after gun firing to ensure that all gases are cooled and
purged.
The F/A-18 gun gas purge system uses engine
bleed air and has an additional gas control provided by
a hydraulically actuated ram-air scavenge door that
opens automatically during gun-firing operations. The
gun gasses are vented through louvers in the lower
mold line of the aircraft fuselage.
REVIEW NUMBER 4
Q1.
What chute provides a path from the exit unit
to the adapter assembly?
Q2.
What chute provides a path from the transfer
unit to the entrance unit of the drum?
Q3.
What is the purpose of the gun gas purge
system?
Q4.
Describe the difference between the gun gas
purge systems of the F-14 aircraft and the
F/A-18 aircraft.
M61A1 GUN SYSTEM INSTALLATIONS
LEARNING OBJECTIVE: Identify M61A1
gun system installations to include those used
on the F/A-18 and F-14 aircraft.
M61A1 gun and ammunition handling system
installations
have
the
same
basic
components.
However, some components are peculiar to specific
aircraft. These differences are discussed in the
following paragraphs.
F/A-18 GUN SYSTEM INSTALLATION
The F/A-18 M61A1 gun system (fig. 6-14) is
internally mounted in the nose of the aircraft on the
centerline. The fired projectiles exit the aircraft through
the gun blast diffuser assembly, located just forward of
the cockpit windscreen. Depending upon the mission
objective, the gun can be operated in the air-to-ground
(A/G) or air-to-air (A/A) computer mode. There are
two A/G modes—continuously computed impact point
(CCIP) and manual (MAN). There are three A/A
6-15
Figure 6-14.—F/A-18 M61A1 gun installation.
