PILOT’S
GUIDE
46
STRIKE FINDER
DIGITAL WEATHER AVOIDANCE
Hail
Hail is precipitation that falls from thunderstorms as round or irregular balls
of ice. The freezing process takes place when water droplets are
continuously rotated up and down by air currents within the cell of a
thunderstorm. Each time a water droplet is pushed by strong updrafts into
the cold upper layers, freezing occurs. The process repeats itself until the
weight of the hail stone causes it to fall or the updraft subsides enough to
allow hail to fall to the ground.
Be distance aware! Hail has exited thunderstorms from the long cirrus anvil
cloud, many miles distant from the storm center. Hail paths 20 miles
down-wind are not uncommon. The aircraft in
Figure 39
is a frightening
example of damage caused by hail.
Figure 39. Aircraft Damaged by Hail
Airframe Icing
Airframe icing occurs when the aircraft contacts supercooled water droplets
within clouds. Airframe ice seriously degrades the performance and control
of any airplane. All thunderstorms contain supercooled water droplets
and
must
be avoided.
Strike Finder Pilot's Guide fix 9/19/05 10:59 AM Page AY
