The cabin overhead ducting supplies cold air
through flexible tubes and nozzles to augment
cooling for the following components in the
avionics compartment:
• IRS units
• EFIS symbol generators
• MFD symbol generator
The IRS mounting trays contain fans that sup-
ply cooling air around the IRS units any time
power is on the aircraft, even when the cabin
air conditioning is not operating.
Three fans mounted on the floor forward of the
center pedestal cool the electronic display
units on the pilot and copilot instrument pan-
els. A vane switch airflow sensor is fitted to
the outlet duct of each fan. The fans supply
cooling air from the cockpit to the following
components:
• Left fan—Pilot’s EHSI and EADI
• Forward fan—MFD
• Right fan—Copilot’s EHSI and EADI
A COOL AIR FAIL warning light on each
main instrument panel and an AVIONICS
COOLING annunciator panel on each bulk-
head behind the pilot’s and copilot’s seat pro-
vide a warning and indication of failures
(Figure 16-70).
All fans operate automatically with power ap-
plied to the aircraft. If a cockpit fan fails, the
vane switch detects a loss of airflow and illu-
minates the relevant COOL AIR FAIL warn-
ing light and AVIONICS COOLING panel
warning indicator. Thermal switches inside
EFIS units trigger the relevant panel warning
indicator during an overheat. After an overheat
or cooling fan failure, the COOL AIR FAIL an-
nunciator cannot be reset until the fault clears.
CL 601-3A/R
16-81
FOR TRAINING PURPOSES ONLY
FlightSafety Canada
L t é e
L t d .
CL-600-2B16 PILOT TRAINING MANUAL
COOL
AIR
FAIL
EFIS 2 SG
O/HEAT
2
O/HEAT
FMC 2
O/HEAT
3
IND RESET
SYSTEM TEST
AVIONICS
COOLING
FAN FAIL
EFIS 2
IRU NO AIR
EFIS 1
SG O/HEAT
IRU 1
NO AIR
O/HEAT
O/HEAT
MFD
FMC 1
O/HEAT
FAN FAIL
IND RESET
SYSTEM TEST
AVIONICS
COOLING
FAN FAIL
EFIS 1 DU
MFD DU
Figure 16-70. Avionics Cooling Panel