A/S47A-1 Tractor-Mounted Jet Aircraft Start
Unit Enclosure
The A/S47A-1 tractor-mounted unit enclosure (fig.
1-20) is a self-contained mobile turbine engine air start
unit. The air start unit enclosure consists of a control
panel, gas turbine engine, stowage rack, and turbine
support and mounting assembly. The enclosure
contains all systems necessary for gas turbine engine
operation except for fuel and electrical power.
Q1-40.
The A/M47A-4 jet aircraft start unit is trailer
mounted.
1. True
2. False
AS1f0319
MOBILE AIR-CONDITIONERS
Figure 1-21.--A/M32C-17 mobile air-conditioner.
Today's modern aircraft have an abundance of
electronic equipment that generates a tremendous
amount of heat, which makes air conditioning a
A/M32C-17 Mobile Air-Conditioner
requirement in the air or on the ground. This is done by
an onboard system, but the aircraft engines must be
The A/M32C-17 mobile air-conditioner (fig. 1-21)
operating for this system to work. This is not practical
is trailer mounted and powered by a 6-cylinder, V-71
on the ground when maintenance, testing, or calibration
Detroit diesel engine. The operating components are
require the electronic equipment to run for long periods
contained within a metal paneled housing and are
of time. Therefore, another form of air conditioning is
assembled into a refrigeration system, a ventilation
needed, and that is why we have mobile
system, a hydraulic system, and associated sensing and
air-conditioners. Mobile air-conditioners provide
control components. The trailer contains its own
filtered air for cooling, dehumidification, or ventilation.
braking system (surge brake), and the refrigeration
There are several different types and models, but this
system is serviced with R-22.
text covers only the two models that are commonly
used by the Navy--the A/M32C-17 and the
A/M32C-21 Mobile Air-Conditioner
A/M32C-21.
The A/M32C-21 mobile air-conditioner (fig. 1-22)
is trailer mounted and powered by a 30-horsepower,
440-volt, 3-phase, 60-Hz ac electric motor. A
60-foot-long external input power cable is stored on the
brackets at the rear of the unit. The two front wheels are
mounted close together on a caster assembly. A tow bar
AS1f0318
AS1f0320
Figure 1-22.--A/M32C-21 mobile air-conditioner.
Figure 1-20.--A/S47A-1 tractor-mounted enclosure.
1-25
