d. Unit SOP will determine what type of marking is used. In largely congested
areas, the inverted Y touchdown marking may be indistinguishable from the abundance
of other lights. In the tactical setting, it may be impractical and too time consuming to
set up. Flashing lights and strobes may look like the muzzle flash from small arms fire
under night vision conditions and may give away the location of the unit. A simple
device like an infra-red chemical light on a string that can be spun over the head of the
signal man may be the most effective method of signal.
5-31. MARKING OBSTACLES
Mark obstacles at or near the landing site that cannot be removed and that may
not be readily seen by the pilot (cables, wires, antennas, large rocks, and so forth). If possible,
place a red light on top of the obstruction or mark the obstacle with brightly-colored or
fluorescent cloth. If the combat situation makes it impractical to mark the tops of the
obstacles, advise the pilot of their existence by radio.
5-32. OTHER LANDING AIDS
As the air ambulance approaches, provide the pilot with tactical and security
information and conditions that may affect the landing such as terrain, weather, landing
site markings, and possible obstacles. Confirm information or answer any questions the
pilot may have pertaining to the landing site. Continue to maintain communications with
the pilot during the landing.
a. Once the helicopter is within your area, the pilot will establish radio contact to
obtain positive identification. Orientate the pilot to the landing site using the 12 o'clock
method. [Twelve o'clock is always in the direction of the helicopter's flight.] Tell the
pilot the direction of the landing zone (LZ) from his location. For example, if the landing
zone is directly to the pilot's right, you might transmit, "The LZ is now at 3 o'clock to your
b. The pilot can also use FM (frequency modulation) procedures to home in on a
field radio transmitting between 30 and 70 megahertz. The FM field radio is limited to
line of sight; therefore, the person using the field radio should remain as clear as
possible of obstructions that could block the signal. If the pilot requests the operator to
"key the microphone," the operator should depress the transmit button on the field radio
for a period of 10 to 15 seconds.
c. When the helicopter is approaching the landing site at night, personnel on the
ground can request the pilot to turn on his beacon briefly. The ground personnel can
then confirm the helicopter's location in relation to the landing site and guide the
helicopter to the landing site.