General Dynamics unit delivers new Gun System. (Women in Defense).

General Dynamics Armament and Technical Products, of Burlington, Vt., has begun--a month ahead of schedule--to deliver 39 F/A-18 E/F 20mm M61A2 Gun Systems to the Naval Air Systems Command, at Patuxent River Naval Air Station, Md., according to GDATP President Linda Hudson. GDATP is a unit of General Dynamics Corporation, of Falls Church, Va. Hudson also is a member of WID.

"We started on schedule, and we are one month ahead of the contract delivery plan," she said. The contract, valued at up to $37.1 million, includes options for up to 126 additional gun systems over a three-year period.

The M61A2 is an improved version of a six-barrel Gatling gun system that the Navy has used on its F/A-18 strike fighters since the mid-1990s. Improvements include a lighter ammunition handling system, Hudson said. This was accomplished by reducing the number of rounds from 578 to 412 and replacing steel parts with composites and titanium.

The new system includes the very first use of an aluminum casting as a structural component, she said. The drum was shortened to make room for avionics. The M61A2 requires reduced depot-level maintenance and is less susceptible to breakage during installation and removal from the aircraft, Hudson said. In addition, the new system uses approximately 85 percent of the same parts as the version older version.

The M61A2 includes a new, lightweight barrel and fully integrated, linkless ammunition feed, Hudson explained. "The gun and ammunition feed system was specifically designed for this aircraft," she said.

"The one on the current F18 version is 52 pounds lighter than the gun system that was on the C/D version of the aircraft. It's more maintainable.

"Its lighter weight frees up space in the aircraft to allow the customer to do some other things--to increase range, to increase payloads, to do whatever they like," Hudson said. "All of this adds to the performance of the aircraft, in general.

"The F/A-18 E/F system has a selectable firing rate at 6,000 rounds a minute and one at 4,000 rounds a minute," she said. The 4,000 shots-per-minute rate is intended for air-to-ground target engagements, and the 6,000 shots-per-minute rate is meant for air-to-air engagements.

The F-18 has used the M61A2 lightweight gun since the mid 90's in both C/D and E/F versions. Prior to that, the F-18 had a heavier gun, similar to the one in the Air Force F-16 The F18 E/F version has been in production since 1997.

Reducing the Weight

"It was important to reduce the E/F gun system's weight and footprint, improve maintainability, and yet retain the lethality, rate of fire and reliability of the original C/D version," Hudson said. "This pursuit is consistent with our customer's goal to increase range, payload and speed of the Super Hornet.

"The linkless feed system eliminates the weight and handling of the ammunition links. The system is double ended and dosed looped. It cycles spent cases back into the drum to prevent such debris from being ejected overboard, thereby preventing a significant hazard for airframe and engine damage," she said.

The pilot--fitted with a joint helmet-mounted cueing system (JHMCS)--receives key information about the M61A2 gun through the system, Hudson explained. "In the JHMCF, the crosshairs, the 'gun-selected' indicator and the number of rounds remaining appears. But the gun is mounted fixed forward, and the way they aim the gun is by maneuvering the aircraft. So there is information on the helmet system, but the pilot does not actually move the gun with the helmet."

The gun system serves a vital role as the aircraft's last line of defense in dose-in aerial engagements, Hudson said. "The gun completes the spectrum of tactical lethality within the innermost envelope for the last line of defense. The high rate of fire and reliability are salient features of the gun system. When the pilots are out of missiles or bombs or are in too dose to use their missiles, they use the gun."

The gun system contributes to significantly lower operating and maintenance costs for the F/A18-E/F, compared to other Navy combat aircraft, Hudson said. "Both the C/D and E/F versions of this gun system were designed in what we call a palatine system. The whole unit can be easily removed and installed. The E/F version has been redesigned from the C/D version to make it less prone to damage during installation and removal, therefore, requiring fewer repairs."

GDATP produces gun systems for virtually all U.S. fighter aircraft, and has been doing so for the past 50 years, Hudson explained.

"We have the guns in the F-16, the F-15 E, and F-22," she said. "A whole host of older aircraft uses our guns.

In September, GDATP was selected as the gun-system integrator for the F-35 Joint Strike Fighter (JSF) by Lockheed Martin Aeronautics Company, in Fort Worth, Texas.

"It's not dear at this time what gun we're going to use," Hudson said. "We are going to do a trade study with Lockheed Martin to select the right gun for the aircraft. It may or it may not be a Gatling gun, depending on the needs and the operational requirements."

The F-35 program "is a significant anchor for us well into the future," with several thousand units expected to be produced in a variety of configurations, Hudson said.

Lois F. Brand is a WID member She is marketing and sales manager at the National Community Pharmacists Association, in Alexandria, Va.