Avionics ventilation

Question 1

Avionics ventilation …

Answer 1

The ventilation system provides cooling through ambient air extraction, to limit the internal operating temperature of the electronic equipment (LH side).

Question 2

EXHAUST MODE - NORM

Answer 2

– On ground, ENG 1 off: extract fan on. OVBD valve full open, U/F valve closed
– Air/ground, ENG 1 on: extract fan operates. OVBD valve closed. U/F valve opened

Question 3

EXHAUST MODE - FAULT

Answer 3

Fan failure/ overheat (fan inhibited for 120 s. after eng start or after a GPU power on. AIR on CAP)

Question 4

EXHAUST MODE - OVBD

Answer 4

• extract fan off

- OVBD valve partially opened (in flight only). U/F valve closed

Question 5

OVBD VALVE

Answer 5

• AUTO except for emergency
• Direct control of OVBD valve.
• The full open position is possible only if the delta P is smaller than 1 PSI

Question 6

OVBD VALVE - FAULT

Answer 6

OVBD valve in disagreement with ovbd valve SW position