TM 55-1510-221-MTF
PROCEDURE
TROUBLESHOOTING
REFERENCE
G. AVIONICS FLIGHT CHECKS (CONT)
o.
Leg Switching - Check as follows:
(1)
INS - Set up for manual flyover when approaching
waypoint.
(2)
ALERT indicator - Monitor (The ALERT monitor
will illuminate approximately two minutes before
the waypoint is reached.)
(3)
Data selector - L/L POS (when approaching
waypoint).
(4)
HOLD key - Depress when closest to the
waypoint.
(5)
Present position readout - Record.
(6)
Error distance (if any) - Visually estimate between
the location at which the HOLD button was
pressed and the location of the waypoint.
(7)
Compare the frozen INS display of present
position with the coordinates of the waypoint,
taking into account the visually observed error
distance. This position error shall not exceed
1200 feet.
4-20
