Lights

Question 1

GEN 2 or GEN 3, GEN 4 or APU GEN OFF light on

Answer 1

Probable Cause:
Generator failure, off frequency, overvoltage, undervoltage, feeder fault, supervisory panel failure, transfer relay 2 or 3 failure, or associated bus monitoring switch OFF.

Note: if the APU generator control circuit breaker is out, the APU GEN OFF light will be on. Automatic APU load monitoring above 8,000 feet will be disabled; however, the generator will assume the load.

Action:
Use reset procedure, or place associated BUS MONITORING switch ON. If engine-driven generator light remains on steady throughout reset procedures, or goes out momentarily and comes back on, mission should be aborted.

Caution:
Generator supervisory panels shall not be exchanged until appropriate maintenance actions are performed.

Note: Ensure GEN 4 AUX CONT and GEN 4 TRANS circuit breakers are set appropriately.

Question 2

TRANSFORMER RECTIFIER OVERHEAT light on

Answer 2

Probable Cause:
Transformer Rectifier (TR) overheated

Action: Pull respective circuit breaker; No. 3 located at the flight station and Nos. 1 and 2 located at the main load center.

Question 3

EXTERNAL PWR AVAILABLE

Answer 3

Probable Cause:
Indicates electrical power is connected to the aircraft

Action:
Light will glow whether or not external power is selected.

Question 4

EXTERNAL PWR AVAILABLE light on (neon), but no power into aircraft

Answer 4

Probable Cause:
Wrong phase, nosegear uplock not properly positioned, battery not connected, generator No. 4 runaround feeder circuit breaker out, external power control circuit breaker out.

Action:
Move EXTERNAL POWER switch to RESET then ON. Check nosegear uplock position. Check battery condition. Check No. 4 runaround feeder circuit breaker. Check external power control circuit breaker.

B. U. P. E. R.

Question 5

EXTERNAL PWR AVAILABLE light on partial power into aircraft

Answer 5

Probable Cause:
Tranformer-rectifier No. 3 ganged circuit breaker out. ESSENTIAL DC BUS FEEDER circuit breaker No. 2 out. Monitorable Essential AC ganged circuit breaker behind copilot out. Monitorable Essential BUS switch off.

Action:
Check TR 3 circuit breaker. Check ESSENTIAL DC BUS FEEDER circuit breaker No. 2. Check Monitorable Essential AC ganged circuit breaker in. Check Monitorable Essential BUS switch.

32 MM

Question 6

EXTERNAL POWER light on

Answer 6

Probable Cause:
External power supplying power to aircraft system

Action:
EXTERNAL POWER switch is ON

Question 7

PRIMARY FUEL PUMP (parallel) light

No. 1, 2, 3, or 4 PRIMARY FUEL PUMP (parallel) light on during start (between 16 percent and 65 percent rpm)

Answer 7

Probable Cause:
Indicates the secondary fuel pump is functioning properly

Action:

Question 8

PRIMARY FUEL PUMP (parallel) light

No. 1, 2, 3, or 4 PRIMARY FUEL PUMP (parallel) light off during start (between 16 percent and 65 percent rpm)

Answer 8

Probable Cause:
Failure of secondary fuel pump.

Action:
Investigate

Question 9

PRIMARY FUEL PUMP (parallel) light

No. 1, 2, 3, or 4 PRIMARY FUEL PUMP light on, or momentarily on then off, above 65 percent rpm.

Answer 9

Probable Cause:

a. Failure of the primary pump
b. Fuel pumps are in parallel operations possibly due to a speed sense control malfunction

Action:
Pull FUEL SHUTOFF VALVE circuit breaker on START ESSENTIAL DC BUS.
a. If light remains on, reset the circuit breaker, and assume the primary pump has failed.
b. If the light goes out, leave the circuit breaker out, and assume a failure of either the 65 percent switch or the speed sense control. If mission is continued, refer to Speed Sense Control Malfunction, Paragraph 15.4

Question 10

No. 1, 2, 3, and 4 AUTO FEATHER lights are all on

Answer 10

Probable Cause:
The automatic feathering circuit has been armed.

Action:

Question 11

No. 1, 2, 3, or 4 AUTO FEATHER light on individually.

Answer 11

Probable Cause:
Propeller thrust has dropped to less than 500 pounds of positive thrust; propeller has automatically feathered.

Action:
Investigate

Question 12

No. 1, 2, 3, or 4 engine STARTER CONTROL VALVE OPEN light on

Answer 12

Probable Cause:
Engine starter control valve is open. (Valve should close and light go out when starter button is pulled out at 57 to 64 percent rpm during normal start.)

Action:
*If light remains on or comes on after start, secure engine by pulling emergency shutdown handle.

Question 13

No. 1, 2, 3, or 4 prop feather button light remains on

Answer 13

Probable Cause:
Indicates feather pump relay is closed, supplying electrical power to the feather pump.
Possible internal leakage. Incomplete pump cut-out circuit.

Action:

a. If light remains on following engine shutdown, pull respective propeller feather control circuit breaker, and execute the Emergency Shutdown procedure.
b. If light remains on following pressure cutout override, refer to In-Flight Restart Procedures

Question 14

FAN OUT light on

Answer 14

Probable Cause:
Cabin Exhaust fan is inoperative or lack of airflow

Action:
Open equipment doors for additional cooling. Use minimum electronic equipment. If EDCs are inoperative (no air-conditioning available), open AUX vent.

Question 15

EDC TEMP HIGH light on.

Answer 15

Probable Cause:
EDC oil temperature excessive. Low oil level in sump. High engine oil temperature.

Note: Low intensity illumination of the EDC TEMP HIGH light is acceptable unless accompanied by a master PRESS SYS light.

Action:

a. Check engine oil temperature; if high, correct.
b. If unable to control, disconnect, monitor for loss of spread, dump, continue operation.

The DISCONNECT position shall be selected only when the engine is operating in the normal RPM range.

Caution: Disconnecting the EDC outside of normal engine RPM range will damage the compressor.

c. If spread is indicated after disconnect, execute the Emergency Shutdown procedure. If the engine is allowed to operate due to a greater emergency, the EDC should be dumped.
d. Refer to Air-Conditioning system Malfunction

Question 16

EDC PRESS LOW light on

Answer 16

Probable Cause:
EDC oil pressure is low. Low level in sump. EDC drive shaft sheared.

Action:

a. With loss of spread, disconnect and dump EDC. Continue operation.
b. If spread is indicated, disconnect, monitor for loss of spread, dump. Continue operation.

The DISCONNECT position shall be selected only when the engine is operating in the normal RPM range.

Caution: Disconnecting the EDC outside of normal engine RPM range will damage the compressor.

c. If spread is indicated after disconnect, execute the Emergency Shutdown procedure. If the engine is allowed to operate due to a greater emergency, the EDC should be dumped.

Note: If on ground and mission is continued: Ensure Normal RPM is selected and ground air conditioning on prior to disconnect.

d. Refer to Air-Conditioning system Malfunction

Question 17

REFR OVHT (overheat) light on

Answer 17

Probable Cause:
Temperature in cooling duct exceeds safe limits. On ground: inoperative heat exchanger blower fan.

Action:
In flight, dump EDC. After light is out, operation is permitted in the manual mode at the two-dot position or warmer.
On deck, turn off GRD AIR COND switch; investigate by checking the HEAT EXCHANGER cbs on BUS B and BLOWER CONT cb on MEDC. If cbs are set and the light is out, operation is permitted in the manual mode two-dot position or warmer.

Question 18

L WING HOT or R WING HOT light on

Answer 18

Probable Cause:
Air temperature in the wing plenum exceeds safe limits. May be caused by a leak in the bleed air manifold or EDC plumbing.

Action:

a. Secure wing deicing and get out of icing area.
b. If light remains on, dump appropriate EDC

Question 19

LEAK TEST ACCEPT light

Answer 19

Probable Cause:

Action:
Maintenance function. Refer to appropriate maintenance manuals.

Question 20

No. 1, 2, 3, and 4 engine bleed air valve open lights on.

Answer 20

Probable Cause:
When the valve begins to open, the light will be on. When the valve is closed, the light should be off.

Action:

Question 21

Left and right FUS BLEED SHUT-OFF valve OPEN lights on.

Answer 21

Probable Cause:
When the valve begins to open, the light is on. When the valve is closed, the light should be off.

Action:

Question 22

LE HOT light on

Answer 22

Probable Cause:
The wing leading edge skin temperature has increase in excess of 110C. One of the six modulating valves is either stuck open or improperly modulating.

Action:
Close all bleed air valves. Locate defective area with temperature selector. Open all modulating valves. When necessary, deice the entire wing using the bleed air valves.

Question 23

EMP DE-ICE light on

Answer 23

Probable Cause:
Parting strip power relay deenergized, cycling power relay deenergized, control relay deenergized, timer motor failure, empennage overheat condition. Open control power circuit breaker.

Action:
Turn switch OFF then ON. If light remains on, turn switch OFF, increase airspeed above 200 KIAS; vacate icing area. If light does not come back on, a temporary overhead condition exists. Continue operation.

Question 24

ANTI-ICING light

No. 1, 2, 3, or 4 engine ANTI-ICING advisory light on with control switch on.

Answer 24

Probable Cause:
Fourteenth stage air of sufficient temperature to melt ice has entered the torquemeter shroud and the inlet scoop.

Action:

Question 25

ANTI-ICING light

No ANTI-ICING advisory light with control switch on.

Answer 25

Probable Cause:
One of both areas of system may not be receiving hot air.

Action:
a. Check for horsepower drop. If normal, continue operation.
b. If less than normal:
Check for ice buildup on air inlet scoop. If excessive, execute the Emergency Shutdown procedure.

If no ice buildup on air inlet scoop is observed, monitor shp, TIT, and fuel flow. Initial indications may be a gradual power loss followed by erratic operations. If either of these indications is observed, execute the Emergency Shutdown procedure.

Question 26

ANTI-ICING light

ANTI-ICING advisory light on and control switch off

Answer 26

Probable Cause:

a. Abnormal heat in the area
b. Loss of electrical power to the solenoid valve.

Action:
On deck, investigate, secure engine, and return to the line.

In flight, turn on anti-ice control switch.

a. If a shp drop is observed, execute the Emergency Shutdown procedure.
b. If no shp drop is observed, continue engine operation.

Question 27

ANTI-ICING light

ANTI-ICING advisory light remains on after system utilization

Answer 27

Probable Cause:
Failure of one or both thermal switches and/or anti-icing valves

Action:
Allow sufficient time for thermal switch cooling prior to investigating. If no other abnormal indications exist, engine operation may be continued for the remainder of the flight.

Question 28

Windshield head CYCLING lights on (neon)

Answer 28

Probable Cause:
Indicates that electrical power is being supplied to the windshield panels. When lights are out, electrical power is cycled off.

Action:
If unable to start cycling on a cold windshield, use OVERRIDE switch.

Question 29

Side windshield head FAIL light on

Answer 29

Probable Cause:
Windshield power relay and/or overheat control relay stuck in energized position when control switch off.

Action:
Pull side windshield head power circuit breaker on main AC BUS A

Question 30

L or R HTR OUT pitot head out light on

Answer 30

Probable Cause:
Indicates electrical current flow to the pitot heater element has been interrupted, or current flow detector is inoperative.

Action:
Check respective circuit breaker and bus. Monitor equipment for proper operation.

Question 31

No. 1, 2, 3, or 4 feather valve and NTS lights on.

Switch in NTS position

Answer 31

Probable Cause:
NTS has occurred

Action:
Reset by putting switch to FEATHER VALVE position and back to NTS position

Question 32

No. 1, 2, 3, or 4 feather valve and NTS lights on

Switch in FEATHER VALVE position

Answer 32

Probable Cause:
Feather valve is being mechanically positioned to the feather position by NTS action during an NTS check (flashing light), or by the emergency shutdown handle when pulled (steady light).

Action:

Question 33

DOORS light on

Answer 33

Probable Cause:
Intake or exhaust door open (Should close when APU is shut down)

Action:
Do not exceed 225 KIAS

Question 34

ARMED light on

Answer 34

Probable Cause:
Arming switch on

Action:
If APU is not being used in flight, turn arming switch off.

Question 35

No. 1, 2, 3, or 4 FILTER light on.

Answer 35

Probable Cause:
One or both of the low pressure fuel filters are restricting flow.

Action:
If engine continues to function normally, continue engine operation.

Question 36

No. 1, 2, 3, or 4 PRESS LOW light on.

Answer 36

Probable Cause:
Indicates the differential pressure across the corresponding engine-driven centrifugal boost pump is low. A flickering light indicates at partial obstruction of the fuel line.

Note: The fuel PRESS LOW light should be out by low rpm. After start, possible faulty or stuck pressure switch.

Action:

a. If fuel flow and quantity of the corresponding engine are normal and engine continues to operate normally, inspect nacelle for visible fuel. If fuel is visible, secure engine.
b. In flight, if no visible, continue operation, observing engine closely.
c. During ground operations, if no fuel is visible, cycle respective boost pump or shift engine to normal rpm. If light goes out and remains out, continue operation.

Question 37

No. 1 2, 3, or 4 TANK shutoff valve advisory lights on.

Answer 37

Probable Cause:
Light will illuminate whenever the corresponding tank valve position does no coincide with the tank valve switch. Failure of the valve to open or close completely energizes the light.

Action:
Investigate.

Question 38

No. 1, 2, 3, or 4 XFEED valve advisory lights on.

Answer 38

Probable Cause:
Light will illuminate whenever the corresponding tank valve position does no coincide with the tank valve switch. Failure of the valve to open or close completely energizes the light.

Action:
Investigate

Question 39

Cross-ship XFEED valve advisory light on.

Answer 39

Probable Cause:
Light will illuminate whenever the corresponding tank valve position does no coincide with the tank valve switch. Failure of the valve to open or close completely energizes the light.

Action:
Investigate

Question 40

RESET advisory light on.

Answer 40

Probable Cause:
Light will illuminate whenever the refuel control panel has control of the transfer valves, which are also used to refuel tank Nos. 1, 2, 3, 4.

Action:
Push reset button to regain control of transfer valves.

Question 41

Tank BOOST pump low pressure advisory light on.

Answer 41

Probable Cause:
Light will illuminate whenever the output pressure of the corresponding boost pump is low.

Action:
Refer to Fuel Boost Pump Failure

Question 42

Transfer pumps PRESS LOW advisory lights on

Answer 42

Probable Cause:
Tank No. 5 is empty or pump output pressure is low.

Action:
Shut off respective pump; refer to Transfer Pump Failure, Tank 5

Question 43

GEN mechanical failure light No. 2, 3, or 4 on (steady or intermittent)

Answer 43

Probable Cause:
Primary generator drive end bearing has failed.

Action:
Mission should be aborted. If the generator switch must be left in the OFF position because of a generator malfunction, execute the Emergency Shutdown procedure.

Question 44

CHIPS light No. 1, 2, 3, or 4 on (steady or intermittent).

Answer 44

Probable Cause:
Metal particles on magnetic plug in power section or gearbox.

Action:
Check for secondary indications. If noted, execute Emergency shutdown procedure. If no secondary indications are present, engine operation may be continued. Refer to Magnetic Chip Detector Indication

Question 45

OIL HOT light No. 1, 2, 3, or 4 engines on.

Answer 45

Probable Cause:
Engine oil temperature 100C or over.

Action:
If power levers in the ground (BETA) range, open inducers to decrease temperature. If power levers are in flight (ALPHA) range, 100C for 5 minutes, then 90C. Control oil cooler flaps position. If unable to control, secure engine.

Question 46

OIL PRESS light No. 1, 2, 3, or 4 engine on.

Answer 46

Probable Cause:
Either engine oil pressure is below 40 psi or gearbox pressure below 130 psi.

Action:
Low rpm, light normal. In flight check oil pressure gauges; investigate. If oil pressure is within limits, continue operation. If out of limits, execute the Emergency Shutdown procedure.

Question 47

PROP PUMP No. 1 light (1, 2, 3, or 4 engine) on.

Answer 47

Probable Cause:
Reduced flow and drop in pressure from prop pump 1 due to pump failure, obstruction, or low oil level.

Action:
If either or both propeller pump caution lights illuminate: Continue normal engine operation and refer to Propeller Malfunctions.

Question 48

PROP PUMP No. 2 light (1, 2, 3, or 4 engine) on.

Answer 48

Probable Cause:
Reduced flow and drop in pressure from prop pump 2 due to pump failure, obstruction, or low oil level.

Action:
If either or both propeller pump caution lights illuminate: Continue normal engine operation and refer to Propeller Malfunctions.

Question 49

BETA light No. 1, 2, 3, or 4 prop on.

Answer 49

Probable Cause:
Blade angle at 10 degrees or less.

Action:

Question 50

FUS DUCT HOT light on

Answer 50

Probable Cause:
Leak in area around crossship manifold, creating excessive temperature. Can be cause by a leak in the bleed air manifold, APU bleed air lines or EDC plumbing.

Action:

• 1. On ground, secure ground air-conditioning and all engines and APU bleed air, and return to the line.
• 2. In flight, close all engine bleed and fuselage shutoff valves.
     
     3. If light remains on, dump EDCs one at a time.
     4. If light remains on, land as soon as possible.

Question 51

CABIN PRESS light on.

Answer 51

Probable Cause:
Light on at cabin altitude 10,000 (+-500) feet. CABIN PRESS light out by 8,000 feet on descent.

Action:
Refer to Pressurization Loss

Question 52

Master DE-ICING light on.

Answer 52

Probable Cause:
Alert or fault in deicing system or bomb bay heating system (L or R WING HOT, LE HOT, EMP DEICE, L or R pitot heater, or BOMB BAY HOT or COLD).

Action:
Look for cause in deicing systems on overhead anti-icing control panel. Activate system or secure if necessary. Reset for continued warning protection. Get out of icing area if system is critical and inoperative.

Question 53

Master ELEC POWER light on.

Answer 53

Probable Cause:
Generator No. 2, 3, or 4 OFF light is on. Overheat of TR No. 1, 2, or 3.

Action:
Locate fault on overhead panel. Secure faulty system. Reset for continued warning protection.

Question 54

Master RACK OVHT light on.

Answer 54

Probable Cause:
Electronic rack overheat condition exists. Also comes on during MAIN DC BUS failure. The ASH-33 (DMTS) will cause a rack overheat indication when the system is initially turned on, or will illuminate continuously when a loss of airflow is detected.

Action:
Initiate Fire of Unknown Origin checklist/procedures. Locate overheated electronic bay(s) by illuminated individual bay overheat light(s). Provide required cooling or secure equipment as necessary.

Question 55

IFF light on. (Operational only if KIT-C transponder computer is installed.)

Answer 55

Probable Cause:
Mode 4 zeroized, self-test function of computer has detected a faulty computer, transponder not replying to proper Mode 4 interrogations.

Action:
Ensure MASTER switch in NORM, Mode 4 toggle switch ON, and proper code selected. If light persists, fly selected operational procedure for inoperative tactical IFF.

Question 56

START VALVE light on.

a. During start sequence (normal).
b. After start sequence or during engine operation (abnormal).

Answer 56

Probable Cause:
Indicates on of the four engine start control valves is open.

Action:
* Check overhead panel for individual engine start control valve open light.

Question 57

AUTOPILOT/RAWS flashing red warning lights (glareshield) with synchronized tone.

Answer 57

Probable Cause:
RAWS warning: loss of ac power to radar altimeter. Unreliable radar altimeter signal. Aircraft descending through 380 (+-20) feet (3-second warning) or 170 (+-10) feet (continuous warning). (All warnings are cancelled when nosegear is down and locked or flaphandle is below MANEUVER.)

Action:
If warning is abnormal, investigate.

Question 58

FLAP ASYM light on.

Answer 58

Probable Cause:
Flap asymmetry system has tripped. If there has been a multiple flap component failure, the flaps may still be moving or could be moved by use of the flap handle.

Action:

a. ) If accompanied by a change in flight characteristics, execute Split-Flap Procedures.
b. ) If not, place flap handle in best corresponding to flap position. (Does not need to be in detent)
c. ) Refer to Split-Flap procedures.

Question 59

DOOR OPEN light on.

Answer 59

Probable Cause:
Cabin door (either section), hydraulic service center door is not locked.

Action:
Lock the door.

Question 60

RUDDER POWER light on (flaps up).

Answer 60

Probable Cause:
No. 1 hydraulic system pressure failure. Shutoff valve has opened.

Action:
Actuate rudder pedals to deplete residual No. 2 hydraulic system pressure in the rudder boost package.

If the light remains on:

a. ) Check the rudder boost shutoff valve circuit breaker (K13)
b. ) Turn off the No. 2 hydraulic pump. If the warning light goes out, the shutoff valve is inoperative. Turn the No. 2 hydraulic pump on a make no abrupt rudder movements.

Question 61

AUTO TRIM light on

Answer 61

Probable Cause:
Indicates the auto pitch trim system has failed. This will also cause the pitch trim off flag to appear in the 3-axis trim indicator.

Action:
Disengage autopilot. Reset autotrim system by pulling the three AC autopilot circuit breakers and resetting one time only. If failure persists, extinguish light with AUTO TRIM LT OVERRIDE switch. Lights automatically resets when flaps extended. Check 3-axis trim indicator before disconnecting autopilot.

Question 62

HYD PRESS light.

No. 1 or 1A HYD PRESS light on.

Answer 62

Probable Cause:
Respective pump output pressure is below 1,800 psi.

Action:
Turn off the respective pump; investigate.

Note:
Gear retraction with one operable hydraulic pump may result in indication of hydraulic system failure and unsafe gear due to heavy system demand.

Question 63

HYD PRESS light.

No. 2 HYD PRESS light on.

Answer 63

Probable Cause:
No. 2 pump output pressure is below 1,800 psi.

Action:
Check No. 2 system pressure. If low, secure No. 2 pump.

Question 64

No. 1, 1A, or 2 HYD OIL HOT light on

Answer 64

Probable Cause:
Hydraulic oil temperature is excessive, restricted coolant flow, not enough fuel in respective inboard fuel tank (minimum 1,000 lb).

Action:
Turn off respective pump.

Question 65

NTS INOPR

Answer 65

Probable Cause:
Inoperative NTS System.

Action:

1. ) Continue holding out on feather button.
2. ) Emergency shutdown handle - Pull.
3. ) Feather button - Push.

Question 66

ICING light on.

Answer 66

Probable Cause:
Indicates the ice detector probe is accumulating ice. The frequency of the light indicates the amount of ice buildup. Long “off” period indicates a slow buildup. Light may illuminate at high angles of attack.

Action:
Anticipate icing conditions.