Caution/Warning Lights Panel Flashcards
For each caution or warning light, know the probable cause and immediate action.
Probable Cause: The rear fuselage has contacted the runway during takeoff or landing due to excessive nose up attitude.
Immediate Action: Refer to the “TOUCHED RUNWAY” warning light checklist in Ch. 14 of the QRH.
Remarks: If indication occurs during takeoff do not pressurize the cabin. Return for landing as soon as practicable. Maintenance action required before next flight. This light is not applicable to the 100 series.
Probable Cause: The forward exit door is not properly secured.
Immediate Action: Refer to the “FWD EXIT DOOR” warning light checklist in Ch. 4 of the QRH.
Remarks: Warn all personal to stay clear of the door. The light will go out when the door is properly secured. This light is not applicable to the 100 series.
Probable Cause: The service door is not properly secured.
Immediate Action: Refer to the “SERVICE DOOR” warning light checklist in Ch. 4 of the QRH.
Remarks: Warn all personal to stay clear of the door. The light will go out when the door is properly secured. This light is not applicable to the 100 series.
Probable Cause: Cabin altitude exceeds 10,000 feet.
Immediate Action: Check FAULT light on CABIN ALTITUDE panel for illumination. If illuminated, select pressurization mode selector switch to MAN and BLEED selector to MAX. Regulate cabin altitude by manipulation of MAN knob on CABIN ALTITUDE panel. If FAULT light is not illuminated, select BLEED selector to MAX and see the QRH for inflight depressurization procedure.
Remarks: CABIN PRESS caution light goes out when cabin pressure goes below 10,000 feet.
Probable Cause: Flight compartment supply duct exceeds 88ºC.
Immediate Action: If the caution light repeatedly illuminates and goes out, adjust FLT COMP TEMP CONTROL to a lower setting. If cycling continues, bleed switch off.
Remarks: Normal operation is automatically interrupted and full cool air is routed through ducts until duct temperature is 82ºC. Caution light goes out and normal operation resumes.
Probable Cause: Cabin supply duct temperature exceeds 88ºC.
Immediate Action: If the caution light repeatedly illuminates and goes out, adjust CABIN TEMP CONTROL to a lower setting. If cycling continues, bleed switch off.
Remarks: Normal operation is automatically interrupted and full cool air is routed through ducts until duct temperature is 82ºC. Caution light goes out and normal operation resumes.
Probable Cause: Air cycle machine (ACM) compressor discharge temperature exceeds 207ºC.
Immediate Action: Gradual depressurization will occur while bleed air supply is shut down. If the caution light repeatedly illuminates and goes out, reduce ACM cooling demand by adjusting CABIN temperature control to a warmer setting. If cycling continues, turn bleed switches off.
Remarks: Normal operation is automatically interrupted and both bleed air sub-systems are shut down until the ACM cools. Caution light goes out and normal operation resumes. This light is not applicable to the Model 311.
Probable Cause: The flight compartment Air Cycle Machine (ACM) compressor discharge temperature is too hot.
Immediate Action: Refer to “FLT COMPT PACK HOT” caution light checklist in Ch. 4 of the QRH.
Remarks: Normal operation is automatically interrupted and the flight compartment pack is automatically shut down until the ACM cools. Then the caution light goes out. If the pack switch remains in the AUTO or MAN position, the pack operates again. This light is not applicable to the 100 series.
Probable Cause: The cabin Air Cycle Machine (ACM) compressor discharge temperature is too hot.
Immediate Action: Refer to “CABIN PACK HOT” caution light checklist in Ch. 4 of the QRH.
Remarks: Normal operation is interrupted and the cabin pack is automatically shut down until the ACM cools. Then the caution light goes out. If the pack switch remains in the AUTO or MAN position, the pack operates again. This light is not applicable to the 100 series.
Probable Cause: Primary inverter inoperative.
Immediate Action: Check the left essential DC circuit breaker panel PRI INV PWR and CONT circuit breakers (F8, G8). Refer to QRH Ch. 9. Primary inverter off and select aux inverter to L.
Remarks: With only one inverter operational (two inverters inoperative), power is maintained to all fixed frequency buses via the bus tie circuit breaker. Shed loads where possible to minimize load on the remaining inverter.
Probable Cause: Auxiliary inverter inoperative.
Immediate Action: Check the left main DC circuit breaker panel AUX INV PWR and CONT circuit breakers (D8, E8). Auxiliary inverter switch off.
Remarks: With failure of primary or secondary inverter, the auxiliary inverter automatically switches to the failed side, regardless of AUX INV switch position.
Probable Cause: The stick pusher computer detects a malfunction or the STICK PUSHER SHUT OFF switchlight has been pushed.
Immediate Action: Refer to “STICK PUSHER FAIL” caution light checklist in Ch. 13 of the QRH.
Remarks: If the light illuminated as a result of the STICK PUSHER SHUT OFF switchlight being pushed, push it again to cause the caution light to turn off. This light is not applicable to the 100 series.
Probable Cause: There is a possible DC bus fault.
Immediate Action: Refer to “DC BUS” caution light checklist in Ch. 9 of the QRH.
Remarks: The BBPU presents buses from tying. After 7-10 seconds, it shuts down the related DC generator and removes the related battery from the faulty main bus. All services on the related main DC bus are lost. The BBPU has reduced an excessive overload output from a DC generator.
Probable Cause: There is a hydraulic pressure loss to the inboard or outboard roll spoiler actuators.
Immediate Action: Refer to “ROLL SPLR INBD HYD” or “ROLL SPLR OUTBD HYD” caution light checklist in Ch. 10 of the QRH.
Remarks: Illumination of the ROLL SPLR INBD HYD caution light at an airspeed above 135 knots may be indicative of a spoiler cable failure. If both “ROLL SPLR INBD HYD” and “ROLL SPLR OUTBD HYD” caution lights illuminate that indicates a possible spoiler cable failure.
Probable Cause: Left 26 volt fixed frequency transformer inoperative.
Immediate Action: Check avionics circuit breaker panel L26V FAIL circuit breaker (P1). Auxiliary inverter select to operating side.
Remarks: None.
Probable Cause: Right 26 volt fixed frequency transformer inoperative.
Immediate Action: Check avionics circuit breaker panel R26V FAIL circuit breaker (P2). Auxiliary inverter select to operating side.
Remarks: None.
Probable Cause: Left AC variable frequency bus not powered.
Immediate Action: None.
Remarks: If an AC generator fails, left and right AC variable frequency buses automatically tie.
Probable Cause: Right AC variable frequency bus not powered.
Immediate Action: None.
Remarks: If an AC generator fails, left and right AC variable frequency buses automatically tie.
Probable Cause: Left TRU inoperative.
Immediate Action: Check L TRU circuit breaker on 115V AC VARIABLE FREQUENCY circuit breaker panel.
Remarks: Secondary DC buses tie in the event of a TRU failure. If DC bus caution light illuminates, no reset of the bus fault reset switch should be attempted.
Probable Cause: Right TRU inoperative.
Immediate Action: Check R TRU circuit breaker on 115V AC VARIABLE FREQUENCY circuit breaker panel.
Remarks: If a double TRU failure occurs secondary DC buses tie to main DC buses.
Probable Cause: Main battery is isolated from main bus.
Immediate Action: Cycle MAIN BATT switch on DC CONTROL panel OFF then ON. If caution light remains on, turn MAIN BATT off.
Remarks: Main battery is removed from main bus automatically if a right main bus fault occurs or if external DC power is connected.
Probable Cause: Auxiliary battery is isolated from main bus.
Immediate Action: Cycle AUX BATT switch on DC CONTROL panel OFF then ON. If caution light remains on, turn AUX BATT off.
Remarks: Auxiliary battery is removed from main bus automatically if a left main bus fault occurs or if external DC power is connected.
Probable Cause: Number 1 DC generator has failed or is offline.
Immediate Action: A generator reset attempt may be made by selecting DC CONTROL GEN 1 switch off then on.
Remarks: Main DC buses automatically tie.
Probable Cause: Number 2 DC generator has failed or is offline.
Immediate Action: A generator reset attempt may be made by selecting DC CONTROL GEN 2 switch off then on.
Remarks: Main DC buses automatically tie.
Probable Cause: Number 1 AC generator has failed or is offline.
Immediate Action: A generator reset attempt may be made by selecting AC CONTROL GEN 1 switch off then on.
Remarks: Variable frequency buses automatically tie.
Probable Cause: Number 2 AC generator has failed or is offline.
Immediate Action: A generator reset attempt may be made by selecting AC CONTROL GEN 2 switch off then on.
Remarks: Variable frequency buses automatically tie.
Probable Cause: Main battery temperature exceeds 65ºC.
Immediate Action: Confirm battery overheat on temperature monitor. Select MAIN BATT switch OFF to isolate battery from charging system.
Remarks: None.
Probable Cause: Auxiliary battery temperature exceeds 65ºC.
Immediate Action: Confirm battery overheat on temperature monitor. Select AUX BATT switch OFF to isolate battery from charging system.
Remarks: None.
Probable Cause: Left transformer/rectifier unit overheated.
Immediate Action: Left TRU must be shut down by pulling L TRU circuit breaker on 115 V AC variable frequency panel.
Remarks: Left and right secondary buses automatically tie when the left TRU is shut down. Left TRU may be reenergized when it has cooled and caution light goes out.
Probable Cause: Right transformer/rectifier unit overheated.
Immediate Action: Right TRU must be shut down by pulling R TRU circuit breaker on 115 V AC variable frequency panel.
Remarks: Left and right secondary buses automatically tie when the left TRU is shut down. Right TRU may be reenergized when it has cooled and caution light goes out.
Probable Cause: Number 1 DC generator windings overheating.
Immediate Action: Shut down the number 1 DC generator.
Remarks: Caution light will go out when generator cools. Reselect generator and reduce DC electrical load.
Probable Cause: Number 2 DC generator windings overheating.
Immediate Action: Shut down the number 2 DC generator.
Remarks: Caution light will go out when generator cools. Reselect generator and reduce DC electrical load.
Probable Cause: Number 1 AC generator windings overheating.
Immediate Action: Shut down the number 1 AC generator.
Remarks: Caution light will go out when generator cools. Reselect generator and reduce AC electrical load.
Probable Cause: Number 2 AC generator windings overheating.
Immediate Action: Shut down the number 2 AC generator.
Remarks: Caution light will go out when generator cools. Reselect generator and reduce AC electrical load.
Probable Cause: Passenger entry door not properly secured.
Immediate Action: Secure door if aircraft on ground. If in flight and depressurization is necessary, see the QRH for inflight depressurization.
Remarks: Warn all personnel to remain clear of door. PASS DOOR caution light goes out when door is closed securely.
Probable Cause: Bag door not properly secured.
Immediate Action: Secure door if aircraft on ground. If in flight and depressurization is necessary, see the QRH for inflight depressurization.
Remarks: Warn all personnel to remain clear of door. BAG DOOR caution light goes out when door is closed securely.
Probable Cause: Engine fire detected or detector loop circuit malfunction.
Immediate Action: Check fire protection panel for illuminated PULL FUEL OFF handle and glareshield for flashing ENGINE FIRE light. If those indications are present proceed with the QRH engine fire procedure.
Remarks: If fire warnings are not present and a FAULT light is illuminated, select the appropriate loop arming selector to remaining detector loop.
Probable Cause: Smoke present in the baggage area.
Immediate Action: Have flight attendant investigate the cause of smoke and proceed with the QRH inflight fire procedure.
Remarks: SMOKE caution light remains illuminated as long as smoke is present in the baggage compartment.
Probable Cause: Number 1 or 2 rudder actuator pressure fails to decrease to 900 psi when the aircraft exceeds 140 knots.
Immediate Action: Reduced airspeed to 200 knots or below.
Remarks: The rudder pressure is incorrect for the current airspeed. Or a rudder actuator is operating with an abnormal pressure.
Probable Cause: Number 1 rudder actuator depressurized (pressure decreasing below 600 psi).
Immediate Action: Affected RUD 1 PUSH OFF switchlight - PUSH OFF.
Remarks: Number 2 rudder actuator operates at 3000 psi and RUD FULL PRESS caution light illuminates.
Probable Cause: Number 2 rudder actuator depressurized (pressure decreasing below 600 psi).
Immediate Action: Affected RUD 2 PUSH OFF switchlight - PUSH OFF.
Remarks: Number 1 rudder actuator operates at 3000 psi and RUD FULL PRESS caution light illuminates.
Probable Cause: The REFUEL or DEFUEL selection is made on the refuel/defuel panel.
Immediate Action: Refer to the “FUELING ON” caution in the QRH.
Remarks: The FUELING ON caution light will not trigger the master caution light flasher when illuminated. When the REFUEL or DEFUEL selection is made on the refuel/defuel panel, fuel transfer is not possible.
Probable Cause: Either the rudder actuator has depressurized causing 3000 psi to be applied to the remaining actuator.
Immediate Action: None.
Remarks: RUD PRESS caution light if remaining actuator illuminates if aircraft speed exceeds 140 knots.
Probable Cause: Main flap drive failure.
Immediate Action: None.
Remarks: Flaps will continue to operate using secondary transmission shaft. Flaps may be operated normally for remainder of flight.
Probable Cause: Loss of hydraulic pressure in flap power unit during flap extension or retraction.
Immediate Action: Check number 1 MAIN and STANDBY hydraulic pressure indicators and quantity indicators.
Remarks: Unless hydraulic power to flap drive is restored, flaps are immobilized at existing position.
Probable Cause: The left AOA vane heater has failed or de-energized.
Immediate Action: Refer to the #1 STALL SYST FAIL caution light in Ch. 13 of the QRH.
Remarks: The pilot’s EADI AOA speed indicator is biased out of view. This light is not applicable to the 100 series.
Probable Cause: The right AOA vane heater has failed or de-energized.
Immediate Action: Refer to the #2 STALL SYST FAIL caution light in Ch. 13 of the QRH.
Remarks: The copilot’s EADI AOA speed indicator is biased out of view. This light is not applicable to the 100 series.
Probable Cause: Left lift transducer or lift computer failed or de-energized.
Immediate Action: Check stall warning switch at STALL WARNING position. Check left DC circuit breaker panel STALL WRN HTR (S7) and right DC circuit breakers STALL FAIL MIN (R7).
Remarks: This light does not apply to the Model 311.
Probable Cause: Right lift transducer or lift computer failed or de-energized.
Immediate Action: Check stall warning switch at STALL WARNING position. Check right DC circuit breaker panel STALL WRN HTR (S7) and left DC circuit breakers STALL FAIL MIN (R7).
Remarks: This light does not apply to the Model 311.
Probable Cause: No. 1 engine boost ejector pump failed (output below 5.5 psi).
Immediate Action: Select TANK 1 AUX PUMP on.
Remarks: Caution light should go out as fuel boost pressure increases to 7.5 psi.
Probable Cause: No. 2 engine boost ejector pump failed (output below 5.5 psi).
Immediate Action: Select TANK 2 AUX PUMP on.
Remarks: Caution light should go out as fuel boost pressure increases to 7.5 psi.
Probable Cause: No. 1 fuel tank quantity less than 130 lbs.
Immediate Action: Transfer fuel from other tank or land as soon as practical to refuel.
Remarks: None.
Probable Cause: No. 2 fuel tank quantity less than 130 lbs.
Immediate Action: Transfer fuel from other tank or land as soon as practical to refuel.
Remarks: None.
Probable Cause: Fuel filter restricted or blocked.
Immediate Action: None.
Remarks: Fuel bypasses filter to supply engine. Report condition on landing.
Probable Cause: Fuel filter restricted or blocked.
Immediate Action: None.
Remarks: Fuel bypasses filter to supply engine. Report condition on landing.
Probable Cause: No. 1 hydraulic system fluid exceeds 109ºC.
Immediate Action: If condition exists on ground because of high ambient temperatures, operate flight controls actuated by the No. 1 hydraulic system (wing flaps inboard roll spoilers, rudder, brakes) to circulate fluid. If condition exists in flight probable cause is failed pressure regulator; land as soon as practical for repairs.
Remarks: Caution light goes out when fluid cools to 95ºC.
Probable Cause: No. 2 hydraulic system fluid exceeds 109ºC.
Immediate Action: If condition exists on ground because of high ambient temperatures, operate flight controls actuated by the No. 2 hydraulic system (parking brake, nosewheel steering, rudder, ground spoilers, outboard roll spoilers) to circulate fluid. If condition exists in flight probable cause is failed pressure regulator; land as soon as practical for repairs.
Remarks: Caution light goes out when fluid cools to 95ºC.
Probable Cause: No 1. standby hydraulic pump electric motor temperature exceeds 170ºC.
Immediate Action: If condition occurs when main hydraulic system is inoperative, select No. 1 standby hydraulic pump to NORM if flight condition permit loss of No. 1 hydraulic services. Avoid selection of wing flaps. If condition occurs with main system inoperative and wing flaps extended, raise wing flaps as soon as possible and select STBY HYD PRESS switch to NORM.
Remarks: When pump motor cools to 160ºC caution light will go out and pump may be selected on if needed.
Probable Cause: No 2. standby hydraulic pump electric motor temperature exceeds 170ºC.
Immediate Action: If condition occurs when main hydraulic system is inoperative, select No. 2 standby hydraulic pump to NORM if flight condition permit loss of No. 2 hydraulic services. Avoid selection of wing flaps. If condition occurs with main system inoperative and wing flaps extended, raise wing flaps as soon as possible and select STBY HYD PRESS switch to NORM.
Remarks: When pump motor cools to 160ºC caution light will go out and pump may be selected on if needed.
Probable Cause: No 1. engine driven hydraulic pump failed (pressure below 2000 psi).
Immediate Action: Select STBY HYD PRESS 1 switch to on.
Remarks: Caution light will remain on the standby hydraulic pump pressure will be displayed on No. 1 STANDBY and MAIN hydraulic pressure indicators.
Probable Cause: No 2. engine driven hydraulic pump failed (pressure below 2000 psi).
Immediate Action: Select STBY HYD PRESS 2 switch to on.
Remarks: Caution light will remain on the standby hydraulic pump pressure will be displayed on No. 2 STANDBY and MAIN hydraulic pressure indicators.
Probable Cause: No 1. pitot heater selected OFF with DC electrical system energized.
Immediate Action: Select PITOT STATIC 1 switch on.
Remarks: None.
Probable Cause: No 2. pitot heater selected OFF with DC electrical system energized.
Immediate Action: Select PITOT STATIC 2 switch on.
Remarks: None.
Probable Cause: Elevator horn heater failure. Light will flash momentarily on when heaters are first selected.
Immediate Action: Check ELEV HORN HT 1 (N7) circuit breaker on left DC circuit breaker panel and ELEV HORN HT 1 and ELEV HORN HT 2 circuit breaker on 115 v AC VARIABLE FREQUENCY circuit breaker panel.
Remarks: None.
Probable Cause: Left windshield overheated. Normal temperature sensor or normal temperature control circuits in right window controller inoperative.
Immediate Action: Operate windshield heat at WARM-UP. Caution light should go out as windshield cools.
Remarks: If necessary, windshield heat may be selected to NORMAL for short intervals to maintain clear vision. OR L W/SHLD HT circuit breaker could be pulled to de-energize left windshield and allow normal operation of right windshield and pilot’s side window by selecting windshield heat to NORMAL and selection of PLT WDO/HT switch to ON.
Probable Cause: Right windshield overheated. Normal temperature sensor or normal temperature control circuits in right window controller inoperative.
Immediate Action: Operate windshield heat at WARM-UP. Caution light should go out as windshield cools.
Remarks: If necessary, windshield heat may be selected to NORMAL for short intervals to maintain clear vision. OR R W/SHLD HT circuit breaker could be pulled to de-energize left windshield and allow normal operation of left windshield and pilot’s side window by selecting windshield heat to NORMAL and selection of PLT WDO/HT switch to ON.
Probable Cause: Pilot’s side window overheated. Temperature sensor or temperature control circuits in side window controller inoperative.
Immediate Action: Select PLT WDO/HT switch to OFF. Caution light should go out as window cools.
Remarks: Select PLT WDO/HT switch to ON if side WDO HOT caution light goes out.
Probable Cause: Airframe deice system pressure insufficient for deicer boot operation (fallen below 5.5 psi).
Immediate Action: Airframe auto selector - OFF. Select BOOT air switch to ISO. Manually select inner and outer tailplane boots and engine intake boot on operative side.
Remarks: Exit icing conditions if possible.
Probable Cause: Nosewheel steering ECU malfunction. Or nose wheels have turned beyond 60º and activated the limit switch.
Immediate Action: Center steering handle and nosewheel. Select nosewheel steering to OFF.
Remarks: None.
Probable Cause: Emergency/parking brake is on.
Immediate Action: None.
Remarks: Caution light goes out when EMERG BRAKE lever is released.
Probable Cause: Outboard or inboard anti-skid control unit failed.
Immediate Action: Check anti-skid switch - ON. Check right DC circuit breaker panel ANTISKID INBD (Q6) and OUTBOARD (R6) circuit breakers.
Remarks: Anti-skid control will be reduced by 50%. Also illuminates during anti-skid test.
Probable Cause: Landing gear door sequence valve relay failed with aircraft airborne and gear up.
Immediate Action: DO NOT attempt to lower gear by normal selection. Use landing gear alternate procedure in Flight Manual to extend gear.
Remarks: Landing gear door of the corresponding failed relay will not open before gear extends if normal extension is selected, resulting in structural damage.
Probable Cause: Fault in a weight on wheels sensing circuit within PSEU.
Immediate Action: Flight may be completed, but rectification must be carried out before the next flight, even though the caution light goes out on touch down.
Remarks: Landing gear may not retract. Systems depending on weight on wheels sensing circuits will remain operational because of redundancy of the weight on wheels sensors.
Probable Cause: Emergency lights not armed with DC electrical system energized.
Immediate Action: Select pilot’s EMER LIGHTS switch to arm.
Remarks: None.
Probable Cause: No. 1 bleed air supply duct exceeds 287ºC.
Immediate Action: If light repeatedly illuminates and goes out, select No. 1 BLEED switch off or reduce bleed flow control setting as much as inflow requirements allow.
Remarks: Normal operation is automatically interrupted and bleed air is shut off until supply duct cools. Caution light goes out and normal operation resumes when supply duct cools.
Probable Cause: No. 2 bleed air supply duct exceeds 287ºC.
Immediate Action: If light repeatedly illuminates and goes out, select No. 2 BLEED switch off or reduce bleed flow control setting as much as inflow requirements allow.
Remarks: Normal operation is automatically interrupted and bleed air is shut off until supply duct cools. Caution light goes out and normal operation resumes when supply duct cools.
Probable Cause: No 1. engine oil pressure below 42 +/- 3 psi [Model 103/106] (42 +/- 2 psi [Model 311]).
Immediate Action: Check oil pressure indicator. If low oil pressure is confirmed shut engine down.
Remarks: None.
Probable Cause: No 2. engine oil pressure below 42 +/- 3 psi [Model 103/106] (42 +/- 2 psi [Model 311]).
Immediate Action: Check oil pressure indicator. If low oil pressure is confirmed shut engine down.
Remarks: None.
Probable Cause: No 1. engine electronic control unit failed or deactivated by MANUAL selection on ENG 1 ECU MODE switchlight.
Immediate Action: Select ENG 1 ECU MODE selector ON. Check left DC circuit breaker panel ECU ENG 1 circuit breaker (K4) and right DC circuit breaker panel ECU ENG 1 circuit breaker (J7).
Remarks: If ECU fault is not cleared power lever increase in Model 103/106 (decrease in Model 311) will be required to keep engine torque symmetric.
Probable Cause: No 2. engine electronic control unit failed or deactivated by MANUAL selection on ENG 2 ECU MODE switchlight.
Immediate Action: Select ENG 2 ECU MODE selector ON. Check left DC circuit breaker panel ECU ENG 2 circuit breaker (H3) and right DC circuit breaker panel ECU ENG 1 circuit breaker (M8).
Remarks: If ECU fault is not cleared power lever increase in Model 103/106 (decrease in Model 311) will be required to keep engine torque symmetric.
Probable Cause: Flight data recorder failed or de-energized.
Immediate Action: Check the avionics circuit breaker panel FDR (A9) circuit breaker and left DC circuit breaker panel FDAU and FDR STAT circuit breakers (G2, H2). Check anti-collision lights switch selected to RED or WHITE if aircraft on ground.
Remarks: Flight data recorder is energized when aircraft is airborne or when on ground with anti-collision lights on.
Probable Cause: Ground proximity warning system computer failure or de-energized.
Immediate Action: Check avionics circuit breaker panel GPWS (B9 and B3) circuit breakers.
Remarks: None.
Probable Cause: An inboard roll spoiler lift dump valve failed.
Immediate Action: None.
Remarks: If illumination occurs in flight, one of the inboard lift dump valves has failed open. Inboard roll spoilers will remain in flight mode and will deploy normally in ground mode at touchdown. If illumination occurs at touchdown one of the lift dump valves has failed closed and the inboard roll spoilers will not deploy in ground mode. This light does not apply to the Model 311.
Probable Cause: An outboard roll spoiler lift dump valve failed.
Immediate Action: None.
Remarks: If illumination occurs in flight, one of the outboard lift dump valves has failed open. Outboard roll spoilers will remain in flight mode and will deploy normally in ground mode at touchdown. If illumination occurs at touchdown one of the lift dump valves has failed closed and the outboard roll spoilers will not deploy in ground mode. This light does not apply to the Model 311.
Probable Cause: Ground spoiler lift dump valve has closed.
Immediate Action: None.
Remarks: If illumination occurs in flight, one of the lift dump valves has failed open. The ground spoilers will still operate normally and deploy on touchdown. If illumination occurs at touchdown one of the lift dump valves has failed closed and the ground spoilers will not deploy. This light does not apply to the Model 311.
Probable Cause: Indicates that the #1 or #2 rudder isolation valve has closed.
Immediate Action: Refer to #1 HYD ISO VLV or #2 HYD ISO VLV checklist in Ch. 12 of the QRH.
Remarks: Once hydraulic quantity in either hydraulic reservoir drops to approximately 0.68 quarts, the rudder isolation valve will close. The caution light will illuminate, and the only hydraulic service available from that system will be the rudder.
