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

3. Maneuverability is necessary for SAR in mountainous areas but
is less crucial for SAR over flat terrain. A measure of
maneuverability is the smallest safe turning diameter. As
turning diameter generally increases directly with true
airspeed (TAS), a rule-of-thumb to compute fixed-wing turning
diameter, in nautical miles, is:
TAS + 10 = TURNING DIAMETER (NM)
100
4. Weather affects SRU capability to operate. Generally, the
larger the SRU, the better the capability. Helicopters may
have limited weather capability and some are prohibited from
flying in conditions worse than light turbulence or light
icing. Most SRUs are prohibited from flying in thunderstorms,
severe turbulence, and severe icing. Weather conditions en
route, on scene, and at the SRU departure airport must be
considered.
5. Lookout transport is a major function of SRUs. The larger the
number of lookout search positions, the more suitable the SRU.
Aircraft with only one pilot are the least effective.
Aircraft are high-noise, high-stress platforms on long
missions, causing fatigue which decreases lookout
effectiveness and flight safety. Multiple SRUs and shorter
sorties, rather than fewer SRUs with longer sorties, are
preferable.
6. Electronic capabilities may determine SRU ability to
effectively navigate and complete a SAR mission, and also
determine SRU mission use.
a. Accurate navigation is essential not only for safety,
but for search area coverage and reporting survivor position.
Some small SRUs are not equipped with instrumentation adequate
for flight under instrument flying rules (IFR). If instrument
meteorological conditions (IMC) are forecast for any portion
of the mission, the aircraft must have full instrumentation
and a pilot licensed for instrument flight.
b. SRUs should, as a minimum, be able to communicate
with the OSC. Communication with the distressed craft or
survivors is desirable, but may not be possible. Long-range
SAR aircraft usually have communications capabilities
comparable with medium-size ships. Sensors such as DF
equipment and radar, which electronically detect the search
object or survivors, often allow SRUs to expand track spacing.
7. Use also may be affected by other capabilities and equipment,
such as the ability to make short field or amphibious
landings, add auxiliary fuel tanks to increase range, effect
rescue or aerial delivery, provide emergency care and life
support, provide on scene illumination and contact with
survivors, or self-start in remote areas.