JP 3-50 National Search and Rescue Manual Vol I - US Navy

Air search radar
Surface search radar
Radar range and visual bearing
DR position
b. A fix or DR should be plotted:
(1) Initially, every 15 seconds on the air plot. This
provides the air controller with the best
presentation on the aircraft track and allows more
precise control.
(2) Every 30 seconds on the air plot after wind drift
correction is established.
(3) Every 60 seconds on surface plots.
6. Air controller procedures
a. Use the air plot as the primary means of
coordination, to ensure that the aircraft will pass overhead
the vessel on each searchleg.
b. Correct the aircraft back to the search course
whenever it is off more that one-quarter mile.
c. Pin down drift as early as possible. Frequent
corrections to track reduce search effectiveness, because the
pilot is distracted from scanning, and the lowered wing
obstructs visibility for that lookout while the upwing lookout
can see only sky.
d. Base track corrections on the trend of several marks
and determine new headings by inspection of aircraft drift, if
consistently into or downwind. If a heading change of more
than a couple of degrees is necessary to hold the aircraft on
track, recheck computations for X and Y. If original
computationS are correct, check for change in wind or aircraft
TAS. Recompute X and Y with new values and replot bowtie.
e. Direct aircraft to "execute crossleg" when it reaches
the lead mark (time to turn mark). The aircraft follows
crossleg instructions passed previously and keeps its own time
on straightaway. The vessel does not attempt to coordinate
the aircraft on crosslegs. The air controller should correct
recurring overshoots or undershoots by adjusting time on
straightaway.
E-10