Honeywell Primus 880 Pilot's Manual page 145

PRIMUSr 880 Digital Weather Radar System
If you cannot avoid penetrating a thunderstorm, the following are some
do' s BEFORE entering the storm.
Tighten your safety belt, put on your shoulder harness if you have
D
one, and secure all loose objects.
Plan and hold your course to take you through the storm in a
D
minimum time.
To avoid the most critical icing, establish a penetration altitude below
D
the freezing level or above the level of - 15 _C.
Verify that pitot heat is on and turn on carburetor heat or jet engine
D
anti- ice. Icing can be rapid at any altitude and cause almost
instantaneous power failure and/or loss of airspeed indication.
Establish power settings for turbulence penetration airspeed
D
recommended in your aircraft manual.
Turn up cockpit lights to highest intensity to lessen temporary
D
blindness from lightning.
If using automatic pilot, disengage altitude hold mode and speed
D
hold mode.
increase maneuvers of the aircraft thus increasing structural stress.
If using airborne radar, tilt the antenna up and down occasionally.
D
This will permit you to detect other thunderstorm activity at altitudes
other than the one being flown.
Following are some do' s and don' ts during thunderstorm penetration.
Do keep your eyes on your instruments. Looking outside the cockpit
D
can increase danger of temporary blindness from lightning.
Don' t change power settings; maintain settings for the
D
recommended turbulence penetration airspeed.
Do maintain constant attitude; let the aircraft ride the waves.
D
Maneuvers in trying to maintain constant altitude increase stress on
the aircraft.
Don' t turn back once you are in a thunderstorm. A straight course
D
through the storm most likely will get you out of the hazards most
quickly. In addition, turning maneuvers increase stress on the
aircraft.
Federal Aviation Administration (FAA) Advisory Circulars
A- 10
The automatic altitude and airspeed controls will
A28- 1146- 102- 00