transmitter that, when properly activated,
transmits a tone-modulated radio frequency signal
on the emergency guard frequencies of 8.364 MHz
and 243.0 MHz simultaneously. The transmitting
set includes an inflatable float assembly that keeps
the transmitting set afloat at sea, and provides a
support platform on land. The entire set is packed
in a carrying case for stowing in a life raft.
The transmitting set is intended for signaling
the location of downed aircraft or airmen.
Because it provides signals in both the high
frequency (HF) and ultra high frequency (UHF)
portions of the spectrum, it can be detected by
search aircraft, surface vessels, and coastal-based
stations at considerable distances.
The battery pack is designed to provide 72
hours of continuous operation at 25°C (77°F)
with at least 250 milliwatts of output from each
transmitter at the end of this period. The
transmitting set will continue to transmit until the
battery pack is completely discharged.
Modulation of the transmitter is by internal
means only. No provision has been made for voice
or code communications, or for receiving signals
from search craft.
To prepare the radio for use is a simple
procedure.
1. Pull the free end of the UHF antenna
through the grommet in the float assembly to
allow the antenna to stand vertically.
2. Unscrew the top section cap of the
telescopic HF antenna, and pull the antenna out
to its full length. When fully raised the antenna
sections are alternate black and gray with the top
section gray. The antenna, when fully extended,
is approximately 9 feet high. (See figure 5-12.)
3. Pull out the switch safety pin (fig. 5-11).
4. Turn the POWER toggle switch to ON (fig.
5-11).
5. Place the entire assembly in the water and
tow it behind the life raft.
6. When operating on land, be sure the
transmitting set is placed on level ground so that
the antennas are vertical. Do not stand close to
the transmitting set because this can cause changes
in the radiation pattern of the transmitted signals.
7. If desired, the safety pin can be replaced
to prevent the transmitting set from being turned
off accidentally.
HELICOPTER RESCUE DEVICES
Every Aircrew Survival Equipmentman should
be familiar with the equipment used in rescue
Figure 5-12.—Transmitting set, radio,
flotation collar.
239.442
AN/PRT-5 with
from the sea or land by helicopters. (Refer to
Navy Search and Rescue Manual, NWP 19-1, for
procedures and techniques involving at-sea
aircrew rescues.) The helicopter’s ability to land
and takeoff in a small area and to hover over a
spot lends itself very effectively to rescue work.
There are three methods by which a helicopter
may make a rescue. The first is by hovering, the
second by landing, and the third by making a low,
slow pass with the rescue device hanging near
ground level. The latter is used mainly in hostile
areas when the helicopter pilot does not wish to
present the aircraft or the survivor as a stationary
target for enemy gunners. By far, the most
common helicopter pickup is made by hovering.
5-12
