MODE 3: Negative climb rate or altitude loss after take-off
Negative Climb Rate or Altitude Loss After Take-Off is active for take-off and go-around
below 1347 feet AGL when flaps are in other than landing position.
NOTE: Mode 3 and Mode 4 cannot be active at the same time.
TAWS uses radio and barometric altitude loss to provide this warning. The “DON’T SINK”
aural alert is generated and the TERR caution annunciator is illuminated if sufficient altitude
is lost after take-off or go-around to enter the DON’T SINK envelope. The alert is reset when
a positive rate of climb is greater than 500 FPM or if the initial decent altitude is reached with
a positive rate of climb less than 500 FPM.
Should it be necessary to land while Mode 3 is active (just after take-off or a go-around and
the aircraft has not reached 1347 feet AGL), the Mode 3 aural alert “DON’T SINK” will occur
until flaps are selected to landing position. This does not activate Mode 4, but it cancels the
aural alert.
There are four ways to set the envelope:
• Transition WOW from ground to air.
• While radio altimeter is less than 1347 feet AGL
• Cycle landing gear from down to up.
• Have a climb rate of greater than 300 fpm when radio altimeter is less than 245 feet AGL.
Fokker 50 - Flight Navigation Instruments
To Next Page