Figure 3-11.-NR-5C mobile air-conditioning unit.
full accessibility. Four lifting rings are mounted
that are controlled by two parking brake handles
on the upper corners of the unit, and four tie-
mounted on the front of the vehicle.
down rings are mounted on the bottom corners
GAS TURBINE COMPRESSORS (GTCs)
of the unit.
Gas turbine compressors supply compressed
NR-10 Mobile Air-Conditioner
air for systems requiring large quantities (volume)
The NR-10 mobile air-conditioner is also a
of air at low pressure. The gas turbines you will
trailer-mounted, self-contained, air-conditioning
be using are used to supply air for starting jet air-
unit. See figure 3-12. A six-cylinder, turbo-
craft engines. Some of the units also include a
charged, diesel engine supplies all the power for
power generating system.
the operation of the air-conditioner.
Anytime you are around GTCs you must be
The engine is liquid cooled by means of a
aware of the dangers associated with them. A
radiator. Airflow through the radiator is provided
noise hazard exists anytime you are around GTCs.
by the condenser fan. The trailer assembly
The exhaust gases of the GTC are also very
consists of the tow bar and four independent
hazardous. Hot, high-velocity gases can burn you
suspension wheels. The tow bar assembly is
or any part of the aircraft they hit. If the aircraft
designed so that when the front wheels attain their
is loaded with external fuel tanks or weapons, the
maximum angular position, a cam on the tow bar
exhaust can be extremely dangerous. Another
assembly is released, allowing the tow bar to
danger comes from the high-pressure air in the
air start hoses. Disconnects or ruptures happen
continue following the motion of the towing
vehicle. All four wheels are provided with a
most often during the initial surge of air through
the hose. A flailing hose end can severely injure
hydraulic braking system on the tow bar for
personnel and damage the aircraft.
towing, and all four wheels have parking brakes
3-10
