Beechcraft Musketeer Sport III A23-19 Pilot Operating Handbook page 249

Oeechmłft
Single Englne {Piston)
Sectlon X
Safety lnformatlon
Thunderstorms build and dissipate rapidly. Therefore, do not
attempt to plan a course between echoes using ground
based radar. The best use of ground radar information is to
isolale general areas and coverage of echoes. You must
avoid individual storms from in-flight observations either by
visual sighting or by airborne radar. lt is better to avoid the
whole thunderstorm area than to detour around individual
storms unless they are scattered.
Remember that while hail always gives a radar echo, it may
fali several miles from the nearest visible cloud and hazard-
ous turbulence may extend to as much as 20 miles from the
echo edge. Avoid intense or extreme level echoes by at
least 20 miles; that is, such echoes should be separated by
at least 40 miles before you fly between them. With weaker
echoes you can reduce the dislance by which you avoid
them.
Above all, remember this: never regard any thunderstorm
lightly. Even when radar observers report the echoes are of
light intensity, avoiding thunderstorms is the best policy. The
following are some do's and don'ts of thunderstorm avoid-
ance:
1. Don't land or take off in the face of an approaching
thunderstorm. A sudden gust front of low level turbu-
lence could cause loss of control.
2. Don't attempt to fly under a thunderstorm even if you
can see through to the other side. Turbulance and wind
shear under the storm could be disastrous.
3. Don't fly without airborne radar into a cloud mass con-
taining scattered embedded thunderstorms. Embedded
thunderstorms usually can not be visually circumnavi-
gated.
4. Don't trust visual appearance to be a reliable indicator
of the turbulence inside a thunderstorm.
May, 1994
10-31