Warning Systems - Warning System

General

The Warning System consists of two flight deck warning speakers, two master WARNING lights and two stick shaker motors, controlled by a Warnings Electronics Unit.

Warning Panel The warning system controls and activates visual and/or aural alerts for these warnings:

The warning system also provides:

Takeoff Configuration Warnings

CONFIG Warnings

Takeoff configuration warnings are armed when the airplane is on the ground and thrust is in the takeoff range (greater than 66.7% N1) on either engine. Takeoff configuration warnings consist of:

Takeoff configuration warning messages include:

All takeoff configuration-warning indications are:

When a takeoff configuration warning occurs, pushing either master warning/caution reset switch resets the master WARNING lights but does not silence the siren or clear the EICAS alert message. Before reaching rotation, the siren can be silenced and the EICAS alert message cleared only by retarding both Thrust Levers or correcting the condition. If thrust is reduced, the EICAS takeoff configuration message remains displayed for 10 seconds so the pilots can positively identify the configuration problem.

Holding the Configuration Test Switch in the T/O (Takeoff) position simulates accelerating an engine to takeoff power. No warnings occur when testing an airplane properly configured for takeoff. If the airplane is not configured for takeoff a configuration warning results. Releasing the test switch cancels the test.

Landing Configuration Warning

The landing configuration warning system alerts the crew that the Landing Gear is not extended for landing. The landing configuration warning activates if:

The landing configuration warning consists of:

With the Flap Lever in a landing position, the siren and alert message cannot be deactivated with the master warning/caution reset switches. The siren and message continue until the condition is corrected or the Gear Override switch is pushed.

If the warning is due to an Idle Thrust setting at low altitude, pushing either master warning/caution reset switch silences the siren and extinguishes the master WARNING lights. The EICAS message remains displayed until the configuration error is corrected.

Holding the Configuration Test Switch in the LDG (Landing) position results in a configuration warning regardless of landing gear position. All warning indications disappear when the switch is released.

Stall Warning

Stall Warning system

Warning of an impending stall is provided by two, independent stall warning systems controlling left and right stick shakers, which independently vibrate the left and right control columns sound clip.

Both systems are energized in flight and deactivated on the ground through air/ground logic.

Autoslats

If the Leading Edges Slats are in the takeoff position and the Left Hydraulic System is pressurized, a stall warning also causes the slats to extend to the landing position. The flap lever does not move. The slats automatically retract back to the takeoff position after the stall warning no longer exists.

Both systems are energized in flight and deactivated on the ground through Air/Ground Logic.

Holding either the L or R stall warning test switch:

If both the systems are tested at the same time, both columns vibrate.

Tail Strike Indication (757-300)

Tailstrike Sensor

The Tail Strike Indication System detects ground contact which could damage the airplane pressure hull. The system is installed in the aft body of the airplane. When activated the EICAS caution message TAIL STRIKE is displayed.

Overspeed Warning

OVERSPEED warning

An overspeed warning occurs if VMO/MMO limits are exceeded. The overspeed warning consists of:

All warning indications remain activated until airspeed is reduced below Vmo/Mmo.

The aural warning can be silenced by pushing either master warning/caution reset switch.

Altitude Alert