The gun on the F-35 Joint Strike Fighter jet will fire in 2017, according to the Pentagon.
Joe DellaVedova, a spokesman for the F-35 program office, said the fifth-generation stealth fighter's GAU-22 gun and the Electro-Optical Targeting System -- two key systems to provide close air support to ground troops -- will be operational with the installation of the Block 3F software update in fiscal 2017.
The Jan. 7 statement from the program office followed recent news articles in The Daily Beast quoting unnamed Air Force officials saying the gun won't work for most pilots until 2019 and that the targeting system is already outdated compared to similar systems on existing fourth-generation fighters.
"I'd like to help clear the air on some nameless/sourceless/baseless reporting," DellaVedova wrote in the e-mail. He defended the systems, though disclosed a software glitch related to the gun and acknowledged the EOTS will need to be upgraded to include the latest targeting features. (Daily Beast reporter Dave Majumdar responded to the statement with another article, "Pentagon Misfires in Stealth Jet Scandal.")
The Pentagon plans to begin testing the gun on all three models of the Lockheed Martin Corp.-made F-35 this summer, DellaVedova said.
"Comprehensive flight test on the F-35A variant GAU-22 25mm gun system is scheduled to begin mid-year at Edwards AFB, Calif., and will include ground fire tests, muzzle calibration, flight test integration and in-flight operational tests," he wrote.
The GAU-22/A, a four-barrel version of the 25mm GAU-12/U Equalizer five-barrel cannon found on the Marine Corps' AV-8B Harrier II jump set, is designed to be internally mounted on the Air Force's F-35A conventional model of the aircraft and hold 182 rounds. It's slated to be externally mounted on the Marine Corps' F-35B jump-jet variant and the Navy's F-35C aircraft carrier version and hold 220 rounds.
That's a drop in the bucket compared to the 30mm, seven-barrel GAU-8/A Avenger in the nose of the Cold War-era A-10 Warthog attack aircraft, which holds as many as 1,174 rounds.
But it's actually more than the capacity of other existing front-line fighters, including the Russian MiG-25 and Eurofighter Typhoon, and enough to perform the close air support mission, according to Dave Stouffer, senior manager of business development at General Dynamics' Ordnance and Tactical Systems unit.
"I love the A-10, I'm a former infantry guy," he said in a telephone interview with Military.com. "No one is going to sit here and say it's going to be just as good as the A-10." But, he added, "This 25mm in the Joint Strike Fighter can perform the ground support role ... This is a very capable gun system."
The weapon, one of many slated for the aircraft, is based on a design with a proven track record on both the Harrier and the AC-130 gunship, he said. Linked to the aircraft's fire control and targeting software, it will fire highly accurate rounds at air-to-ground or air-to-air targets, he said. Also, the exposure point -- the time it takes for the pilot to point the plane and its gun at a target -- may only last a fraction of a second, translating to nine or 10 bursts of fire, he said.
The company has delivered about 75 of the guns to Lockheed Martin, according to spokeswoman Laurie VanBrocklin. "The weapon systems meet the performance specification of the JSF program and have completed a comprehensive acceptance test," she said in an e-mail.
Meanwhile, computer lab testing of the 3F software in December revealed "a minor low-level issue with aircraft software that impacted the interface with the gun," DellaVedova said. "This discovery was part of normal software development and testing and a plan is in place to resolve this issue by spring," he said. "There is no anticipated impact to scheduled gun testing or fielding."
Software problems are nothing new to the program.
Frank Kendall, the Pentagon's top weapons buyer, and Air Force Lt. Gen. Christopher Bogdan, who manages the acquisition effort, have raised concerns over F-35 software development. The Block 3F software, which supports the aircraft's full weapons suite, was previously slated to be delivered in 2013 and has been delayed by four years. Lockheed has reassigned engineers to work on the code.
Regarding the targeting system, DellaVedova said the EOTS will be able to transmit images to joint terminal attack controllers on the ground using the Link-16 communication transmitters when it enters service.
"It is the world’s first sensor to combine both air-to-ground and air-to-air infrared search and targeting capability in a very low observable (VLO) platform," he said. "EOTS allows the F-35 to conduct air-to-air and air-to-surface targeting missions while maintaining the F-35’s VLO profile – a capability that external podded systems cannot provide."
At the same time, DellaVedova acknowledged "a range of potential upgrades and enhancements" being considered for the system, including "Higher Definition Video, longer range target detection and identification, Video Data Link, and Infrared (IR) Marker and Pointer."
The Marine Corps plans to begin operational flights of the F-35B this year by using a limited version of the software known as 2B, which is expected to provide basic close air support and initial air-to-air and enhanced data-link capability for internal weapons including the AIM-120 Advanced Medium-Range Air-to-Air Missile, or AMRAAM, Joint Direct Attack Munition GPS-guided bomb, and the GBU-12 laser-guided bomb.
The Air Force plans to begin operational flights of the F-35A in 2016 with the Block 3i software. The Navy plans to begin operational flights of the F-35C in 2018 with the Block 3F software.
The F-35 is the Pentagon's most expensive weapons acquisitions program, estimated to cost a total of $398.6 billion for a total of 2,457 aircraft. That breaks down to an overall per-plane cost of $162 million, including research and development. Sustaining the aircraft over the next half a century is estimated to cost another $1 trillion.
Lawmakers last month approved about $8.8 billion for 38 F-35s — four more of the fifth-generation stealth fighters than the Pentagon requested.
(Story was updated to include link to latest Daily Beast article in the fourth paragraph.)