If the system fails any of the internal tests, an
error message will display indicating what test failed
and what functions may be inoperative. In most
cases, all other systems will continue to operate. If
continued operation is possible, the message, PRESS
ANY KEY TO CONTINUE, will display.
When initially turned on, the system may
complete its self-test program before the CRT comes
on. In that case, it is possible that the first message
that will be seen is the main menu. This is normal
If the weather screen is selected immediately, it
is possible the advisory message FLAG will display
where heading information is normally displayed. This
usually means the gyro system has not yet come up to
speed. FLAG should be replaced with heading
(2) Main Menu. The main menu provides
access to the two weather mode views and additional
information, options, and navaid display. To select a
specific menu item, press the NEXT button on the
display until the desired item is highlighted. Then
press the GO button to view the selected menu item.
(3) Weather Modes. Two weather mode
views are available from the main menu by pressing
either the 360° button or the 120° button. The symbol
® means go to. When the weather mode is initially
selected, it will always be in the 200 nm range.
Pressing the button beside the range setting will cycle
through the additional range selections from 200 nm to
100 nm to 50 nm to 25 nm and back to 200 nm. The
25 nm range is indicated by a solid ring to advise of
close proximity to potential thunderstorms. Either view
can be selected from the main menu or the opposite
view. When changing from one view to another, the
range remains constant.
The 120° view provides an expanded view and
therefore thunderstorm information is displayed in
greater detail. Refer to Figure 3C-23.
Press the CLEAR button to erase all weather
data from the display and system memory. The
intensity of a thunderstorm can be identified by the
speed with which the discharge points appear. The
system continually receives and processes new
electrical discharge information. Monitor this by
pressing the CLEAR button often. The more intense
the storm, the faster the discharge points reappear.
Figure 3C-23. 120° Weather Mode
Multiple discharges, which appear as clusters,
are indicative of thunderstorm activity. A large number
of discharge points indicate a faster rate of occurrence
and, therefore, a more severe thunderstorm. Fewer
necessarily, weaker, cell. Thunderstorm conditions
change rapidly and monitoring their activity over a
period of time by use of the CLEAR button is
recommended. Any grouping of discharge points
within the 25 nm range is cause for immediate
The Stormscope System should never be
used to attempt thunderstorm penetration.
The FAA and AIM recommend avoiding by
identified as severe or giving an intense
discharge points indicate thunderstorms.
There are several atmospheric phenomena
that can cause isolated discharge points.
Clusters of two or more discharge points
indicate thunderstorm activity when they
re-appear persistently after clearing the
Additionally, should the heading stabilization fail,
it is necessary to press the CLEAR button for properly
oriented data following an aircraft heading change.