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

area, they must fly their individual patterns at different altitudes on
tracks which differ by 45 degrees. See Figure 5-35.
Figure 5-35.
F. Sector Patterns (V) are used when the position of a distress is
reliable or the area searched is not extensive, and a concentration of
effort is desired at datum. The pattern resembles the spokes of a wheel
and is used to cover a circular search area. A datum marker, in the
center of the area, aids navigation on each leg. Generally, aircraft
sector search areas do not have a radius greater than 20 to 30 miles,
while marine craft use a maximum radius of 5 miles. Because only a
small area is covered, datum should be recomputed on every search to
allow for drift. If the search is oriented over a marker, adjustment
for total water current (TWC) will occur automatically, and only leeway
must be considered. The CSP may be at the perimeter of the pattern or
at datum. Each leg is separated by an angle, based on the maximum track
spacing and search radius, and connected by a crossleg equal to the
maximum track spacing. For standardization, all turns should be made to
the right. An average POD for sector patterns can be determined by
using the mid-leg track spacing.
1. In Sector Single-Unit (VS) searches, four-sector and sixsector
patterns are most commonly used. See Figure 5-36.
a. The six-sector pattern is easiest since it
5-38