An emergency
descent is a maneuver for descending as rapidly
as possible to a lower altitude or to the ground
for an emergency landing.
The need for this maneuver may result from an
uncontrollable fire, a sudden loss of cabin
pressurization, or any other situation demanding
an immediate and rapid descent. The objective
is to descend the airplane as soon and as rapidly
as possible within the structural limitations
of the airplane.
Simulated emergency descents should be made
in a turn to check for other air traffic below
and to look around for a possible emergency
landing area.
A radio call announcing descent intentions may
be appropriate to alert other aircraft in the
area.
When initiating the descent, a bank of approximately
30 to 45° should be established to maintain
positive load factors (G forces) on the airplane.
Emergency descent training should be performed
as recommended by the manufacturer, including
the configuration and airspeeds.
Power should be reduced to idle.
The flaps should be extended as recommended
by the manufacturer. This provides maximum
drag so the descent can be made as rapidly
as possible, without excessive airspeed, which
should pass the never exceed speed, or maximum
flap extended speed. If the descent is conducted
in turbulent conditions, the pilot must also
comply with maneuvering speed limitations.
In the case of an engine fire a high speed
high airspeed descent could blow out the fire.
However, the weakening of the airplane structure
is a major concern and descent at lower speed
places less stress on the airplane.
The descent should be a made at the maximum
allowable airspeed consistent with the procedure
used. This provides increased drag and therefore
the loss of altitude as quickly as possible.
Banking and turning the airplane is important.
You will descend faster and be able to clear
the area below you.
The recovery from an emergency descentshould
be initiated at a high enough altitude to
ensure a safe recovery back to level flight
or a precautionary landing.
When the descent is established and stabilized
during training, the descent should be terminated.
In airplanes with piston engines, prolonged
practice of emergency descents should be avoided
to prevent excessive cooling of the engine
cylinders.
