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

Figure 6-3. Close Track Spacing
on the assumption that the area of equal beacon signal
strength is circular.
a. When the emergency radio signal is first heard, the
pilot adjusts receiver volume for normal listening and
receiver squelch to the point where the signal is just lost.
The squelch is then readjusted until the signal is just
audible, and the position noted.
b. Continuing on the same course, and without adjusting
the radio controls, the pilot notes the position when the
signal is lost and reverses course along the same track. Half
way between the points where the signal was heard after the
initial squelch adjustment and where it was again lost is the
closest point to the emergency transmitter along the track.
The source is approximately 90 degrees to the right or left of
this midpoint.
c. The pilot then makes a 90 degree right or left turn.
The signal will either fade or build as the aircraft continues
on the new heading. If the signal fades, the aircraft