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

Figure 7-2. Helicopter Racetrack Escort Pattern
b. Although helicopters operate at night and in nearzero
visibility, they require more time to maneuver under
these conditions. Radio discipline is essential for
uninterrupted crew communication during the approach, and to
permit DF equipment to give a steady bearing when homing.
Aircraft should avoid transmitting to helicopters executing a
hoist.
c. In dropping flares, aircraft should exercise extreme
caution when helicopters are in the search area. A descending
parachute flare (lighted or unlighted) is hazardous to
helicopter rotors, degrades effectiveness of night visual
detection aids (pyrotechnics, strobe lights, and flashlights),
and may induce vertigo to helicopter pilots during low
visibility conditions. Flares should be dropped only when
requested by the helicopter.
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