ammunition from the ammunition pak to the gun transfer unit in the gun pak. The
gun system is remotely fired by pilot cockpit controls. Major components of the
gun system consists of a 25mm gun, gun system drive unit and speed control,
ammunition handling system, electrical controls, blast suppressor and structures
and fairings. The drive power for the gun system shall utilize engine bleed air.
3.1.1 Gun system functional diagram. The gun system breakdown structure
and functional flow block diagram are shown in Figures 1 and 2.
3.1.2 Gun system interface definition. The gun system shall be installed on
the integrated into the AV-8 aircraft. The major comonents shall interface
mechanically, functionally, and electrically with each other and with the air-
craft in accordance with the requirements specified herein and in other
220.127.116.11 Aircraft interface definition. The gun system shall be installed
on an integrated with the aircraft in accordance with the applicable requirememts
of MIL-I-8670. The ammunition pak and the gun pak shall mount to the aircraft by
means of gun pak attach points.
18.104.22.168 Electrical interface definition. The gun system shall accept, be
controlled by, and provide the electrical signals as follows:
a. Master arm. The master arm function shall activate the gun control unit.
Without this signal, the gun system shall not respond to any control
b. Gun select. The gun select function signal shall cause the gun system to
be replaced in a ready-to-fire condition.
c. Trigger. The trigger function shall cause the gun system to fire.
Removal of the trigger signal shall cause the gun to cease fire and
d. Unlear gun signal. The system shall provide a signal to the aircraft to
indicate that the gun did not clear after firing a burst.
e. Rounds remaining. The gun system shall provide a signal to actuate the
appropriate counter in the cockpit to indicate the number of rounds
remaining to be fired within +20 rounds.
All control functions shall be 28 volts direct current Vdc nominal. The arm
function shall be not greater than 5 ampers (A) maximum. The full firing current
shall be not greater than 15 A total.
22.214.171.124 Ammunition interface. The gun system shall accept, store, handle,
and fire, without adjustment. Standard Service Class 25mm ammunition as follows
a. M792, High Explosive Incendiary - Trace (HEI-T), AS12013545.
b. M793, Target Practice - Traced (TP-T), AS12013518.
c. XM794, Dummy Ammunition.