Pressurization

Question 1

Where are the Outflow (OFV), Pressure Relief (PRV), and Negative Pressure Relief (NPRV) valves located?

Answer 1

Aft cabin pressure bulkhead

Question 2

What is the cockpit indication of the Outflow Valve position?

Answer 2

Environmental Synoptic Page

Question 3

What is the primary difference between the two pressurization ECMU (Electronic Control and Monitoring Unit) channels?

Answer 3

One channel controls the Outflow Valve automatically. The other channel controls the Outflow Valve manually through the MAN position of the PRESN MODE switch.

Question 4

Do both pressurization ECMU channels (controlling AUTO and MAN) provide Cabin Altitude limit protection?

Answer 4

Yes

Question 5

What actions occur when the PREN DUMP button is pushed?

Answer 5

-Outflow Valve opens
-Recirculating/Evaporator fans are disabled

Question 6

What is the maximum cabin altitude allowed by each pressurization ECMU channel, including a situation where the PRESN DUMP button is pushed? Auto vs. Manual

Answer 6

-AUTO Mode: 12,000’
-MAN Mode: 14,500’

Question 7

Under what conditions does the Red CAB ALTITUDE HI (CAS) illuminate when the aircraft altitude is below 25,000’?

Answer 7

LFE (MSL) CABIN ALTITUDE
<8,300’ 10,000’
8,300-9,600’ 11,500’
>9,600’ 14,200’

Question 8

Under what conditions does the Red CAB ALTITUDE HI (CAS) illuminate with the aircraft altitude above 25,000’?

Answer 8

Cabin Altitude >10,000’