft/min
c) 1,667 ft/min
d) 2,000 ft/min
Answer: c) 1,667 ft/min
48. What is the typical temperature of air exiting the air conditioning packs?
a) 0-5°C
b) 5-10°C
c) 10-15°C
d) 15-20°C
Answer: a) 0-5°C
49. If the air conditioning pack delivers 80 kg/min of air at 2°C and mixes with 120 kg/min of
recirculated air at 23°C, what is the resulting temperature?
a) 12°C
b) 14°C
c) 16°C
d) 18°C
Answer: b) 14°C
50. What is the typical range of air pressure in the aircraft cabin during cruise?
a) 70-75 kPa
b) 75-80 kPa
c) 80-85 kPa
d) 85-90 kPa
Answer: b) 75-80 kPa
51. If the cabin volume is 350 cubic meters and the air change rate is 17 times per hour, what is the
total air flow rate in liters per second?
a) 1,458 L/s
b) 1,653 L/s
c) 1,847 L/s
d) 2,042 L/s
Answer: b) 1,653 L/s
How many microns in size are the particles typically filtered out by HEPA filters in aircraft?
a) 0.1 microns
b) 0.3 microns
c) 0.5 microns
d) 1.0 microns
Answer: b) 0.3 microns
17. If the aircraft is descending at 300 feet per minute, how long will it take to change the cabin
altitude from 8,000 feet to 5,000 feet?
a) 5 minutes
b) 10 minutes
c) 15 minutes
d) 20 minutes
Answer: b) 10 minutes
18. What is the typical ozone concentration limit in the aircraft cabin according to FAA regulations?
a) 0.1 ppm
b) 0.25 ppm
c) 0.5 ppm
d) 1.0 ppm
Answer: a) 0.1 ppm
19. If the air conditioning pack delivers 100 kg/min of air at 5°C and mixes with 100 kg/min of
recirculated air at 25°C, what is the resulting temperature?
a) 10°C
b) 15°C
c) 20°C
d) 30°C
Answer: b) 15°C
20. What is the typical CO2 concentration in an aircraft cabin during cruise?
a) 500-1000 ppm
b) 1000-1500 ppm
c) 1500-2000 ppm
d) 2000-2500 ppm
Answer: b) 1000-1500 ppm
21. If the cabin volume is 250 cubic meters and the air change rate is 18 times per hour, what is the
total air flow rate in cubic meters per minute?
a) 45 m³/min
b) 60 m³/min
c) 75 m³/min
d) 90 m³/min
Answer: c) 75 m³/min
22. What is the typical temperature range maintained in the aircraft cabin?
a) 18-22°C
b) 20-24°C
c) 22-26°C
d) 24-28°C
Answer: b) 20-24°C
23. If the outside air temperature is -40°C and the air is compressed to 4 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 100°C
c) 150°C
d) 200°C
Answer: c) 150°C
24. How many pounds of air per minute are typically required for each passenger in an aircraft?
a) 0.5 lbs/min
b) 1.0 lbs/min
c) 1.5 lbs/min
d) 2.0 lbs/min
Answer: b) 1.0 lbs/min
25. If an aircraft has 300 passengers and requires 1.0 lbs/min of air per passenger, what is the total
air requirement in pounds per hour?
a) 9,000 lbs/hr
b) 12,000 lbs/hr
c) 15,000 lbs/hr
d) 18,000 lbs/hr
Answer: d) 18,000 lbs/hr
26. What is the typical efficiency of HEPA filters used in aircraft cabins?
a) 90%
b) 95%
c) 99%
d) 99.97%
Answer: d) 99.97%
27. If the cabin pressure is 75 kPa and the aircraft descends to an altitude where the outside pressure
is 90 kPa, what is the new pressure differential?
a) 5 kPa
b) 10 kPa
c) 15 kPa
d) 20 kPa
Answer: c) 15 kPa
28. What is the maximum allowed concentration of carbon monoxide (CO) in the aircraft cabin?
a) 5 ppm
b) 10 ppm
c) 15 ppm
d) 20 ppm
Answer: d) 20 ppm
29. If the air conditioning system can lower the air temperature by 5°C per minute, how long will it
take to cool the cabin from 30°C to 22°C?
a) 1 minute
b) 1.6 minutes
c) 2 minutes
d) 2.4 minutes
Answer: b) 1.6 minutes
30. What is the typical range of air velocity in the aircraft cabin to maintain passenger comfort?
a) 0.1-0.3 m/s
b) 0.3-0.5 m/s
c) 0.5-0.7 m/s
d) 0.7-0.9 m/s
Answer: a) 0.1-0.3 m/s
31. If the aircraft is climbing at 500 feet per minute, how long will it take for the cabin altitude to
change from 2,000 feet to 8,000 feet?
a) 8 minutes
b) 10 minutes
c) 12 minutes
d) 14 minutes
Answer: c) 12 minutes
32. What percentage of cabin air is typically filtered through HEPA filters?
a) 25%
b) 50%
c) 75%
d) 100%
Answer: d) 100%
33. If the outside air temperature is -55°C and the air is heated to 180°C by compression, what is the
temperature change?
a) 205°C
b) 225°C
c) 235°C
d) 245°C
Answer: c) 235°C
34. What is the typical pressurization rate during aircraft climb?
a) 300-500 ft/min
b) 500-700 ft/min
c) 700-900 ft/min
d) 900-1100 ft/min
Answer: a) 300-500 ft/min
35. If the cabin volume is 400 cubic meters and the air change rate is 16 times per hour, what is the
total air flow rate in cubic meters per hour?
a) 4,800 m³/hr
b) 5,600 m³/hr
c) 6,400 m³/hr
d) 7,200 m³/hr
Answer: c) 6,400 m³/hr
36. What is the typical range of relative humidity in the flight deck?
a) 5-10%
b) 10-15%
c) 15-20%
d) 20-25%
Answer: c) 15-20%
37. If the aircraft is flying at 39,000 feet with a cabin altitude of 6,000 feet, what is the pressure
differential in psi? (Assume 14.7 psi at sea level)
a) 7.2 psi
b) 7.8 psi
c) 8.4 psi
d) 9.0 psi
Answer: c) 8.4 psi
38. How many air changes per hour are typically provided in the flight deck?
a) 10-15
b) 20-25
c) 30-35
d) 40-45
Answer: b) 20-25
39. If the air conditioning system can heat the air at a rate of 3°C per minute, how long will it take to
warm the cabin from 15°C to 24°C?
a) 2 minutes
b) 3 minutes
c) 4 minutes
d) 5 minutes
Answer: b) 3 minutes
40. What is the typical maximum cabin differential pressure for most commercial aircraft?
a) 6.5-7.5 psi
b) 7.5-8.5 psi
c) 8.5-9.5 psi
d) 9.5-10.5 psi
Answer: b) 7.5-8.5 psi
41. If the aircraft has 250 passengers and the air flow rate is 20 CFM per passenger, what is the total
air flow rate in cubic meters per hour? (1 CFM ≈ 1.699 m³/hr)
a) 76,455 m³/hr
b) 84,950 m³/hr
c) 93,445 m³/hr
d) 101,940 m³/hr
Answer: b) 84,950 m³/hr
42. What is the typical pressure altitude inside the cabin when the aircraft is at its maximum
operating altitude?
a) 5,000-6,000 feet
b) 6,000-7,000 feet
c) 7,000-8,000 feet
d) 8,000-9,000 feet
Answer: c) 7,000-8,000 feet
43. If the outside air temperature is -50°C and the air is compressed to 3 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 75°C
c) 100°C
d) 125°C
Answer: c) 100°C
44. What is the typical air flow rate per square meter of cabin floor area?
a) 1-2 L/s/m²
b) 2-3 L/s/m²
c) 3-4 L/s/m²
d) 4-5 L/s/m²
Answer: b) 2-3 L/s/m²
45. If the cabin floor area is 200 m² and the air flow rate is 2.5 L/s/m², what is the total air flow rate
in cubic meters per hour?
a) 1,500 m³/hr
b) 1,800 m³/hr
c) 2,100 m³/hr
d) 2,400 m³/hr
Answer: b) 1,800 m³/hr
46. What is the typical maximum rate of cabin pressure change during normal operations?
a) 200 ft/min
b) 300 ft/min
c) 400 ft/min
d) 500 ft/min
Answer: c) 400 ft/min
47. If the aircraft descends from 35,000 feet to 10,000 feet in 15 minutes, what is the average rate of
descent?
a) 1,000 ft/min
b) 1,500 ft/min
c) 1,667 ft/min
d) 2,000 ft/min
Answer: c) 1,667 ft/min
48. What is the typical temperature of air exiting the air conditioning packs?
a) 0-5°C
b) 5-10°C
c) 10-15°C
d) 15-20°C
Answer: a) 0-5°C
49. If the air conditioning pack delivers 80 kg/min of air at 2°C and mixes with 120 kg/min of
recirculated air at 23°C, what is the resulting temperature?
a) 12°C
b) 14°C
c) 16°C
d) 18°C
Answer: b) 14°C
50. What is the typical range of air pressure in the aircraft cabin during cruise?
a) 70-75 kPa
b) 75-80 kPa
c) 80-85 kPa
d) 85-90 kPa
Answer: b) 75-80 kPa
51. If the cabin volume is 350 cubic meters and the air change rate is 17 times per hour, what is the
total air flow rate in liters per second?
a) 1,458 L/s
b) 1,653 L/s
c) 1,847 L/s
d) 2,042 L/s
Answer: b) 1,653 L/s
How many microns in size are the particles typically filtered out by HEPA filters in aircraft?
a) 0.1 microns
b) 0.3 microns
c) 0.5 microns
d) 1.0 microns
Answer: b) 0.3 microns
17. If the aircraft is descending at 300 feet per minute, how long will it take to change the cabin
altitude from 8,000 feet to 5,000 feet?
a) 5 minutes
b) 10 minutes
c) 15 minutes
d) 20 minutes
Answer: b) 10 minutes
18. What is the typical ozone concentration limit in the aircraft cabin according to FAA regulations?
a) 0.1 ppm
b) 0.25 ppm
c) 0.5 ppm
d) 1.0 ppm
Answer: a) 0.1 ppm
19. If the air conditioning pack delivers 100 kg/min of air at 5°C and mixes with 100 kg/min of
recirculated air at 25°C, what is the resulting temperature?
a) 10°C
b) 15°C
c) 20°C
d) 30°C
Answer: b) 15°C
20. What is the typical CO2 concentration in an aircraft cabin during cruise?
a) 500-1000 ppm
b) 1000-1500 ppm
c) 1500-2000 ppm
d) 2000-2500 ppm
Answer: b) 1000-1500 ppm
21. If the cabin volume is 250 cubic meters and the air change rate is 18 times per hour, what is the
total air flow rate in cubic meters per minute?
a) 45 m³/min
b) 60 m³/min
c) 75 m³/min
d) 90 m³/min
Answer: c) 75 m³/min
22. What is the typical temperature range maintained in the aircraft cabin?
a) 18-22°C
b) 20-24°C
c) 22-26°C
d) 24-28°C
Answer: b) 20-24°C
23. If the outside air temperature is -40°C and the air is compressed to 4 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 100°C
c) 150°C
d) 200°C
Answer: c) 150°C
24. How many pounds of air per minute are typically required for each passenger in an aircraft?
a) 0.5 lbs/min
b) 1.0 lbs/min
c) 1.5 lbs/min
d) 2.0 lbs/min
Answer: b) 1.0 lbs/min
25. If an aircraft has 300 passengers and requires 1.0 lbs/min of air per passenger, what is the total
air requirement in pounds per hour?
a) 9,000 lbs/hr
b) 12,000 lbs/hr
c) 15,000 lbs/hr
d) 18,000 lbs/hr
Answer: d) 18,000 lbs/hr
26. What is the typical efficiency of HEPA filters used in aircraft cabins?
a) 90%
b) 95%
c) 99%
d) 99.97%
Answer: d) 99.97%
27. If the cabin pressure is 75 kPa and the aircraft descends to an altitude where the outside pressure
is 90 kPa, what is the new pressure differential?
a) 5 kPa
b) 10 kPa
c) 15 kPa
d) 20 kPa
Answer: c) 15 kPa
28. What is the maximum allowed concentration of carbon monoxide (CO) in the aircraft cabin?
a) 5 ppm
b) 10 ppm
c) 15 ppm
d) 20 ppm
Answer: d) 20 ppm
29. If the air conditioning system can lower the air temperature by 5°C per minute, how long will it
take to cool the cabin from 30°C to 22°C?
a) 1 minute
b) 1.6 minutes
c) 2 minutes
d) 2.4 minutes
Answer: b) 1.6 minutes
30. What is the typical range of air velocity in the aircraft cabin to maintain passenger comfort?
a) 0.1-0.3 m/s
b) 0.3-0.5 m/s
c) 0.5-0.7 m/s
d) 0.7-0.9 m/s
Answer: a) 0.1-0.3 m/s
31. If the aircraft is climbing at 500 feet per minute, how long will it take for the cabin altitude to
change from 2,000 feet to 8,000 feet?
a) 8 minutes
b) 10 minutes
c) 12 minutes
d) 14 minutes
Answer: c) 12 minutes
32. What percentage of cabin air is typically filtered through HEPA filters?
a) 25%
b) 50%
c) 75%
d) 100%
Answer: d) 100%
33. If the outside air temperature is -55°C and the air is heated to 180°C by compression, what is the
temperature change?
a) 205°C
b) 225°C
c) 235°C
d) 245°C
Answer: c) 235°C
34. What is the typical pressurization rate during aircraft climb?
a) 300-500 ft/min
b) 500-700 ft/min
c) 700-900 ft/min
d) 900-1100 ft/min
Answer: a) 300-500 ft/min
35. If the cabin volume is 400 cubic meters and the air change rate is 16 times per hour, what is the
total air flow rate in cubic meters per hour?
a) 4,800 m³/hr
b) 5,600 m³/hr
c) 6,400 m³/hr
d) 7,200 m³/hr
Answer: c) 6,400 m³/hr
36. What is the typical range of relative humidity in the flight deck?
a) 5-10%
b) 10-15%
c) 15-20%
d) 20-25%
Answer: c) 15-20%
37. If the aircraft is flying at 39,000 feet with a cabin altitude of 6,000 feet, what is the pressure
differential in psi? (Assume 14.7 psi at sea level)
a) 7.2 psi
b) 7.8 psi
c) 8.4 psi
d) 9.0 psi
Answer: c) 8.4 psi
38. How many air changes per hour are typically provided in the flight deck?
a) 10-15
b) 20-25
c) 30-35
d) 40-45
Answer: b) 20-25
39. If the air conditioning system can heat the air at a rate of 3°C per minute, how long will it take to
warm the cabin from 15°C to 24°C?
a) 2 minutes
b) 3 minutes
c) 4 minutes
d) 5 minutes
Answer: b) 3 minutes
40. What is the typical maximum cabin differential pressure for most commercial aircraft?
a) 6.5-7.5 psi
b) 7.5-8.5 psi
c) 8.5-9.5 psi
d) 9.5-10.5 psi
Answer: b) 7.5-8.5 psi
41. If the aircraft has 250 passengers and the air flow rate is 20 CFM per passenger, what is the total
air flow rate in cubic meters per hour? (1 CFM ≈ 1.699 m³/hr)
a) 76,455 m³/hr
b) 84,950 m³/hr
c) 93,445 m³/hr
d) 101,940 m³/hr
Answer: b) 84,950 m³/hr
42. What is the typical pressure altitude inside the cabin when the aircraft is at its maximum
operating altitude?
a) 5,000-6,000 feet
b) 6,000-7,000 feet
c) 7,000-8,000 feet
d) 8,000-9,000 feet
Answer: c) 7,000-8,000 feet
43. If the outside air temperature is -50°C and the air is compressed to 3 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 75°C
c) 100°C
d) 125°C
Answer: c) 100°C
44. What is the typical air flow rate per square meter of cabin floor area?
a) 1-2 L/s/m²
b) 2-3 L/s/m²
c) 3-4 L/s/m²
d) 4-5 L/s/m²
Answer: b) 2-3 L/s/m²
45. If the cabin floor area is 200 m² and the air flow rate is 2.5 L/s/m², what is the total air flow rate
in cubic meters per hour?
a) 1,500 m³/hr
b) 1,800 m³/hr
c) 2,100 m³/hr
d) 2,400 m³/hr
Answer: b) 1,800 m³/hr
46. What is the typical maximum rate of cabin pressure change during normal operations?
a) 200 ft/min
b) 300 ft/min
c) 400 ft/min
d) 500 ft/min
Answer: c) 400 ft/min
47. If the aircraft descends from 35,000 feet to 10,000 feet in 15 minutes, what is the average rate of
descent?
a) 1,000 ft/min
b) 1,500 ft/min
c) 1,667 ft/min
d) 2,000 ft/min
Answer: c) 1,667 ft/min
48. What is the typical temperature of air exiting the air conditioning packs?
a) 0-5°C
b) 5-10°C
c) 10-15°C
d) 15-20°C
Answer: a) 0-5°C
49. If the air conditioning pack delivers 80 kg/min of air at 2°C and mixes with 120 kg/min of
recirculated air at 23°C, what is the resulting temperature?
a) 12°C
b) 14°C
c) 16°C
d) 18°C
Answer: b) 14°C
50. What is the typical range of air pressure in the aircraft cabin during cruise?
a) 70-75 kPa
b) 75-80 kPa
c) 80-85 kPa
d) 85-90 kPa
Answer: b) 75-80 kPa
51. If the cabin volume is 350 cubic meters and the air change rate is 17 times per hour, what is the
total air flow rate in liters per second?
a) 1,458 L/s
b) 1,653 L/s
c) 1,847 L/s
d) 2,042 L/s
Answer: b) 1,653 L/s
How many microns in size are the particles typically filtered out by HEPA filters in aircraft?
a) 0.1 microns
b) 0.3 microns
c) 0.5 microns
d) 1.0 microns
Answer: b) 0.3 microns
17. If the aircraft is descending at 300 feet per minute, how long will it take to change the cabin
altitude from 8,000 feet to 5,000 feet?
a) 5 minutes
b) 10 minutes
c) 15 minutes
d) 20 minutes
Answer: b) 10 minutes
18. What is the typical ozone concentration limit in the aircraft cabin according to FAA regulations?
a) 0.1 ppm
b) 0.25 ppm
c) 0.5 ppm
d) 1.0 ppm
Answer: a) 0.1 ppm
19. If the air conditioning pack delivers 100 kg/min of air at 5°C and mixes with 100 kg/min of
recirculated air at 25°C, what is the resulting temperature?
a) 10°C
b) 15°C
c) 20°C
d) 30°C
Answer: b) 15°C
20. What is the typical CO2 concentration in an aircraft cabin during cruise?
a) 500-1000 ppm
b) 1000-1500 ppm
c) 1500-2000 ppm
d) 2000-2500 ppm
Answer: b) 1000-1500 ppm
21. If the cabin volume is 250 cubic meters and the air change rate is 18 times per hour, what is the
total air flow rate in cubic meters per minute?
a) 45 m³/min
b) 60 m³/min
c) 75 m³/min
d) 90 m³/min
Answer: c) 75 m³/min
22. What is the typical temperature range maintained in the aircraft cabin?
a) 18-22°C
b) 20-24°C
c) 22-26°C
d) 24-28°C
Answer: b) 20-24°C
23. If the outside air temperature is -40°C and the air is compressed to 4 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 100°C
c) 150°C
d) 200°C
Answer: c) 150°C
24. How many pounds of air per minute are typically required for each passenger in an aircraft?
a) 0.5 lbs/min
b) 1.0 lbs/min
c) 1.5 lbs/min
d) 2.0 lbs/min
Answer: b) 1.0 lbs/min
25. If an aircraft has 300 passengers and requires 1.0 lbs/min of air per passenger, what is the total
air requirement in pounds per hour?
a) 9,000 lbs/hr
b) 12,000 lbs/hr
c) 15,000 lbs/hr
d) 18,000 lbs/hr
Answer: d) 18,000 lbs/hr
26. What is the typical efficiency of HEPA filters used in aircraft cabins?
a) 90%
b) 95%
c) 99%
d) 99.97%
Answer: d) 99.97%
27. If the cabin pressure is 75 kPa and the aircraft descends to an altitude where the outside pressure
is 90 kPa, what is the new pressure differential?
a) 5 kPa
b) 10 kPa
c) 15 kPa
d) 20 kPa
Answer: c) 15 kPa
28. What is the maximum allowed concentration of carbon monoxide (CO) in the aircraft cabin?
a) 5 ppm
b) 10 ppm
c) 15 ppm
d) 20 ppm
Answer: d) 20 ppm
29. If the air conditioning system can lower the air temperature by 5°C per minute, how long will it
take to cool the cabin from 30°C to 22°C?
a) 1 minute
b) 1.6 minutes
c) 2 minutes
d) 2.4 minutes
Answer: b) 1.6 minutes
30. What is the typical range of air velocity in the aircraft cabin to maintain passenger comfort?
a) 0.1-0.3 m/s
b) 0.3-0.5 m/s
c) 0.5-0.7 m/s
d) 0.7-0.9 m/s
Answer: a) 0.1-0.3 m/s
31. If the aircraft is climbing at 500 feet per minute, how long will it take for the cabin altitude to
change from 2,000 feet to 8,000 feet?
a) 8 minutes
b) 10 minutes
c) 12 minutes
d) 14 minutes
Answer: c) 12 minutes
32. What percentage of cabin air is typically filtered through HEPA filters?
a) 25%
b) 50%
c) 75%
d) 100%
Answer: d) 100%
33. If the outside air temperature is -55°C and the air is heated to 180°C by compression, what is the
temperature change?
a) 205°C
b) 225°C
c) 235°C
d) 245°C
Answer: c) 235°C
34. What is the typical pressurization rate during aircraft climb?
a) 300-500 ft/min
b) 500-700 ft/min
c) 700-900 ft/min
d) 900-1100 ft/min
Answer: a) 300-500 ft/min
35. If the cabin volume is 400 cubic meters and the air change rate is 16 times per hour, what is the
total air flow rate in cubic meters per hour?
a) 4,800 m³/hr
b) 5,600 m³/hr
c) 6,400 m³/hr
d) 7,200 m³/hr
Answer: c) 6,400 m³/hr
36. What is the typical range of relative humidity in the flight deck?
a) 5-10%
b) 10-15%
c) 15-20%
d) 20-25%
Answer: c) 15-20%
37. If the aircraft is flying at 39,000 feet with a cabin altitude of 6,000 feet, what is the pressure
differential in psi? (Assume 14.7 psi at sea level)
a) 7.2 psi
b) 7.8 psi
c) 8.4 psi
d) 9.0 psi
Answer: c) 8.4 psi
38. How many air changes per hour are typically provided in the flight deck?
a) 10-15
b) 20-25
c) 30-35
d) 40-45
Answer: b) 20-25
39. If the air conditioning system can heat the air at a rate of 3°C per minute, how long will it take to
warm the cabin from 15°C to 24°C?
a) 2 minutes
b) 3 minutes
c) 4 minutes
d) 5 minutes
Answer: b) 3 minutes
40. What is the typical maximum cabin differential pressure for most commercial aircraft?
a) 6.5-7.5 psi
b) 7.5-8.5 psi
c) 8.5-9.5 psi
d) 9.5-10.5 psi
Answer: b) 7.5-8.5 psi
41. If the aircraft has 250 passengers and the air flow rate is 20 CFM per passenger, what is the total
air flow rate in cubic meters per hour? (1 CFM ≈ 1.699 m³/hr)
a) 76,455 m³/hr
b) 84,950 m³/hr
c) 93,445 m³/hr
d) 101,940 m³/hr
Answer: b) 84,950 m³/hr
42. What is the typical pressure altitude inside the cabin when the aircraft is at its maximum
operating altitude?
a) 5,000-6,000 feet
b) 6,000-7,000 feet
c) 7,000-8,000 feet
d) 8,000-9,000 feet
Answer: c) 7,000-8,000 feet
43. If the outside air temperature is -50°C and the air is compressed to 3 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 75°C
c) 100°C
d) 125°C
Answer: c) 100°C
44. What is the typical air flow rate per square meter of cabin floor area?
a) 1-2 L/s/m²
b) 2-3 L/s/m²
c) 3-4 L/s/m²
d) 4-5 L/s/m²
Answer: b) 2-3 L/s/m²
45. If the cabin floor area is 200 m² and the air flow rate is 2.5 L/s/m², what is the total air flow rate
in cubic meters per hour?
a) 1,500 m³/hr
b) 1,800 m³/hr
c) 2,100 m³/hr
d) 2,400 m³/hr
Answer: b) 1,800 m³/hr
46. What is the typical maximum rate of cabin pressure change during normal operations?
a) 200 ft/min
b) 300 ft/min
c) 400 ft/min
d) 500 ft/min
Answer: c) 400 ft/min
47. If the aircraft descends from 35,000 feet to 10,000 feet in 15 minutes, what is the average rate of
descent?
a) 1,000 ft/min
b) 1,500 ft/min
c) 1,667 ft/min
d) 2,000 ft/min
Answer: c) 1,667 ft/min
48. What is the typical temperature of air exiting the air conditioning packs?
a) 0-5°C
b) 5-10°C
c) 10-15°C
d) 15-20°C
Answer: a) 0-5°C
49. If the air conditioning pack delivers 80 kg/min of air at 2°C and mixes with 120 kg/min of
recirculated air at 23°C, what is the resulting temperature?
a) 12°C
b) 14°C
c) 16°C
d) 18°C
Answer: b) 14°C
50. What is the typical range of air pressure in the aircraft cabin during cruise?
a) 70-75 kPa
b) 75-80 kPa
c) 80-85 kPa
d) 85-90 kPa
Answer: b) 75-80 kPa
51. If the cabin volume is 350 cubic meters and the air change rate is 17 times per hour, what is the
total air flow rate in liters per second?
a) 1,458 L/s
b) 1,653 L/s
c) 1,847 L/s
d) 2,042 L/s
Answer: b) 1,653 L/s
How many microns in size are the particles typically filtered out by HEPA filters in aircraft?
a) 0.1 microns
b) 0.3 microns
c) 0.5 microns
d) 1.0 microns
Answer: b) 0.3 microns
17. If the aircraft is descending at 300 feet per minute, how long will it take to change the cabin
altitude from 8,000 feet to 5,000 feet?
a) 5 minutes
b) 10 minutes
c) 15 minutes
d) 20 minutes
Answer: b) 10 minutes
18. What is the typical ozone concentration limit in the aircraft cabin according to FAA regulations?
a) 0.1 ppm
b) 0.25 ppm
c) 0.5 ppm
d) 1.0 ppm
Answer: a) 0.1 ppm
19. If the air conditioning pack delivers 100 kg/min of air at 5°C and mixes with 100 kg/min of
recirculated air at 25°C, what is the resulting temperature?
a) 10°C
b) 15°C
c) 20°C
d) 30°C
Answer: b) 15°C
20. What is the typical CO2 concentration in an aircraft cabin during cruise?
a) 500-1000 ppm
b) 1000-1500 ppm
c) 1500-2000 ppm
d) 2000-2500 ppm
Answer: b) 1000-1500 ppm
21. If the cabin volume is 250 cubic meters and the air change rate is 18 times per hour, what is the
total air flow rate in cubic meters per minute?
a) 45 m³/min
b) 60 m³/min
c) 75 m³/min
d) 90 m³/min
Answer: c) 75 m³/min
22. What is the typical temperature range maintained in the aircraft cabin?
a) 18-22°C
b) 20-24°C
c) 22-26°C
d) 24-28°C
Answer: b) 20-24°C
23. If the outside air temperature is -40°C and the air is compressed to 4 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 100°C
c) 150°C
d) 200°C
Answer: c) 150°C
24. How many pounds of air per minute are typically required for each passenger in an aircraft?
a) 0.5 lbs/min
b) 1.0 lbs/min
c) 1.5 lbs/min
d) 2.0 lbs/min
Answer: b) 1.0 lbs/min
25. If an aircraft has 300 passengers and requires 1.0 lbs/min of air per passenger, what is the total
air requirement in pounds per hour?
a) 9,000 lbs/hr
b) 12,000 lbs/hr
c) 15,000 lbs/hr
d) 18,000 lbs/hr
Answer: d) 18,000 lbs/hr
26. What is the typical efficiency of HEPA filters used in aircraft cabins?
a) 90%
b) 95%
c) 99%
d) 99.97%
Answer: d) 99.97%
27. If the cabin pressure is 75 kPa and the aircraft descends to an altitude where the outside pressure
is 90 kPa, what is the new pressure differential?
a) 5 kPa
b) 10 kPa
c) 15 kPa
d) 20 kPa
Answer: c) 15 kPa
28. What is the maximum allowed concentration of carbon monoxide (CO) in the aircraft cabin?
a) 5 ppm
b) 10 ppm
c) 15 ppm
d) 20 ppm
Answer: d) 20 ppm
29. If the air conditioning system can lower the air temperature by 5°C per minute, how long will it
take to cool the cabin from 30°C to 22°C?
a) 1 minute
b) 1.6 minutes
c) 2 minutes
d) 2.4 minutes
Answer: b) 1.6 minutes
30. What is the typical range of air velocity in the aircraft cabin to maintain passenger comfort?
a) 0.1-0.3 m/s
b) 0.3-0.5 m/s
c) 0.5-0.7 m/s
d) 0.7-0.9 m/s
Answer: a) 0.1-0.3 m/s
31. If the aircraft is climbing at 500 feet per minute, how long will it take for the cabin altitude to
change from 2,000 feet to 8,000 feet?
a) 8 minutes
b) 10 minutes
c) 12 minutes
d) 14 minutes
Answer: c) 12 minutes
32. What percentage of cabin air is typically filtered through HEPA filters?
a) 25%
b) 50%
c) 75%
d) 100%
Answer: d) 100%
33. If the outside air temperature is -55°C and the air is heated to 180°C by compression, what is the
temperature change?
a) 205°C
b) 225°C
c) 235°C
d) 245°C
Answer: c) 235°C
34. What is the typical pressurization rate during aircraft climb?
a) 300-500 ft/min
b) 500-700 ft/min
c) 700-900 ft/min
d) 900-1100 ft/min
Answer: a) 300-500 ft/min
35. If the cabin volume is 400 cubic meters and the air change rate is 16 times per hour, what is the
total air flow rate in cubic meters per hour?
a) 4,800 m³/hr
b) 5,600 m³/hr
c) 6,400 m³/hr
d) 7,200 m³/hr
Answer: c) 6,400 m³/hr
36. What is the typical range of relative humidity in the flight deck?
a) 5-10%
b) 10-15%
c) 15-20%
d) 20-25%
Answer: c) 15-20%
37. If the aircraft is flying at 39,000 feet with a cabin altitude of 6,000 feet, what is the pressure
differential in psi? (Assume 14.7 psi at sea level)
a) 7.2 psi
b) 7.8 psi
c) 8.4 psi
d) 9.0 psi
Answer: c) 8.4 psi
38. How many air changes per hour are typically provided in the flight deck?
a) 10-15
b) 20-25
c) 30-35
d) 40-45
Answer: b) 20-25
39. If the air conditioning system can heat the air at a rate of 3°C per minute, how long will it take to
warm the cabin from 15°C to 24°C?
a) 2 minutes
b) 3 minutes
c) 4 minutes
d) 5 minutes
Answer: b) 3 minutes
40. What is the typical maximum cabin differential pressure for most commercial aircraft?
a) 6.5-7.5 psi
b) 7.5-8.5 psi
c) 8.5-9.5 psi
d) 9.5-10.5 psi
Answer: b) 7.5-8.5 psi
41. If the aircraft has 250 passengers and the air flow rate is 20 CFM per passenger, what is the total
air flow rate in cubic meters per hour? (1 CFM ≈ 1.699 m³/hr)
a) 76,455 m³/hr
b) 84,950 m³/hr
c) 93,445 m³/hr
d) 101,940 m³/hr
Answer: b) 84,950 m³/hr
42. What is the typical pressure altitude inside the cabin when the aircraft is at its maximum
operating altitude?
a) 5,000-6,000 feet
b) 6,000-7,000 feet
c) 7,000-8,000 feet
d) 8,000-9,000 feet
Answer: c) 7,000-8,000 feet
43. If the outside air temperature is -50°C and the air is compressed to 3 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 75°C
c) 100°C
d) 125°C
Answer: c) 100°C
44. What is the typical air flow rate per square meter of cabin floor area?
a) 1-2 L/s/m²
b) 2-3 L/s/m²
c) 3-4 L/s/m²
d) 4-5 L/s/m²
Answer: b) 2-3 L/s/m²
45. If the cabin floor area is 200 m² and the air flow rate is 2.5 L/s/m², what is the total air flow rate
in cubic meters per hour?
a) 1,500 m³/hr
b) 1,800 m³/hr
c) 2,100 m³/hr
d) 2,400 m³/hr
Answer: b) 1,800 m³/hr
46. What is the typical maximum rate of cabin pressure change during normal operations?
a) 200 ft/min
b) 300 ft/min
c) 400 ft/min
d) 500 ft/min
Answer: c) 400 ft/min
47. If the aircraft descends from 35,000 feet to 10,000 feet in 15 minutes, what is the average rate of
descent?
a) 1,000 ft/min
b) 1,500 ft/min
c) 1,667 ft/min
d) 2,000 ft/min
Answer: c) 1,667 ft/min
48. What is the typical temperature of air exiting the air conditioning packs?
a) 0-5°C
b) 5-10°C
c) 10-15°C
d) 15-20°C
Answer: a) 0-5°C
49. If the air conditioning pack delivers 80 kg/min of air at 2°C and mixes with 120 kg/min of
recirculated air at 23°C, what is the resulting temperature?
a) 12°C
b) 14°C
c) 16°C
d) 18°C
Answer: b) 14°C
50. What is the typical range of air pressure in the aircraft cabin during cruise?
a) 70-75 kPa
b) 75-80 kPa
c) 80-85 kPa
d) 85-90 kPa
Answer: b) 75-80 kPa
51. If the cabin volume is 350 cubic meters and the air change rate is 17 times per hour, what is the
total air flow rate in liters per second?
a) 1,458 L/s
b) 1,653 L/s
c) 1,847 L/s
d) 2,042 L/s
Answer: b) 1,653 L/s
How many microns in size are the particles typically filtered out by HEPA filters in aircraft?
a) 0.1 microns
b) 0.3 microns
c) 0.5 microns
d) 1.0 microns
Answer: b) 0.3 microns
17. If the aircraft is descending at 300 feet per minute, how long will it take to change the cabin
altitude from 8,000 feet to 5,000 feet?
a) 5 minutes
b) 10 minutes
c) 15 minutes
d) 20 minutes
Answer: b) 10 minutes
18. What is the typical ozone concentration limit in the aircraft cabin according to FAA regulations?
a) 0.1 ppm
b) 0.25 ppm
c) 0.5 ppm
d) 1.0 ppm
Answer: a) 0.1 ppm
19. If the air conditioning pack delivers 100 kg/min of air at 5°C and mixes with 100 kg/min of
recirculated air at 25°C, what is the resulting temperature?
a) 10°C
b) 15°C
c) 20°C
d) 30°C
Answer: b) 15°C
20. What is the typical CO2 concentration in an aircraft cabin during cruise?
a) 500-1000 ppm
b) 1000-1500 ppm
c) 1500-2000 ppm
d) 2000-2500 ppm
Answer: b) 1000-1500 ppm
21. If the cabin volume is 250 cubic meters and the air change rate is 18 times per hour, what is the
total air flow rate in cubic meters per minute?
a) 45 m³/min
b) 60 m³/min
c) 75 m³/min
d) 90 m³/min
Answer: c) 75 m³/min
22. What is the typical temperature range maintained in the aircraft cabin?
a) 18-22°C
b) 20-24°C
c) 22-26°C
d) 24-28°C
Answer: b) 20-24°C
23. If the outside air temperature is -40°C and the air is compressed to 4 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 100°C
c) 150°C
d) 200°C
Answer: c) 150°C
24. How many pounds of air per minute are typically required for each passenger in an aircraft?
a) 0.5 lbs/min
b) 1.0 lbs/min
c) 1.5 lbs/min
d) 2.0 lbs/min
Answer: b) 1.0 lbs/min
25. If an aircraft has 300 passengers and requires 1.0 lbs/min of air per passenger, what is the total
air requirement in pounds per hour?
a) 9,000 lbs/hr
b) 12,000 lbs/hr
c) 15,000 lbs/hr
d) 18,000 lbs/hr
Answer: d) 18,000 lbs/hr
26. What is the typical efficiency of HEPA filters used in aircraft cabins?
a) 90%
b) 95%
c) 99%
d) 99.97%
Answer: d) 99.97%
27. If the cabin pressure is 75 kPa and the aircraft descends to an altitude where the outside pressure
is 90 kPa, what is the new pressure differential?
a) 5 kPa
b) 10 kPa
c) 15 kPa
d) 20 kPa
Answer: c) 15 kPa
28. What is the maximum allowed concentration of carbon monoxide (CO) in the aircraft cabin?
a) 5 ppm
b) 10 ppm
c) 15 ppm
d) 20 ppm
Answer: d) 20 ppm
29. If the air conditioning system can lower the air temperature by 5°C per minute, how long will it
take to cool the cabin from 30°C to 22°C?
a) 1 minute
b) 1.6 minutes
c) 2 minutes
d) 2.4 minutes
Answer: b) 1.6 minutes
30. What is the typical range of air velocity in the aircraft cabin to maintain passenger comfort?
a) 0.1-0.3 m/s
b) 0.3-0.5 m/s
c) 0.5-0.7 m/s
d) 0.7-0.9 m/s
Answer: a) 0.1-0.3 m/s
31. If the aircraft is climbing at 500 feet per minute, how long will it take for the cabin altitude to
change from 2,000 feet to 8,000 feet?
a) 8 minutes
b) 10 minutes
c) 12 minutes
d) 14 minutes
Answer: c) 12 minutes
32. What percentage of cabin air is typically filtered through HEPA filters?
a) 25%
b) 50%
c) 75%
d) 100%
Answer: d) 100%
33. If the outside air temperature is -55°C and the air is heated to 180°C by compression, what is the
temperature change?
a) 205°C
b) 225°C
c) 235°C
d) 245°C
Answer: c) 235°C
34. What is the typical pressurization rate during aircraft climb?
a) 300-500 ft/min
b) 500-700 ft/min
c) 700-900 ft/min
d) 900-1100 ft/min
Answer: a) 300-500 ft/min
35. If the cabin volume is 400 cubic meters and the air change rate is 16 times per hour, what is the
total air flow rate in cubic meters per hour?
a) 4,800 m³/hr
b) 5,600 m³/hr
c) 6,400 m³/hr
d) 7,200 m³/hr
Answer: c) 6,400 m³/hr
36. What is the typical range of relative humidity in the flight deck?
a) 5-10%
b) 10-15%
c) 15-20%
d) 20-25%
Answer: c) 15-20%
37. If the aircraft is flying at 39,000 feet with a cabin altitude of 6,000 feet, what is the pressure
differential in psi? (Assume 14.7 psi at sea level)
a) 7.2 psi
b) 7.8 psi
c) 8.4 psi
d) 9.0 psi
Answer: c) 8.4 psi
38. How many air changes per hour are typically provided in the flight deck?
a) 10-15
b) 20-25
c) 30-35
d) 40-45
Answer: b) 20-25
39. If the air conditioning system can heat the air at a rate of 3°C per minute, how long will it take to
warm the cabin from 15°C to 24°C?
a) 2 minutes
b) 3 minutes
c) 4 minutes
d) 5 minutes
Answer: b) 3 minutes
40. What is the typical maximum cabin differential pressure for most commercial aircraft?
a) 6.5-7.5 psi
b) 7.5-8.5 psi
c) 8.5-9.5 psi
d) 9.5-10.5 psi
Answer: b) 7.5-8.5 psi
41. If the aircraft has 250 passengers and the air flow rate is 20 CFM per passenger, what is the total
air flow rate in cubic meters per hour? (1 CFM ≈ 1.699 m³/hr)
a) 76,455 m³/hr
b) 84,950 m³/hr
c) 93,445 m³/hr
d) 101,940 m³/hr
Answer: b) 84,950 m³/hr
42. What is the typical pressure altitude inside the cabin when the aircraft is at its maximum
operating altitude?
a) 5,000-6,000 feet
b) 6,000-7,000 feet
c) 7,000-8,000 feet
d) 8,000-9,000 feet
Answer: c) 7,000-8,000 feet
43. If the outside air temperature is -50°C and the air is compressed to 3 times its original pressure,
what is the approximate temperature after compression (assuming adiabatic compression)?
a) 50°C
b) 75°C
c) 100°C
d) 125°C
Answer: c) 100°C
44. What is the typical air flow rate per square meter of cabin floor area?
a) 1-2 L/s/m²
b) 2-3 L/s/m²
c) 3-4 L/s/m²
d) 4-5 L/s/m²
Answer: b) 2-3 L/s/m²
45. If the cabin floor area is 200 m² and the air flow rate is 2.5 L/s/m², what is the total air flow rate
in cubic meters per hour?
a) 1,500 m³/hr
b) 1,800 m³/hr
c) 2,100 m³/hr
d) 2,400 m³/hr
Answer: b) 1,800 m³/hr
46. What is the typical maximum rate of cabin pressure change during normal operations?
a) 200 ft/min
b) 300 ft/min
c) 400 ft/min
d) 500 ft/min
Answer: c) 400 ft/min
47. If the aircraft descends from 35,000 feet to 10,000 feet in 15 minutes, what is the average rate of
descent?
a) 1,000 ft/min
b) 1,500 ft/min
c) 1,667 ft/min
d) 2,000 ft/min
Answer: c) 1,667 ft/min
48. What is the typical temperature of air exiting the air conditioning packs?
a) 0-5°C
b) 5-10°C
c) 10-15°C
d) 15-20°C
Answer: a) 0-5°C
49. If the air conditioning pack delivers 80 kg/min of air at 2°C and mixes with 120 kg/min of
recirculated air at 23°C, what is the resulting temperature?
a) 12°C
b) 14°C
c) 16°C
d) 18°C
Answer: b) 14°C
50. What is the typical range of air pressure in the aircraft cabin during cruise?
a) 70-75 kPa
b) 75-80 kPa
c) 80-85 kPa
d) 85-90 kPa
Answer: b) 75-80 kPa
51. If the cabin volume is 350 cubic meters and the air change rate is 17 times per hour, what is the
total air flow rate in liters per second?
a) 1,458 L/s
b) 1,653 L/s
c) 1,847 L/s
d) 2,042 L/s
Answer: b) 1,653 L/s
52. What is the typical maximum allowed cabin altitude for unpressurized aircraft?
a) 10,000 feet
b) 12,500 feet
c) 15,000 feet
d) 17,500
