Environmental, Pressurization, & Pneumatics

Question 1

What is the maximum altitude for flight and maintain the Pressurization System within normal operating limits

Answer 1

35,000, this will have the cabin differential at 6.6 PSI and maintaining a cabin pressure of 10,380 (comply with AR 95-1)

Question 2

In a LOAD SHED condition, is it possible to maintain flight at 35,000 feet, when considering pressurization

Answer 2

Yes, The left bleed air valve is fully functional and one engine should be capable of maintaining pressurization.

Question 3

What is the maximum cabin differential pressure for the MC-12

Answer 3

6.6 PSI

Question 4

What is the minimum N1 to operate the air conditioning

Answer 4

62 % N1 on the right engine, less than that the Air Cond N1 Low advisory light will illuminate and the air conditioner will be inoperative.

Question 5

After selecting the bleed air valve to pneumatic and environmental off after illumination of a single [L or R BLEED FAIL] red master warning annunciator, the annunciator will?

Answer 5

Remain illuminated

Question 6

What is regulated pneumatic air pressure used for?

Answer 6

surface de-ice,
vacuum,
hydraulic head pressure,
door seal,
bleed air warning,
flight hour meter.

Question 7

Regulated pneumatic air is ____ psi with overpressure relief at ____ psi?

Answer 7

18, 21.

Question 8

P3 air is _____ degrees off the 4th stage compressor and cools to ____ degrees above ambient before entering the 18 psi pressure regulator.

Answer 8

700 degrees

70 degrees

Question 9

What device controls the flow of bleed air and ambient air.

Answer 9

The Flow Control Unit (FCU)

Question 10

The flow control unit regulates _____________ into the pressure vessel.

a. Inflow air.
b. Outflow air.
c. Ram air.
d. Vacuum air.

Answer 10

a. Inflow air.

Question 11

What are the five primary components in the Pressurization System.

Answer 11

Pressurization Controller
System Switches
Indicators
Outflow Valve
Safety Valve

Question 12

The pressure controller uses __________ to open the outflow valve for scheduled pressurization.

a. Pressurization air.
b. Waveguide air.
c. Vacuum
d. Electricity.

Answer 12

c. Vacuum

Question 13

What are two major functions of the outflow valve?

Answer 13

Two major functions –

Modulates pressurization
Negative Pressure Relief
Maximum Pressure Relief is capped

Question 14

From the list below, which is NOT a function of the outflow valve?

Positive Relief.
Negative Relief.
Dump Operations.
Pressure Modulation.

Answer 14

Dump Operations.

Question 15

During the pressurization test what valve closes when we place the switch to test?

a. Safety valve.
b. Outflow valve.
c. Motive flow valve.
d. One way check valve.

Answer 15

a. Safety valve.

Question 16

What prevents “pressure bumps” from occurring after takeoff?

a. The Left and Right Air-to-Air Heat Exchangers.
b. The Normally Closed Solenoid and Safety valve.
c. The Normally Open Solenoid and Outflow valve.
d. The left landing gear safety switch and 6 – 8 second delay that opens up the right FCU ambient air valve.

Answer 16

d. The left landing gear safety switch and 6 – 8 second delay that opens up the right FCU ambient air valve.

Question 17

Which valve modulates to maintain scheduled pressurization in flight?

a. Outflow valve.
b. Safety valve.
c. Motive flow valve.
d. One way check valve.

Answer 17

a. Outflow valve.

Question 18

What cabin altitude does the Cabin Altitude white annunciator come on?

Answer 18

When the cabin altitude exceeds 10,000 feet MSL.

Question 19

What cabin altitude does the Can ALT HIGH RED Warning come on?

Answer 19

When the cabin altitude exceeds 12,000 feet MSL.

Question 20

What cabin altitude drops the passenger oxygen masks?

Answer 20

Cabin Altitude greater than 12,500 ft the passenger oxygen masks will drop down.

Question 21

Explain the Cabin Diff HI Warning.

Answer 21

Cabin Pressure is greater than 6.9 PSI.

Question 22

Analyze the following scenario and select the best answer:

You are flying along and you experience a complete electrical failure. What will happen with regards to pressurization?

The aircraft will attempt to over pressurize.

The aircraft will immediately dump the cabin.

The aircraft will maintain scheduled pressurization.

The aircraft will depressurize at the cabin leak rate.

Answer 22

The aircraft will depressurize at the cabin leak rate.

Question 23

What are the Unregulated 120 PSI Users?

Answer 23

Brake Deice (if installed)
18 psi Regulator

Question 24

What are the Regulated 18 psi users?

Answer 24

Regulated 18 psi users
Flight hour meter
Bleed Air Warning
Hydraulic fill can
Ejector (creates vacuum)
Pressurization control
Deice boots

Question 25

Where is vacuum obtained?

Answer 25

Vacuum is obtained from pneumatic air passing through the vacuum ejector.

Question 26

How many users of vacuum are there? What are they?

Answer 26

Vacuum is provided for the deice boots and the pressurization control system.

Question 27

Question: After selecting the bleed air valve to pneumatic and environmental off after illumination of a single [L or R BLEED FAIL] red master warning annunciator, the annunciator will?

Answer 27

Answer: Remain illuminated.

Question 28

Question: Regulated pneumatic air is ____ psi with overpressure relief at ____ psi?

Answer 28

Answer: 18, 21.

Question 29

Question: What is regulated pneumatic air pressure used for?

Answer 29

Answer: Vacuum, hydraulic head pressure, door seal, bleed air warning, flight hour meter.

Question 30

Question: Is Brake Deice available during single engine operations?

Answer 30

Answer: No.

This is because the check valves do not allow unregulated P3 air to the opposite brake manifold.

Question 31

What is a more efficient means of cooling the aircraft while on the ground?

Answer 31

Leave the Bleed Air Valves switches in the ENVIRO OFF position.

Question 32

True or False –

The Air-to-Air Heat Exchangers have a bypass capability?

Answer 32

True

Question 33

True or False –

The temperature of the air coming into the cabin when in the MAN mode is controlled by the floor sensors.

Answer 33

False

Question 34

What is the CAUTION associated with using the INCR / DECR in the MAN mode?

Answer 34

INCR / DECR switch activation longer than 2-3 second intervals or longer than 60 seconds can result in duct overheating and the illumination of the amber DUCT OVERTEMP annunciator.