PRIMUS
r
880
Digital
W
eather
Radar
System
A28-1146-102-00
Radar Facts
5-47
INTENSITY AIRCRAFT REACTION
REACTION INSIDE
AIRCRAFT
LIGHT
Turbulence that momentarily causes
slight, erratic changes in altitude and/or
attitude (pitch, roll, yaw).
Occupants may feel a slight
strain against seat belts or
shoulder straps. Unsecured
objects may be displaced
slightly.
MODERATE
Turbulence that is similar to light
turbulence but of greater intensity.
Changes in altitude and/or attitude
occur but the aircraft remains in
positive control at all times. It usually
causes variations in indicated
airspeed.
Occupants feel definite
strains against seat belts or
shoulder straps. Unsecured
objects are dislodged.
SEVERE
Turbulence that causes large abrupt
changes in altitude and/or attitude. It
usually causes large variations in
indicated airspeed. Aircraft may be
momentarily out of control.
Occupants are forced
violently against seat belts
or shoulder straps.
Unsecured objects are
tossed about.
Turbulence Levels
(From Airman’ s Information Manual)
Figure 5-34
Hail Size Probability
Whenever theradar shows a redor magenta target,the entirestorm cell
should be considered extremely hazardous and must not be
penetrated. Further support for this statement comes from the hail
probability graph shown in figure 5-35. The probability of destructive
hail starts at a rainfall rate just above the red level three threshold.
Like precipitation, the red and magenta returns should be considered
as a mask over more severe hail probabilities.
By now, it should be clear that the only safe way to operate in areas of
thunderstorm activity is to AVOID ALL CELLS THAT HAVE RED OR
MAGENTA RETURNS.