The USAF has been trying to kill the A-10 for as long as the Warthog has been in service. Part of this effort saw the A-10's huge GAU-8 Avenger 30mm cannon shrunk down into a pod that could be carried by sexier fighters, primarily the F-16. The results of which were far from impressive...
By the middle of the 1980s the USAF was obsessed with getting rid of the A-10 and getting something faster to replace it. The A-7F Strikefighter was one proposed solution among a few others that gained traction, although the biggest effort revolved around different concepts to modify the F-16 in order to make it more capable of battlefield interdiction and close air support. Parts of this initiative included installing some wildly advanced avionics for the time period, as well as fitting an awkwardly powerful cannon to the lean jet.
The cannon itself was designated the GAU-13, and the podded system it would be carried in was designated the GPU-5. The USAF program that developed it was called "Pave Claw" and General Dynamics, the cannon's manufacturer, marketed the system "GEPOD30."
The entire gun and magazine was contained in fat external stores pod made to be carried on tactical fighter aircraft. The GAU-13 cannon itself was a shortened pneumatic-powered, four-barreled version of the Warthog's giant seven barreled GAU-8 Avenger cannon. Because of its modular format, overall size and weight limitations, the GPU-5 had a rate of fire of about half that of the GAU-8, or about 2,400 rounds per minute. Still, this smaller podded version of the Avenger packed one hell of a punch as it slung the same coke-bottled size 30X173mm ammunition that its bigger brother did, including depleting uranium penetrator rounds. All ammunition was carried internally in the pod, of which could hold 353 rounds.
Although the GAU-13 cannon was not specifically designed for the F-16, and A-7, F-15E and even F-5s could carry the GPU-5 pod, in it the USAF saw a particular opportunity to give the F-16 the A-10's claim to fame and its main supporters biggest argument as to why it should continue to stay in the inventory, a 30mm gun that can shred even a main battle tanks' heavy armor.
Out of the jumble of initiatives that were focused as seeing the F-16 take the A-10's tank busting and troop supporting gig, there were a few loosely related proof of concept and test and evaluation programs that standout. Although their exact relationship remains muddy, the cause and effect of the failure of these programs would result in the A-10 surviving in USAF inventory for decades to follow, as well as helping prove game changing technologies that would only mature years later.
The most advanced of these initiatives was one that saw the F-16 gain a 30mm cannon and a ton of new avionics. This aircraft was to be named the A-16. The A-16's modifications included an elaborate confromally mounted "Falcon Eye" FLIR and targeting system. A test aircraft was outfitted with this system which included twin sensor balls on the F-16's nose and twin targeting systems blended into the aircraft's wing roots. Also, the "Cat's Eyes" helmet mounted sight was tested with the FLIR system.
Something of between a crude version of the F-35's DAS and the Apache's monocle sighting system, "Cat's Eyes" and "Falcon Eyes" allows a pilot to see the what the forward hemisphere FLIR sees while looking in any direction but directly down. The system also allowed for some traditional HUD symbology to be projected onto the helmet's prism viewing system for enhanced sistuational awareness,. Also, the system allowed for easy visual hand-off of targets, even at night as laser designated or coordinate based targets could be seen visually through the helmet.
Radar upgrades and software upgrades were also part of the A-16 project, including an advanced "target hand-off" system that could data-link a ground targets to A-16s with relative ease. A 30mm cannon was designed for the aircraft, along with a strengthened wing structure to support it, but it was deemed to be too hot for the tightly packed electronics in the F-16 and would set fire to and/or singe the left side of the fuselage when fired.
The whole advanced A-16 concept was seen by many as self-defeating as it was growing the F-16 into a heavier more expensive jet than it was designed to be, and its advanced components were at the time fairly clunky. In the end the A-16 and the whole permanently installed "Falcon Eyes/Cat's Eyes" system was abandoned after testing was completed, as the USAF's more modular and less advanced pod-based LANTIRN system was chosen for the F-16C Block 40, albeit the Block 40 was more focused on deep strike and night operations than CAS.
The most mature of the pro-F-16/anti-A-10 initiatives was the rapid fielding of the GEPOD30 onto lightly modified F-16As from the 174th TFW based in upstate New York. The 174th had flown A-10s previously to the F-16 and in 1988 they were tapped to be the first close air support-oriented F-16 unit. Their aircraft were Block 10 F-16As that were modified in a few ways to reflect their new mission. These changes included a green camouflage "European One" paint scheme, some minor avionics tweaks and the rapid fielding of the GEPOD30 gun pod.
The whole concept was farily austere to say the least, and within a year or so of the 174th getting their stripped down "F/A-16s," Nellis AFB and Shaw AFB began running a pair of incremental test programs to help evolve the F-16 into a CAS aircraft further. Both Shaw's and Nellis's jets were painted green and were newer than the 174th's F/A-16s, they were also given better avionics to play with.
Different configurations were flown, with Shaw's F-16C based test aircraft doing more of the advanced avionics work and Nellis's more numerous but less technologically equipped fleet doing tactics development work. These configurations including a stripped down "Falcon Eye" system with a helmet mounted sight, albeit without all the targeting modifications seen on the A-16. Other configurations included the installation of a terrain avoidance system, GPS, and a more mature targeting hand-off system than the earlier A-16 had. The Nellis jets featured Pave Penny pods and more minor upgrades, some of which were rumored to have some light armor installed around the cockpit area.
While this "second coming" of the F-16 as a CAS platform for the USAF, in as little as a half decade no less, was in full swing, tensions erupted in the Gulf and Desert Shield would quickly turn into Desert Storm. The true test of the F/A-16 concept, and the GPU-5 gun pod for that matter, would be actual combat and the 174th TFW was rushed overseas to prove themselves.
During what would be a turning point in the way the world looks at air power, the F/A-16s set out to prove their worth. The idea was to unleash continuous streams of precision fire from their big 30mm gun pods onto Saddam's armor and material and to finally prove that the faster, shorter legged and more nimble F-16 could indeed become a low-level gunfighter like the A-10.
The results were less than desirable. In fact, they were horrible. Within the first 48 hours of continuous combat operations the GEPOD30s were proven to be totally unable to satisfy their intended mission. Precision fire was almost impossible with the setup as the F-16s software had not been adequately modified for aiming, and the vibration was so bad when the gun was fired that software tweaks probably would have made little difference anyway and it wreaked havoc on the F-16's sensitive electronics and mechanical components.
The reality is that the system was so ill-suited to the aircraft that just firing the gun multiple times would tweak the pylon it is attached to and thus it would become skewed far off zero. Not to mention that in comparison to the low and slower flying A-10, in actual combat the F-16's high speed made it hard to get a proper sight picture to aim during long strafing runs. Apparently maintainers and pilots had warned that the gun was ill-suited for the light fighter long before the deployment, but their mission was to try and make it work.
After the first few mission evolutions during the opening of Desert Storm, it was clear that the GPU-5 was an area suppression weapon at best, and the 174th unbolted the heavy gun pods from their jet's and went back to using cluster and general purpose bombs on targets. A practice they would continue to practice as they patrolled their kill boxes throughout the war.
In the end the USAF had to swallow the fact that a big tank cracking 30mm cannon was just too much for the diminutive F-16, and this, combined with some other legislative and DoD wrangling, kept the A-10 in service for another 20 years as America's top Close Air Support jet.
As a side note, almost all the GPU-5 pods and the GAU-13 cannons that were mounted inside them were assumed by the USMC. They tested mounting one on a container that was strapped down on the deck of one of the Navy's Landing Craft Air Cushion (LCAC). The idea was that an LCAC could literally hose a beach down with heavy 30mm cannon fire as the Marines came ashore. Each LCAC could theoretically carry up to four of the systems and it was known as the Gun Platform Air Cushion or "GPAC."
It is unclear if the system ever actually became operational, but one can only imagine how effective it could have been at providing suppressing fire for landing Marines. I would imagine just the long throaty cries of "bbbuuuurrrrpppp" would keep the enemy in their foxholes long enough for the individual Marines to start plying their trade.
Images via DoD, Lockheed, General Dynamics, Public Domain.
Tyler Rogoway is a defense journalist and photographer that maintains the website Foxtrot Alpha for Jalopnik.com You can reach Tyler with story ideas or direct comments regarding this or any other defense topic via the email address Tyler@Jalopnik.com