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

APPENDIX E. COORDINATED SEARCH PATTERNS
A. Coordinated Patterns
This appendix provides OSCs with a guide for planning and executing
coordinated search patterns. Teaming an aircraft with a vessel takes
advantage of each SRU's best features. Aircraft provide rapid coverage
of the search area from a good search platform. Vessels may provide
better navigation, unless the aircraft is equipped with sophisticated
navigational aids such as INS, and may be able to quickly rescue a
survivor sighted from the aircraft.
B. Coordinated Search Symbology
The following symbols and definitions are used in computing and
discussing aircraft search tracks.
Al is the search area length.
Aw (search area width) is the sum of one searchleg and one track
spacing (Aw = L + S).
Awf is the search area width for faster aircraft in CMCS pattern.
Aws is the search area width for slower aircraft in a CMCS pattern.
C (course) is the intended path of travel by an SRU.
GS (ground speed) is the speed of an aircraft relative to the
earth's surface.
H (heading) is the horizontal direction in which an SRU is
pointing.
L (searchleg or searchleg length) is the sum of the searchleg
straightaway (y) and the search craft's turn diameter (TD). Subscripts
further define L.
L1 is the searchleg with the highest headwind component.
L2 is the searchleg with the highest tailwind component.
S (track spacing) is the distance between adjacent searchlegs.
t1 is the time required for a search aircraft to fly one-half of
the straightaway length (Y1) of the searchleg with the highest headwind
component (L1).
t2 is the time required for a search aircraft to fly one-half of
the straightaway length (y2) of the searchleg with the highest tailwind
component (L2).
t3 is the time required for a search aircraft to fly the full