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

everses course. The course on which the signal builds brings
the aircraft approximately over the site of the emergency
signal.
d. Passage over the signal source is indicated by a
sharp rise in signal strength followed by a sharp drop, or a
complete momentary loss of signal. If the aircraft has homing
equipment, this track should bring it within range of that
equipment, and the aircraft should descend and locate the
source by both homing and visual detection. If the aircraft
does not have homing equipment and a signal drop occurs, the
crew should note the position and descend immediately and
conduct a visual search around that point.
e. If a signal drop is not detected, the pilot should
proceed on course until the signal is lost, reverse course,
proceed to the midpoint of the second track, and then descend
and conduct a visual search.
3. Similarly, en route commercial aircraft may help determine an
approximate position of ELTs or EPIRBs by marking the position
when they first hear the signal and when they lose the signal.
A line connecting these two points should mark the chord of a
circle with the EPIRB/ELT close to the center. After several
such chords are obtained, the center of the circle can be
determined. See Figure 6-5.
D. Executing Aircraft Intercepts. See Vol. II, Chapter 7.
643 Vessel Search
A. All preparations should be completed before the vessel enters
the search area. Communications should be established with the OSC, SAR
frequencies and homing equipment guarded, observers positioned, and
rescue gear readied. Scanners should have binoculars and should be
stationed as high as possible to increase sighting range. A 360 degree
lookout should be maintained.
B. Marine craft searching where no electronic or visual reference
points exist should maintain a dead reckoning (DR) plot of the best
known position of the incident, their own position, and the position of
other ships and aircraft in the vicinity. The plot should also show the
date, time, possible drift of survivors, and areas searched.
6-7