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

The craft's float or flight plan is particularly helpful. Once
departure and non-arrival are confirmed, probable locations along the
route should be checked. Communication searches can either locate the
craft or eliminate areas that would otherwise need to be physically
searched. An SMC may also dispatch SRUs to check specific locations or
to overfly the likely route. If the overdue craft is not located, the
SMC then decides whether or not to search other areas.
443 Urgency of Response
A. The nature of the incident and the rate at which the situation
may worsen usually determine the urgency of response. The SAR system
should provide prompt and effective assistance to all incidents,
particularly those that need rapid response.
B. The time to begin searching may depend on the amount of
daylight remaining. Since the chances of survival diminish with time, a
few hours of searching during remaining daylight may be more productive
than waiting until the next day for a full-scale search effort.
Influencing factors are the number of SRUs available and the seriousness
of the incident. For a known distress, an SRU, preferably the quickest
response SRU, should be immediately dispatched to confirm the distress
position.
C. SAR incidents are time-critical
1. Survival times vary with local conditions, such as terrain,
climate, ability and endurance of survivors, and emergency
survival equipment and SRUs available.
2. It should be assumed that all survivors are incapacitated,
capable of surviving only a short time, under great stress,
experiencing shock and requiring emergency medical care.
Normally able-bodied, logical-thinking persons may be, as
survivors, unable to accomplish simple tasks or to assist in
their own rescue. Some may be calm and rational, some
hysterical, and others temporarily stunned and bewildered.
This last group will generally be passive and easily led
during the first 24 hours after the incident. As
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