LMTAS completes fit check of F-22 gun system

LMTAS completes fit check of F-22 gun system

11 January 2000

Representatives from the F-22 System Programme Office and Air Combat Command observed as the first gun system was slid into position into the eighth flyable mid-fuselage manufactured by Lockheed Martin Tactical Aircraft Systems in Fort Worth. This first fit check of the F-22 Raptor's 20 mm gun system, called the Linear Linkless Ammunition Handling System, was deemed a complete success.

"We took the qualification gun system and perfectly fit it into the midsection of 4008 without one single envelope violation," said SMSgt. Rod McDowell, a representative of the Armament Integrated Product Team for the F-22 System Programme Office. "This is a real success story. This flawless fit check did not just happen because of luck, it happened out of a lot of dedication and hard work."

In addition to the installation and removal of the 20 mm gun and ammunition container, many other gun system components were connected and demonstrated, including the adjustment and actuation of the gun safeing mechanism, the compatibility and accessibility of the gun loader system interface and access to all gun-related maintenance items.

The F-22 gun system incorporates many design improvements over previous systems. The system has met extremely challenging weight goals while providing many innovative maintainability features. Several major system components have been integrated or eliminated to simplify gun system installation and removal. The system, which contains 480 rounds of 20 mm ammunition, is capable of feeding ammo to the gun at a rate of 100 rounds per second. To maintain aircraft stealth, the system includes integral hydraulic features that operate fast-acting port and purge system doors.

The ammunition handling system is manufactured by General Dynamics Armament Systems. Qualification testing of the system, including extensive live-fire testing, has been completed. The qualification system used in the fit checks had previously fired more than 80,000 rounds of 20 mm ammunition successfully in separate tests. (One aircraft lifetime is represented by 52,000 rounds.) Airborne gun fire testing is anticipated to begin on the third flying F-22 in mid-2002, though flight test scheduling opportunities may permit firing before that date.

Tactical Aircraft Systems, a major participant in the F-22 programme, is responsible for the mid-fuselage section; electrical, hydraulic, fuel and armament subsystems; flight control system; electronic combat; communication, navigation and identification systems; and the stores management avionics. Programme management and final assembly are based in Georgia.

Defence Systems Daily