b737-300/400 warning systems

of 16PT. METRO BATAVIAPT. METRO BATAVIADirectorate of OperationalDirectorate of Operational

737-300/400737-300/400WARNING SYSTEMSWARNING SYSTEMS

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Instrument PanelsInstrument Panels

Master Caution SystemMaster Caution System



MASTER CAUTION lights:MASTER CAUTION lights:Illuminated –Illuminated –A system annunciator light has illuminated on the A system annunciator light has illuminated on the system annunciator panel. Master caution lights system annunciator panel. Master caution lights remain illuminated as long as the fault condition remain illuminated as long as the fault condition exists or until the crew resets the master caution exists or until the crew resets the master caution system.system.

Push –Push –• Extinguishes both MASTER CAUTION lights.Extinguishes both MASTER CAUTION lights.• System annunciator light(s) on system System annunciator light(s) on system annunciator panel extinguish.annunciator panel extinguish.• Resets master caution system for additional Resets master caution system for additional

master caution warnings.master caution warnings.

Left SideLeft Side

Right SideRight Side


Left SideLeft Side



System Annunciator Panels:System Annunciator Panels:Illuminated –Illuminated –An amber light (related to the illuminated system An amber light (related to the illuminated system annunciator), has illuminated on the forward annunciator), has illuminated on the forward overhead panel, aft overhead panel, or overhead panel, aft overhead panel, or overheat/fire protection panel.overheat/fire protection panel.

To extinguish the system annunciator light(s), To extinguish the system annunciator light(s), push either MASTER CAUTION light. push either MASTER CAUTION light.

To recall the system annunciator light(s), push To recall the system annunciator light(s), push and release either system annunciator panel. and release either system annunciator panel. This action will re-illuminate the MASTER This action will re-illuminate the MASTER CAUTION lights and the related system CAUTION lights and the related system annunciator(s) if the fault condition still exists.annunciator(s) if the fault condition still exists.

Note: The system annunciator panels are also Note: The system annunciator panels are also known as “recall” panels.known as “recall” panels.



System Annunciator Panels:System Annunciator Panels:A single fault in certain redundant systems A single fault in certain redundant systems do notdo not illuminate the MASTER CAUTION or associated illuminate the MASTER CAUTION or associated system annunciator light. These faults, however, system annunciator light. These faults, however, are stored in the master caution system. Pushing are stored in the master caution system. Pushing either system annunciator panel recalls the single either system annunciator panel recalls the single fault, which results in the illumination of the fault, which results in the illumination of the MASTER CAUTION and associated system MASTER CAUTION and associated system annunciator light. To reset the system, simply annunciator light. To reset the system, simply push either MASTER CAUTION light.push either MASTER CAUTION light.

Examples of single faults are: MACH TRIM FAIL, Examples of single faults are: MACH TRIM FAIL, SPEED TRIM FAIL, AUTOSLAT FAIL, and one SPEED TRIM FAIL, AUTOSLAT FAIL, and one LOW PRESSURE light illuminated in a main fuel LOW PRESSURE light illuminated in a main fuel tank. Please see the Flight Controls presentation tank. Please see the Flight Controls presentation or Fuel presentation for additional information.or Fuel presentation for additional information.

Left SideLeft Side




This chart indicates which amber fault lights areThis chart indicates which amber fault lights areassociated with the above system annunciator lights.associated with the above system annunciator lights.

OVHT/DET:OVHT/DET:ENG 1 OVERHEATENG 1 OVERHEATENG 2 OVERHEATENG 2 OVERHEATAPU DET INOPAPU DET INOP

FUEL:FUEL:LOW PRESSURELOW PRESSUREFILTER BYPASSFILTER BYPASS

APU:APU:LOW PRESSURELOW PRESSUREHIGH OIL TEMP/FAULTHIGH OIL TEMP/FAULTOVERSPEEDOVERSPEED

IRS:IRS:FAULTFAULTON DCON DCDC FAILDC FAIL

ELEC:ELEC:LOW OIL PRESSURELOW OIL PRESSUREHIGH OIL TEMPHIGH OIL TEMPSTANDBY PWR OFFSTANDBY PWR OFFTRANSFER BUS OFFTRANSFER BUS OFFBUS OFFBUS OFF

FLT CONT:FLT CONT:LOW QUANTITYLOW QUANTITYLOW PRESSURELOW PRESSUREFEEL DIFF PRESSFEEL DIFF PRESSSPEED TRIM FAILSPEED TRIM FAILMACH TRIM FAILMACH TRIM FAILAUTO SLAT FAILAUTO SLAT FAILYAW DAMPERYAW DAMPER

Left side annunciatorsLeft side annunciators



AIR COND:AIR COND:DUCT OVERHEATDUCT OVERHEATDUAL BLEEDDUAL BLEEDPACK TRIP OFFPACK TRIP OFFWING-BODY OVERHEATWING-BODY OVERHEATBLEED TRIP OFFBLEED TRIP OFFAUTO FAILAUTO FAILOFF SCHED DESCENTOFF SCHED DESCENT

DOORS:DOORS:FWD/AFT ENTRYFWD/AFT ENTRYFWD/AFT SERVICEFWD/AFT SERVICEFWD/AFT CARGOFWD/AFT CARGOEQUIPEQUIPAIRSTAIRAIRSTAIRTIRE SCREENTIRE SCREEN

OVERHEAD:OVERHEAD:OFF OFF (EQUIP COOLING)(EQUIP COOLING)NOT ARMED NOT ARMED (EMER EXIT LIGHTS)(EMER EXIT LIGHTS)OFFOFF (FLIGHT RECORDER) (FLIGHT RECORDER)PASS OXY ONPASS OXY ON

HYD:HYD:OVERHEATOVERHEATLOW PRESSURELOW PRESSURE

ENG:ENG:REVERSERREVERSERINOP (PMC)INOP (PMC)LOW IDLELOW IDLE

ANTI-ICE:ANTI-ICE:COWL ANTI-ICECOWL ANTI-ICEOVERHEAT OVERHEAT (windows)(windows)PITOT HEAT PITOT HEAT (any (any amber light on amber light on PITOT STATIC panel)PITOT STATIC panel)

Right side annunciatorsRight side annunciators

1111

11 AS INSTALLEDAS INSTALLED This chart indicates which amber fault lights areThis chart indicates which amber fault lights areassociated with the above system annunciator lights.associated with the above system annunciator lights.


Fire Warning SystemFire Warning SystemFIRE WARN lights:FIRE WARN lights:Illuminated –Illuminated –• Indicates a fire warning in the engine(s), main Indicates a fire warning in the engine(s), main

gear wheel well, or APU. Lights remain gear wheel well, or APU. Lights remain illuminated as long as the fire condition exists or illuminated as long as the fire condition exists or

until the crew resets the fire warning system.until the crew resets the fire warning system.• A fire system test is being performed.A fire system test is being performed.• Fire warning bell sounds.Fire warning bell sounds.• Remote APU fire warning horn sounds during an Remote APU fire warning horn sounds during an

APU fire if the aircraft is on the ground.APU fire if the aircraft is on the ground.

Push –Push –• Extinguishes both FIRE WARN lights.Extinguishes both FIRE WARN lights.• Silences fire warning bell.Silences fire warning bell.• Silences remote APU fire warning horn Silences remote APU fire warning horn (ground only).(ground only).• Resets fire warning system for additional fire Resets fire warning system for additional fire

warnings.warnings.

Note: Pushing the BELL CUTOUT switch on the Note: Pushing the BELL CUTOUT switch on the overheat/fire protection panel results in the same overheat/fire protection panel results in the same four items listed above.four items listed above.

Left SideLeft Side


Listen to theListen to thefire warning bellfire warning bell

Listen to the APUListen to the APUfire warning hornfire warning horn


Mach/Airspeed WarningMach/Airspeed Warning


Mach/Airspeed WarningMach/Airspeed Warning

MACH AIRSPEED WARNING TEST Switches:MACH AIRSPEED WARNING TEST Switches:Push –Push –• Tests the No. 1 or No. 2 Mach/airspeed warning Tests the No. 1 or No. 2 Mach/airspeed warning

system. system. • Clacker soundsClacker sounds

Two independent Mach/airspeed warning Two independent Mach/airspeed warning systems provide a distinct aural warning (clacker) systems provide a distinct aural warning (clacker) any time the maximum operating airspeed of any time the maximum operating airspeed of VVmomo/M/Mmomo is exceeded. The clacker may only be is exceeded. The clacker may only be silenced by reducing airspeed below Vsilenced by reducing airspeed below Vmomo/M/Mmomo. .

Listen to the clackerListen to the clacker


Stall WarningStall Warning


Stall WarningStall Warning

STALL WARNING TEST Switches:STALL WARNING TEST Switches:Push –Push –• Tests the No. 1 or No. 2 stall management Tests the No. 1 or No. 2 stall management

computer by “shaking” each control column.computer by “shaking” each control column.• No. 1 stall management computer “shakes” No. 1 stall management computer “shakes”

Captain’s control column. No. 2 stall Captain’s control column. No. 2 stall management computer “shakes” First Officer’s management computer “shakes” First Officer’s

control column.control column.• Either stick shaker vibrates both columns Either stick shaker vibrates both columns

through column interconnects.through column interconnects.• Test vibrations are inhibited while airborne.Test vibrations are inhibited while airborne.• Test can only be done while on the ground with Test can only be done while on the ground with

AC power on the aircraft.AC power on the aircraft.

The stall warning “stick shaker” consists of two The stall warning “stick shaker” consists of two eccentric weight motors, one one each control eccentric weight motors, one one each control column. They are designed to warn the pilots column. They are designed to warn the pilots before a stall develops. The system is armed in before a stall develops. The system is armed in flight at all times.flight at all times.

Listen to theListen to thestick shakerstick shaker

See picture of See picture of stick shaker motorstick shaker motor


Landing Gear Configuration WarningLanding Gear Configuration Warning

Control StandControl Stand



A steady warning horn is provided to alert the A steady warning horn is provided to alert the pilots whenever the aircraft is in a landing gear pilots whenever the aircraft is in a landing gear configuration and any gear is not down and configuration and any gear is not down and locked. The warning system monitors the locked. The warning system monitors the position of the landing gear, forward thrust position of the landing gear, forward thrust levers, and trailing edge flaps to determine if the levers, and trailing edge flaps to determine if the horn requires activation. Depending on the horn requires activation. Depending on the position of the aforementioned items, the HORN position of the aforementioned items, the HORN CUTOUT switch may or may not silence the CUTOUT switch may or may not silence the warning horn. The warning horn may also be warning horn. The warning horn may also be silenced by simply correcting the configuration silenced by simply correcting the configuration error; e.g. extending the landing gear.error; e.g. extending the landing gear.

Listen to the landingListen to the landinggear configurationgear configuration

warning hornwarning horn



HORN CUTOUT Switch:HORN CUTOUT Switch:Push (trailing edge flaps 1 through 10 units) –Push (trailing edge flaps 1 through 10 units) –Will silence the warning horn if either or both Will silence the warning horn if either or both forward thrust levers are between idle and forward thrust levers are between idle and approximately 10approximately 10° of thrust lever angle.° of thrust lever angle.

Push (trailing edge flaps at 15 units) –Push (trailing edge flaps at 15 units) –• Will silence the warning horn if either forward Will silence the warning horn if either forward

thrust lever is between idle and approximately thrust lever is between idle and approximately 1010° of thrust lever angle ° of thrust lever angle andand the opposite the opposite forward thrust lever is greater than forward thrust lever is greater than

approximately approximately 3030° of thrust lever angle.° of thrust lever angle.• Will Will NOTNOT silence the warning horn if both silence the warning horn if both forward thrust levers are below approximately forward thrust levers are below approximately

3300° of thrust lever angle.° of thrust lever angle.

Push (trailing edge flaps greater than 15 units) –Push (trailing edge flaps greater than 15 units) –The warning horn The warning horn cannotcannot be silenced regardless be silenced regardless of forward thrust lever position.of forward thrust lever position.


Takeoff Configuration WarningTakeoff Configuration Warning

Listen to the takeoffListen to the takeoffconfigurationconfigurationwarning hornwarning horn

The takeoff configuration warning system is armed when the aircraft is on the ground and either or The takeoff configuration warning system is armed when the aircraft is on the ground and either or both forward thrust levers are advanced for takeoff. When advancing the forward thrust levers for both forward thrust levers are advanced for takeoff. When advancing the forward thrust levers for takeoff, an intermittent warning horn will sound if any of the following five conditions are not met:takeoff, an intermittent warning horn will sound if any of the following five conditions are not met:

1) Trailing edge flaps must be in the takeoff position (1, 2, 5, 10, or 15).1) Trailing edge flaps must be in the takeoff position (1, 2, 5, 10, or 15).2) Leading edge Krueger flaps must be in the takeoff position (fully extended).2) Leading edge Krueger flaps must be in the takeoff position (fully extended).3) The SPEED BRAKE handle must be in the DOWN position.3) The SPEED BRAKE handle must be in the DOWN position.4) Stabilizer trim must be within the stabilizer trim green band range.4) Stabilizer trim must be within the stabilizer trim green band range.5) Parking brake must not be set.5) Parking brake must not be set.

The takeoff configuration warning horn is cancelled when the configuration error is corrected.The takeoff configuration warning horn is cancelled when the configuration error is corrected.

11

11 AS INSTALLEDAS INSTALLED

Note: The sound of the takeoff configuration warning horn is the same sound as the cabin altitude Note: The sound of the takeoff configuration warning horn is the same sound as the cabin altitude warning horn.warning horn.

b737-300/400 warning systems

Engineering