SYS - Environmental 2 Flashcards
(37 cards)
What engine bleed port used for pressurisation system?
P3
What areas ensure the cockpit is pressurised sealed? (4)
- firewall
- AFT pressure bulkhead
- pressure flooring
- canopy pressure seal
The __________ ___________ _____________ in the AFT pressure bulkhead monitors cockpit pressure and automatically adjusts the position of the ____________ ____________ __________.
Control valve regulator
Pressurisation control valve
What altitudes is the cockpit pressure controlled to from sea level up to 31000ft?
From 8000ft cockpit PA it holds cockpit PA at 8000ft until 3.6 +/- 0.2 PSI at 18069 ft. then maintains this differential until 31000ft where a cockpit PA of 16600ft is experienced.
What measures cockpit pressure differential?
Delta p regulator on aft pressure bulkhead
When does safety valve open?
4.0 PSI
When does the dump solenoid open the pressurisation control valve?
With weight on wheels
Three positions of the pressurisation switch? And what do they do?
- norm
- dump (terminates power to dump solenoid opening pressurisation control valve. Fresh air valve remains closed and no ram air to cockpit)
- dump/ram (same as dump position but fresh air valve is opened. Defog valve automatically turned off)
Will bleed air still flow into the cockpit when pressurisation switch in either dump or dump/ram?
Yes - unless BLEED AIR INFLOW switch is in off
When does yellow CKPT ALT caution message appear?
> 19000 cockpit PA
When does red CKPT PX appear?
3.9-40psid +/- 0.1
What valve does the BLEED AIR INFLOW switch control?
Pneumatic system shutoff valve
What two components does the Bleed air go through after the firewall before being hooked up to the anti-g suits?
- water separator
- safety valve (7psi)
Basic operation of the anti g valve?
Weight rod and orifice
What button is pressed to test the g suit?
HI FLOW
Where does OBOGS get its bleed air from? Is it a separate port?
P3 left side, yes.
How does the OBOGS system generate oxygen?
Extracts it from the conditioned engine Bleed air
What two safety switches does OBOGS have?
- height temperature
- low pressure
Where is OBOGS unit?
Fuselage right side avionics bay
What does the concentrator do in the OBOGS unit do?
Automatically adjusts the oxygen pressure concentration for the current altitude based on current cockpit pressure
What does the plenum function as between the OBOGS unit and the regulators?
Acts as a holding tank
In event of OBOGS failure how much oxygen does the plenum provide?
Approximately on breath depending on cockpit pressurisation, aircraft PA, regulator settings and pilot demand.
The occupy Ben pressure regulator supply lever controls? (2)
- system electrical power
- oxygen flow
Which oxygen pressure regulator supply lever has priority?
If either is on, OBOGS is operative. Both must be off for the system to be off. Respective supply lever must be on to revive oxygen in each cockpit.
