Beechcraft C-12C Operator And Technical Reference Manual page 897

9-16. DUCT OVERTEMP
ILLUMINATED.
Ensure the cabin floor outlets are open and
unobstructed and perform the following steps in
sequence until the light is extinguished.
approximately 30 seconds after each adjustment for
the system temperature to stabilize.
temperature condition is considered corrected at any
point during the procedure that the light goes out.
1. CABIN AIR control – In.
2. CABIN AIR/TEMP MODE switch – AUTO.
3. CABIN AIR/TEMP switch – Decrease.
4. VENT BLOWER switch – HI.
5. CABIN AIR/TEMP MODE switch – MAN
COOL.
6. MANUAL TEMP switch – DECREASE
(hold).
7. LEFT BLEED AIR VALVE switch – PNEU
& ENVIRO OFF.
8. Light still illuminated (30 seconds) LEFT
BLEED AIR VALVE switch – OPEN.
9. RIGHT BLEED AIR VALVE switch –
PNEU & ENVIRO OFF.
10. Light still illuminated (30 seconds) RIGHT
BLEED AIR VALVE switch – OPEN.
NOTE
If the over temperature light has not
extinguished after completing the above
procedure, the warning
malfunctioned.
9-17. ICE VANE FAILURE.
Ice vane failure is indicated by a VANE FAIL
caution light illumination. If an ice vane fails to operate
electrically, perform the following:
CAUTION
Do not operate vanes electrically after
manual extension.
1. Airspeed – 160 KIAS or below.
2. ICE VANE CONTR circuit breaker – Pull.
CAUTION LIGHT
9-18. ENGINE
Allow
MALFUNCTION.
The over
Steady illumination of the warning light in flight
indicates a possible ruptured bleed-air line aft of the
engine firewall. The light will remain illuminated for the
remainder of flight. Perform the following:
differential pressure exceeds 6.1 psi
psi
system has
3. ICE VANE – Operate manually.
4. Airspeed – Resume normal airspeed.
BLEED
a. BLEED AIR FAILURE Light Illuminated.
NOTE
BLEED AIR FAIL annunciators
momentarily illuminate
simultaneous surface deice and brake
deice operation at low N
1. BRAKE DEICE switch – Off.
2. TGT and TORQUE – Monitor (note
readings).
3. BLEED AIR VALVE switch – OFF.
NOTE
Brake deice, on the affected side, and
rudder boost will not be available with
BLEED AIR VALVE switch off.
4. Cabin pressurization – Check.
b. Excessive Differential Pressure.
T2 , perform the following procedure:
1. Cabin pressurization controller – Select
higher setting.
IF CONDITION PERSISTS:
2. Oxygen (crew and passengers) – As
required.
3. LEFT BLEED AIR VALVE switch –
ENVIRO OFF (light illuminated).
IF CONDITION STILL PERSISTS:
4. RIGHT BLEED AIR VALVE switch –
ENVIRO OFF (light illuminated).
5. Descend – As required.
TM 1-1510-218-10
AIR SYSTEM
may
during
speed.
1
If cabin
C D T1 and 6.5
9-7