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

c. This track spacing may exceed the limits of SRU
navigation capability. Therefore, the assigned track spacing
should be either the calculated value or the minimum feasible
for the assigned SRU, whichever is greater.
5. Calculate attainable coverage factor for each SRU:
C = W/S
6. Determine attainable search area for each SRU:
A = V x S x T
and sum these values to obtain the total attainable search
area:
At = A1 + A2 + ... + An
where n is the number of available SRUs. This formula does
not include additional time for making search pattern turns
which, compounded over a full day of search, could be
considerable. Therefore, aircraft should be instructed to
start turns 15 seconds prior to the computed time of reaching
the end of the search leg, which makes the formula
sufficiently accurate. Wind and current will also affect
search effectiveness.
7. Base POD for the entire search on the overall coverage factor:
C = Zt/At
542 Partitioning The Search Area
A. The computed search area is divided into subareas to be
searched by SRUs, the number of subareas depending on the number of SRUs
available. The size and orientation of the subareas depend on the
capabilities of the SRUs and on environmental factors, such as the sun
or swell direction. Elongated search areas are better for navigation
than small squares.
B. Establishing Individual Search Area Sizes. This is done by
means of:
An = V x S x T. To determine subarea dimensions:
1. The estimated search subarea length (l') will be the smaller
of:
a.
b. The distance that could be covered in 30 minutes for
fixed-wing aircraft;