Emergency Operation In Clouds (Vacuum System Failure); Executing A 180° Turn In Clouds; Emergency Descent Through Clouds - Cessna 152 1979 Pilot Operating Handbook

CESSNA
MODEL 152
EMERGENCY OPERATION IN CLOUDS
(Vacuum System Failure)
In the event of a vacuum system failure during flight, the directional indicator and attitude
indicator will be disabled, and the pilot will have to rely on the turn coordinator if he
inadvertently flies into clouds. The following instructions assume that only the electrically-
powered turn coordinator is operative, and that the pilot is not completely proficient in
instrument flying.
EXECUTING A 180° TURN IN CLOUDS
Upon inadvertently entering the clouds, an immediate plan should be made to turn back as
follows:
1. Note the compass heading.
2. Note the time of the minute hand and observe the position of the sweep second hand on
the clock.
3. When the sweep second hand indicates the nearest half-minute, initiate a standard rate left
turn, holding the turn coordinator symbolic airplane wing opposite the lower left index mark
for 60 seconds. Then roll back to level flight by leveling the miniature airplane.
4. Check accuracy of the turn by observing the compass heading which should be the
reciprocal of the original heading.
5. If necessary, adjust heading primarily with skidding motions rather than rolling motions so
that the compass will read more accurately.
6. Maintain altitude and airspeed by cautious application of elevator control.
overcontrolling by keeping the hands off the control wheel as much as possible and
steering only with rudder.

EMERGENCY DESCENT THROUGH CLOUDS

If conditions preclude reestablishment of VFR flight by a 180° turn, a descent through a cloud
deck to VFR conditions may be appropriate.
emergency descent through clouds. To guard against a spiral dive, choose an easterly or
westerly heading to minimize compass card swings due to changing bank angles. In addition,
keep hands off the control wheel and steer a straight course with rudder control by monitoring
the turn coordinator. Occasionally check the compass heading and make minor corrections to
hold an approximate course. Before descending into the clouds, set up a stabilized let-down
condition as follows:
1 July 1978
EMERGENCY PROCEDURES
If possible, obtain radio clearance for an
SECTION 3
Avoid
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