PROJECT VAL
Combat testing The Cannon-armed Sabreby John Henderson in collaboration with Lon Walter
It didn't take long for the pilots in Korea to realize the MiG-15 had more firepower than the F-86. In January 1951, Lt.Col. Bruce Hinton, 336th FIS Commander, briefed the 4th FM staff on the 21 days of combat recently flown out of Kimpo. His briefing included the admonishment THAT THE FIREPOWER OF THE F-86 IS NOT SUFFECIENTLY DESTRUCTIVE, AND SHOULD BE MODIFIED WITH A CALIBER HEAVY ENOUGH TO INSURE STRUCTURAL DAMAGE WITH A MINIMUM NUMBER OF HITS.
By September 1951, experienced Sabre pilots who had returned to the US brought with them the news that the F-86 needed heavier firepower. These included America's first three jet aces - Jim Jabara, Dick Becker, and Hoot Gibson; as well as WW2 aces John Meyer, Ralph Taylor, Billy Hovde, Glenn Eagleston, Bob Rankin, Jim Brooks, and Ben Emmert. Their reports also included other improvements that were needed, such as a more powerful engine and better gunsight - both of which were already being developed.At Headquarters USAF, Col. Benjamin O. Davis, Chief of the Fighter Branch, Directorate of Operations, was given the overall job of solving F-86 gunnery system problems. This would eventually lead to the replacement of the Al CM gunsight with the type A-4; and the M3 .50 caliber machine gun with a more potent weapon. The latter program was to become Project GUN-VAL.
Under Lt.Col. John England, Chief of the Fighter Gunnery Section, a Gun Evaluation (GUN-VAL) Committee was formed - which included many 4th FIG combat veterans. Among the evidence they reviewed was a paper written by Maj. Martin Johansen, which was supported by his gun camera film showing a MiG-15 absorbing multiple hits from .50 caliber bullets without any evidence of mortal damage to the pilot, airframe, or engine. A decision was made to proceed immediately with a test of two 20mm cannon capable of high rates of fire. These were to be installed in specially modified F-86s. When available, they were to be combat tested if the Korean War was still on-going. The Los Angeles Division of North American Aviation was contracted to modify 12 undelivered F-86s with rebuilt gun bays and four 20mm guns. These were to be tested by NM pilots before delivery to the USAF. 10 of the Sabres were to receive Mauser guns designed in Germany during WW2 but never installed in combat aircraft. Much later, the remaining 2 aircraft got Swiss-designed Oerlikon guns that had been successfully used in WW2. The Oerlikon installation eventually proved unsuitable; and after testing at Eglin AFB, that portion of GUN-VAL was terminated.
The Mauser cannon design had been captured from the Germans during the waning days of WW2, finding its way to the Springfield Armory, then to Ford Motor Company (FMC) for further development. For the GUNVAL Sabres, FMC provided NM with models designated as T-160 20mm cannon; a gas operated, electrically fired, belt fed, revolving cylinder gun with a cyclic rate of 1400 rounds per minute. The ten F-86s with T160 guns were re-designated F-86F-2, while the Oerlikon-equipped models received later, became F-86F-3.
Major structural modifications were required to enlarge the Sabre's gun bays to accomodate the 170 lb., 6 foot long cannon. The prototype guns received by NM from Ford required improvements to the gun feed and firing mechanisms before they could be used in the F-86. The NM Armament Department, headed by Paul Peterson (who designed the GUN-VAL installation) and engineer Jim Robertson, identified and corrected these problems.
As planned, NM test pilot George Welch flew the inflight firing tests. He pronounced the guns to be functionally reliable. But there were no tests of gun gas purging or ingestion at high altitude, a problem that would surface in Korea. All 10 F-86F-2s were delivered in 1952; 8 were destined for Korea, and 2 went to the Armament Center (AFAC) at Eglin AFB for engineering tests. Three USAF pilots flew firing tests at Edwards AFB in the Korea-bound aircraft, before the Sabres were flown to McClellan AFB for processing and shipment to the Far East.
The three pilots, Lt.Col. Don Rodewald (Air Research & Development Command), Maj. Ray Evans (APGC Detachment Commander), and Capt Lonnie Moore (APGC), were joined in Korea by Lt.Col. George Jones (Air Training Command, Nellis AFB) and Lt.Col. Clay Peterson (Tactical Air Command). Under the Aegis of APGC, these five pilots comprised the "dedicated" GUN-VAL pilot team in Korea. Additionally, pilots from the 4th FIG would also fly the GUN-VAL Sabres in Korea, including Lt.Col. Vermont Garrison, Maj. Bob Moore, Capt. Murray Winslow, l Lt Dan Druen, and l Lt Jerrold Bradley.
Once in Korea, the GUN-VAL detachment, including the aircraft, 5 pilots, a 12 man armament specialist team from Eglin, and 4 civilians, were hosted at K-14 by the 335th FIS, commanded by Lt.Col. Garrison. The 335th provided maintenance support and a secure flight line for the GUNVAL aircraft.
The combat program kicked off in January 1953 and ran for 16 weeks, ending in April. GUN-VAL airplanes were often flown in mixed flights with .50 caliber Sabres so as not to `advertise' the presence of the cannon-equipped F-86s. At other times, a flight of four cannon-armed Sabres was part of the overall mission schedule. It has been learned that Russian pilots who flew against the F-86 in Korea often derided the standard .50 caliber armament as "pea-shooters". But once the 20mm cannons were fired, a MiG pilot quickly realized that he was not up against a normal Sabre.
Although 8 GUN-VAL airplanes arrived in the Far East, one was held at Tsuiki AB REMCO center, and remained there until late January. At that time, one of the F-86F-2s was lost. Gun gas ingestion caused a compressor stall and flameout, resulting in Capt. Murray Winslow's ejection when he was unable to get an airstart. Winslow was rescued from the Yellow Sea. The Tsuiki bird replaced this first loss.
While the lethality of the T160/F-86 combination was proven early on, the problem of compressor stalls and flameouts caused by gun gas ingestion, particularily at high altitudes, was a serious problem. Combining data obtained from combat missions and 55 non-combat test flights over Inchon Bay, it was finally determined that the gun gas `envelope' that the airplane was flying through, was the culprit. Gun gas secondary explosions were occurring around and ahead of the aircraft nose. The resulting air-gas mixture, when ingested into the J47 burner cans created a compressor stall.
To reduce the size and effect of the gun gas envelope, an interim fix (unpopular with the pilots) was devised. It consisted of installing a switch in the cockpit that limited the number of guns which could be fired simultaineously. Pilots were instructed to fire all four guns ONLY below 35,000 ft., and two guns between 35 and 40,000. There was to be no firing above 40,000 ft.. Although the project aircraft were never grounded, there was a hiatus on air-to-air combat while the non-combat tests were flown. During this hiatus, six air-to-ground missions were flown to test the effectiveness of the 20mm guns.
Armed with the findings from Korea, NM's Paul Peterson returned to NM to `find a fix' that would allow firing all four guns above 30,000 ft. without fear of a flameout. Working in NM's Armament Lab, he found that a means of deflecting the gasses away from the critical intake area was needed. This was accomplished by installing a small horseshoe-shaped deflector in the gun troughs. This forced the gasses away from the aircraft, yet allowed the projectiles to exit without deflection. To assist Peterson, the Air Force sent one of the AFAC GUN-VAL airplanes to NAA to finalize the design of the deflectors. Test flights on this aircraft confirmed the effectiveness of the `fix'. There were no high altitude firing-induced engine problems.
As soon as possible, Peterson hand-carried deflector `kits' to Korea for installation on combat Sabres. There were no flameouts in the final month of GUN-VAL flights in Korea. Although a few secondary gun gas explosions were observed in front of the aircraft, there were no compressor stalls. By the end of April 1953, the Korea GUN-VAL test was completed and the remaining 6 aircraft were returned to the US. (A second GUN-VAL Sabre was lost in April when the J47 turbine wheel failed. Capt. Lonnie Moore ejected and was rescued.)
The final engineering to cure the gun gas ingestion problem continued long after GUN-VAL ended as a project. Eventually, a satisfactory design was patented that would allow the deflector to be adapted as required for other aircraft. Project GUN-VAL had a lasting and beneficial effect on the safety and effectiveness of future Air Force fighter aircraft. In production, the prototype T160 became the M39 cannon, and served many years in the F-86H, F-100, and F-101 fighters.
Project GUN-VAL Scoreboard
total flights ---------------------------------------368
combat missions -----------------------------------307
MiG-15s: fired upon -------------------------------41
hit -----------------------------------------22
destroyed-----------------------------------6
probables-----------------------------------4
damaged-----------------------------------13-18
pilot destroyed probable damaged
Maj. Evans 1 1 1
Lt.Col.Jones 2.5 1 1
Lt.Col. Peterson 1 1
Lt.Col. Rodewald 1
Capt. Moore 1.5 1
Lt.Col. Garrison 1 1
unknown 8-13;
totals 6 4 3-18
AIR ASIA F-86 PROGRAM
by Sid Yahn
The North American F-86F was the first jet fighter aircraft to undergo IRAN (Inspect and Repair As necessary) at the Air Asia facility located at Tainan Air Base, Taiwan. At the time I was flying Republic F-84Gs with the First Fighter Wing of the Chinese Air Force, which was also located at Tainan AB.In late 1955 or early 1956, Air Asia obtained the F-86 IRAN contract. However, they had no qualified jet pilots available to test fly the aircraft. Fortunately, I was given the opportunity to perform this task.
Air Asia was not a U.S. military organization. Therefore, U.S. Air Force authorization had to be obtained before I could fly these aircraft. On 27 December, 1956, I received the required authorization along with the additional AFSC of 4331 - Flight Test Maintenance Officer.
On 31 December 1956, the first F-86F, no. - 040, which had completed the IRAN program at Air Asia, was test flown. In total I flew sixty one Air Asia test flights. In addition I had the good fortune to fly the acceptance check flights for the Chinese Air Force. After an aircraft was accepted, it was then flown to the appropriate Chinese air base and assigned to a squadron.
I was active military, therefore no additional monetary compensation of any kind was received for these flights. Initially, a few flights proved to be `interesting'. But after several flame-out landings, an inflight fire, a high altitude canopy separation, etc., things began to smooth out.
As the program matured, and the workers moved down the learning curve, the Air Asia IRAN facility turned out an excellent product. It was not difficult to look at F-86s on a Chinese Air Base flight line and point out the aircraft that had been through the Air Asia IRAN facility. They looked like new aircraft, they smelled like new aircraft, and they flew like a new aircraft!
My association with the Air Asia IRAN program ended in the Spring of 1958 when they hired a former military jet pilot and I returned to the United States. At the time, few if anyone, could foresee the significant role that Air Asia IRAN activities would play during the period of the Vietnam conflict. I like to think the 1956 F-86 IRAN program helped to form the foundation of this larger Air Asia effort.
ONGOING RESTORATION -
WESTERN MUSEUM OF FLIGHTfrom David Hart
The Western Museum of Flight (WMOF), located at the Hawthorne Airport in Southern California, currently has four aircraft in the process of restoration, including this F-86F Sabre. Member David Hart sent us the information and a few photos that were taken at the Hawthorne Air Faire held on 13 August 2005.
The F-86F SabreJet was manufactured at the North American Aviation plant in Inglewood, California. This particular F-86F was number 122 in a series of 280 aircraft built for the Japanese Air Self Defense Force (JASDF), and was the last F-86 in the JASDF inventory. The Sabre was used in the retirement ceremonies that the JASDF had for their F-86's, 15 March 1982.The WMOF obtained the aircraft in November 1997 and is in the final stages of restoration. Presently, work is going on to eliminate corrosion and polish the metal skin. At the time of the Air Fair, the Sabre had no engine, but the cockpit instruments and switches had been fully restored.
When restoration is complete, the aircraft will be marked to replicate the F-86F that Jack Simpson flew as a member of the 35th Fighter Bomber Squadron based at Suwon AB, South Korea. Christened "Suitcase's Appleknocked", Simson flew most of his 61 combat missions in the aircraft.
MY LAST DAY AT WAR
by Dean Abbott
27 July 1953, Suwon AB, South Korea. I was one of four or five guys rounded up that morning in the 51st Group, and put aboard a Gooney Bird headed for Tsuiki, our rear echelon maintenance base in Japan. The mission was to bring back to Korea any and all the Sabres that the Tsuiki maintenance crews could make ready to fly.
The Armistice agreements were to go into effect at midnite of the 27th. And they were specific in that no additional equipment could be moved into Korea after that hour. If an airplane touched down in Korea by 2200 that night, they could stay. If not, they had to remain in Japan.The Tsuiki crews worked through the day. As they got a Sabre ready, a pilot was assigned and immediately flew the airplane to the nearest base in South Korea, K-2, Taegu AB, where he'd be logged in and certified by "referees" from the Armistice Commission. One after another, as the Sabres became available, that is what happened.
Finally, there were only two Sabres left. But now it was late in the evening and thunderstorms were forecast over K-2. The next to last one was finally ready and away it went in the dark. We shortly got word that the pilot had ejected over the Straits but had been picked up by a fishing boat. I had the very last bird and it became "ready" with just one hour left.
With a very dry throat, I climbed in, started the engine, and taxied to the active runway. Knowing that K-2 was in a valley surrounded by high hills, and that it was going to be poor weather with thunderstorms, and that I was going to have to make an ADF let-down and probably shoot a GCA landing, I was none too excited about the flight since I'd never done any of the above before!
Luckily for me, as I approached the runway, a jeep sped out in front of me and an airman jumped out and stopped me with crossed flashlights. I'd been spilling fuel and hydraulic fluid all the way down the taxiway. I gratefully shut down and called it a day.
Next morning, I called (with great difficulty) back to K-13 and talked to Col. Bob Baldwin, the Group Commander. I said, "Sir, I'm stuck here at Tsuiki with only my flying suit and no money. What do you suggest?" He replied, "Well Abbott, normally I'd suggest you go to the chaplin and ask for a loan. But as a combat aircrew, you're just like the aircraft - no longer welcome in Korea! Do the best you can and stand by for further orders." So that's exactly what I did for a week, living from pillar to post with my hard luck story.
Finally I ran into a guy I knew who got to ferry a T-33 (not a combat aircraft) back into Korea. I sweet-talked him into smuggling me back to K-13. I put my chute and helmet in his back seat and snuck out to a ditch alongside the taxiway. When he arrived, up went the canopy, in I climbed, down went the canopy and we were quickly off for K-13.
Upon landing at Suwon, up went the canopy and I slithered out and into another ditch. I snuck hack to my squadron thinking I'd beat the system and was proud of it. The squadron quickly brought me back to reality. I'd been in WONDERFUL Japan, where I could have remained for who knows how long. Now I was back in crappy Korea with no war to fight. Well, live and learn! Even Col. Baldwin thought that was pretty damn dumb as I recall.