Beechcraft Baron 58 - Stall Warning

BEECHCRAFT Baron 58
Serial TH 773 and After
STAll WARNING
Section VII
Systems Description
A stall warning horn on the cabin forward bulkhead sounds
a warning signal while there is time for the pilot to correct
the attitude. The horn is triggered by a sensing vane on the
leading edge of the left wing and is effective in all flight
attitudes and at all weights and airspeeds. Irregular and
intermittent at first, the warning signal will become steady
as
the airplane approaches a complete stall.
Electrical power is supplied to the stall warning horn directly
from the
battery (TH-733 through TH-972) or from the main
electrical bus
(TH-973 and after).
WARNING
The stall warning horn (TH-973 and after) is
inoperative when the battery and alternator
switches are
OFF while in flight.
In icing conditions, stalling airspeeds should be expected to
increase due to the
distortion of the wing airfoil when ice
has
accumulated on the airplane. For the same reason, stall
warning devices tend to lose their accuracy. The sensing
vane is installed on a plate that can be electrically heated,
preventing ice from forming on the vane of the transducer.
A switch on the pilot's subpanel, placarded PITOT HEAT,
supplies
power to the heated pitot mast and to the heating
plate at the stall warning transducer. However, any ac-
cumulation of ice in the proximity of the stall warning vane
reduces
the probability of accuracy in the stall warning sys-
tem
whether or not the vane itself is clear of ice. For this
reason, it is advisable to maintain an extra margin of air-
speed above the stall speed.
September, 1979
7-39