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Document No.:G304C/AFM
Date of Issue: 12/01
4-10
Approved
H
P
H
Ltd.
During extreme turbulence, as it may occur for instance in wave
rotors, thunderclouds, visible up-currents (stubble fire), or while
crossing mountain ranges, the maximum speed in rough air V
RA
200 km/h (108 KIAS, 124mph) should not be exceeded. The
necessary control column travel is relatively small from the stalling
speed to the maximum speed, in particular at rear C.G. positions,
however any speed change will be noticed by a change of the
control forces.
The air brakes can be open up to V
NE
= 250 km/h (135 KIAS, 155
mph), however this should only be done in an emergency or when
unintentionally exceeding the maximum permissible speeds shown
in 2.2, which is indicated by a sudden deceleration.
For this reason, ensure that your harness is tight, and that you do
not unintentionally move or jolt the control column while operating
the air brake lever. Loose objects in the cockpit should be avoided,
as well.
4.5.6 Slow speed flight – stall characteristics
For familiarization with
Glasflügel 304 C
sailplane, we recommend
to perform stalling tests from a straight and level flight, and from a
turn of 45° bank.
The tests should be done of course at a safe altitude.
Refer to Section 5. par. 5.2.2 for the sailplane stalling speeds.
With closed air brakes, a stall warning occurs as a light buffeting
and vibration and oscillation of the ASI needle towards the stalling
speed. If the air brakes are extended, the airframe vibrates
noticeably at approx. 5km/h (2 kts, 3mph) above the stalling speed.
If the control column is slowly pulled back, a stall occurs, which is
evidenced by a downward pitching motion or rolling motion.
The back pressure on the control column should then be
immediately released. If the air brakes are extended, the loss of
altitude after wing drop is approx. 50m (150 ft).
With medium and forward C.G. positions you can produce and
correct roll and yaw during stall. This is shown itself by "spongy"
controls, increasing of the sinking speed and oscillation of the ASI
needle.
