TM 1-1520-238-10
4-2
Change 4
4.3 FLIGHT SYMBOLOGY.
The flight symbology has four modes; cruise, transition,
hover, and bob-up. The symbology modes (fig 4-1) arese-
lectable using the flight symbology mode switch on the cy-
clic. The symbols are defined in table 4-1.
WARNING
When conducting sea operations the
velocity vector in the pilots symbology
will indicate the speed of the aircraft
relative to the earth and not to the ship.
The pilot flight symbology, particularly the velocity vector,
is always driven by inertial velocity. The indicated velocity
is relative to actual motion over ground or water. When at-
tempting to move or hover near or over a moving platform
(such as a ship), the relative velocity between the aircraft
and the moving platform is different than the true inertial
velocity indicated by the velocity vector. If hovering over a
ship moving at 10 knots through the water, the velocity
vector will indicate 10 knots, not 0 knots, which is the rela-
tive velocity between the aircraft and the ship. For this sit-
uation the pilot must use visual cues to derive the actual
relative motion with respect to the moving platform. The
velocity vector must not be used as an indiator of relative
motion between the aircraft and moving platform, since it
will be inaccurate to the degree of the platforms’ velocity
through the water.
