Design Requirements. Facility Plate No. 116-15 indicates facility
layouts for four types of aircraft and details of nozzles and outriggers.
a) Provide water at 100 to 150 pounds per square inch at the spray
nozzles for each type of pad. A booster pump and storage tank shall be
provided to maintain specified quantity and pressure of water.
b) Provide drainage into sewer system. See MIL-HDBK-1005/9.
Consider use of oil water separator and waste oil holding tank on drain line.
c) Pavement shall be portland cement concrete designed to the same
criteria as the aircraft washrack (paragraph 8.2).
d) The angle of water impinging on engine air intake is critical.
Adjustable nozzles shall be used and regulated to prevent water from being
sprayed into the engine intake.
e) Rotary-wing aircraft require the use of 10 to 12 gpm 15-degree flat
spray pattern nozzles to overcome helicopter blade downdraft along with
30-degree and solid spray nozzels. Fifty gpm solid stream nozzles should be
used for outrigger or edge of pavement placement to impinge on top of
helicopter blades and fuselage. See Facility Plate No. 116-15, sheet 1 of 8.
f) Fixed-wing VP type aircraft should use a 15-degree flat spray
nozzle at 10 to 12 gpm throughout the facility. Outrigger or edge of pavement
50 gpm solid stream nozzles may be needed to impinge on tail sections. See
Facility Plate No. 116-15, sheet 2 of 8.
g) Fixed-wing VA and VF type aircraft require 30-degree flat spray
nozzles at 10 to 15 gpm. See Facility Plate No. 116-15, sheet 3 of 8.
h) Tilt rotor (V-22) aircraft require a combination of 15- and
30-degree flat and solid spray nozzles. See Facility Plate No. 116-15,
sheet 4 of 8.
Aircraft Compass Calibration Pad. An aircraft compass calibration pad
provides a suitable area in which to calibrate aircraft compasses. Type I
pad is for use with a magnetic compass calibration set. Type II pad is for
use with or without the magnetic compass calibration set. It includes a
compass rose and turntable to accommodate aircraft which are not adaptable to
the com-pass calibration set.
Location. The compass calibration pad shall be located in an area
as free as possible from local magnetic disturbances. The direction and
uniformity of the earth's field shall be determined prior to use of the area
for compass swinging. Magnetic interference shall be checked annually
thereafter. Any changes in physical features of the site that might result
in a magnetic disturbance, necessitates an immediate resurvey to determine if
the uniformity of the earth's field has been adversely affected. The magnetic
compass calibration set includes equipment and technical manual for making an