compressor (GTC) used to provide air and electrical
power for starting aircraft jet engines. The start unit
contains all the components and fuel supply necessary
for independent operation. The start unit requires
manual start initiation/stop and manual air selection.
Once started, an engine control system regulates start,
acceleration, and engine operation. Air start hoses and
electrical cables are provided. This unit is used aboard
shore stations.
A/S47A-1 Jet Aircraft Start Unit
The A/S47A-1 jet aircraft start unit (fig. 9-20) is a
tractor-mounted, self-contained, mobile aircraft turbine
engine air start unit. The air start unit enclosure consists
of a control panel, enclosure assembly, gas turbine air
compressor (GTC), stowage rack for the air start hose,
and turbine support and mounting assembly. Except for
fuel and electrical power (supplied by the tractor), the
enclosure contains all systems necessary for gas turbine
engine operation. This unit is used aboard ship and on
shore stations.
WARNING
Hot exhaust from a jet aircraft start unit is a
serious hazard when operating in close proximity
to aircraft, aircraft components, fuel, weapons,
equipment, and personnel.
You must take extra special precautions as to where
a gas turbine compressor (GTC) is positioned during
operation, especially aboard ship where aircraft are
parked closely together. High volume air pressure,
extreme exhaust temperatures, jet intake suction, high
noise levels, and unqualified operator's are all potential
hazards.
A/M27T-5 Hydraulic Portable Power Supply
The A/M27T-5 hydraulic portable power supply
(fig. 9-21) is a self-contained, single-system, hydraulic
pumping unit powered by a three-cylinder, two-cycle,
diesel engine with a rated capacity of 20 gpm at 3,000
psi and 10 gpm at 5,000 psi. During normal operation
the diesel engine runs at speeds up to 2,500 rpm. The
A/M27T-5 engine operates on JP-5 (jet fuel) or diesel
fuel, and the hydraulic reservoir holds 20 gallons.
Pressure and return hydraulic hoses, a tow bar, tie-down
rings, and a manual hand brake are provided.
A/M27T-7 Hydraulic Portable Power Supply
The A/M27T-7 hydraulic portable power supply
(fig. 9-22) is similar in operation to the A/M27T-5
except for its source of power. The A/M27T-7 is
powered by a 50 horsepower electric motor. A 50-foot
power cable is provided for connection to an external
440-volt, 3-phase, 60-hertz power source and can be set
up to operate on a 220-volt source. The hydraulic
reservoir holds 16 gallons and is equipped with a fluid
level sight gauge. Pressure and return hydraulic hoses, a
tow bar, tie-down rings, and a manual hand brake are
provided.
9-12
ANF0920
Figure 9-20.—A/S47A-1 tractor-mounted jet aircraft start unit.
