by Colin Downes
Moore told me later that the helicopter was overhead as he hit the water and although the sea was fairly calm the water was very cold. Although he was wearing an immersion survival suit, when the helicopter lowered the strop to him after a few minutes in the water his hands were so cold he could not grasp the strop and put it around him. The winch man went down to hook him up and the ‘chopper’ took him to Paengyong-do. A light communication aircraft flew him back to base and after a check up at the base hospital he joined me for debriefing and the confirmation of his first Mig. With the camera gun evidence and me as a witness this was routine and we celebrated his first Mig and safe return that evening at the Officers’ Club. It was very reassuring that if one could make it to the coast the search and rescue facilities gave one a very good chance of survival. The Americans went to great lengths to retrieve downed pilots and we carried a homing beacon and an emergency UHF radio handset to contact searching aircraft. There was even a snatch pick-up retrieval system by which a C-47 would drop two poles with a line and harness. After attaching the harness to the line stretched between the poles, the pilot crouched down facing the rescue aircraft and the C-47 plucked him up with an arrester type hook. From 0 to 120 knots in about two seconds flat must have been quite some acceleration to experience, and better than a bungee jump. I witnessed a demonstration with no apparent ill effects to a brave volunteer when he landed, other than perhaps a higher pitch speaking tone. The territory over which we operated was mostly mountainous and I do not recall any of our pilots being rescued in this manner from the coastal strip, although I believe it was tried with some success with the fighter-bombers.
When Flight Lieutenant Graham Hulse was shot down the two fighter interceptor groups virtually stopped normal operations for two days to look for him. Hulse was an old friend who went to the US on an exchange posting before joining the 336th FIS on the 4th FIG at K-14. It appeared that Hulse was firing at a Mig and obtained visible strikes on the aircraft. As luck would have it he overran the Mig and in pulling up crossed in front of the aircraft that was in a climbing turn as it fired its guns. A 37 mm shell hit the F-86 by the right wing root and the wing folded back as the aircraft rolled over in a dive. Hulse’s wingman was firing at the Mig as Hulse passed in front of it and his camera gun film recorded the cannon strike on the F-86 as he continued to fire at the Mig before destroying it. In his preoccupation with the Mig he did not see if the F-86 crashed or whether Hulse was able to eject. The 4th FIG felt the loss keenly and after making a great effort to find Hulse, awarded him a posthumous half share of the destroyed Mig-15. My own view is that he was in the aircraft when it crashed, but we never established his fate and his name did not appear on any POW lists.
How now! A rat? An interesting speculation of Moore’s engine failure was whether his engine had failed because of the ingestion of some debris from the disintegrating Mig engine or whether his engine had exceeded its limitations through the use of a ‘rat’ or a ‘mouse’ attached to the jet-pipe. A ‘rat’ was a small steel plate about six inches long by two inches wide and curved to fit the contour of the inside of the end of the jet-pipe. A ‘mouse’ was half the size of a ‘rat’ with half the effect. These plates reduced the effective diameter of the jet-pipe efflux increasing the jet-pipe temperature and thereby increasing the thrust. We flew the F-86 at maximum power often exceeding the laid down maximum jet-pipe temperatures for a short period. Some aircraft due for engine overhaul would be down on percentage power and hence the use of this device to make up the shortfall. This was especially so if flying an earlier F-86E with an F-86F. After I complained to Lonnie Moore that I had difficulty staying with him when assigned an old aircraft, he introduced me to the practice of the rodents. Although officially frowned upon and needing the cooperation of an understanding crew chief, a lot of these rodents went flying on sweeps. They were very useful if applied judiciously to get that extra bit of thrust. Chasing a Mig at high altitude with only a fractional overtaking Mach number took time involving a considerable distance covered towards the out of bounds areas that was very frustrating, and we needed all the help we could get. No doubt at times they caused excessive jet-pipe temperatures and I only used one occasionally on an aircraft down on percentage power. I had no desire to risk a prolonged stay in the Antung ‘Hilton’ just to get a Mig-15, but others felt differently. On this occasion I did not see anything enter Moore’s intake but it would only need a small piece of metal to throw a turbine blade and chew its way down the compressor. However, I did wonder if it was a question of the biter bit; with Moore being his own victim when in trying to catch the Mig to score his first claim, his turbine threw a blade as a result of exceeding the maximum jet-pipe temperature. If Moore knew he did not say, and although it may have been only a wee mouse that gang aft a-gley, in this instance I smell a rat!
The squadron had both the F-86E and the F-86F, with a GE-J47-13 engine in the ‘E’ model producing 5,200 lb of static thrust and a GE-J47-27 engine in the ‘F’ model producing 5,910 lb of static thrust. This gave the ‘F’ model a slightly better performance in speed, climb and altitude. When the first F-86Fs arrived on the squadron the ‘shooters’ took the ‘F’ models and with their wingmen still flying the older ‘E’ models they had problems in supporting their leaders. It did not occur to some ‘leaders’ to consider the advantages of keeping their wingmen with them the whole time even to the extent of reversing the assignment. If they did, then the consideration of the advantage of the ‘F’ model over the ‘E’ model in shooting down a Mig-15 put paid to the idea. It certainly did not appeal to those in the habit of breaking away from the flight during sweeps in a ‘lone wolf’ pursuit of the Mig-15s. The obvious answer was to fly the same models in the flight as the differences between the two types of F-86 were significant under combat conditions with the Mig-15. The most important difference of the two models for any would-be ‘ace’ was the installation of the A-4 radar gun sight in the ‘F’ model. The A-1 radar gun sight in the ‘E’ model was not only very unpredictable but also very unreliable.
On every mission the standard procedure was to level off at 15,000 feet during the climb to test fire the guns, this also allowed the engine oil that was scavenged during flight to drain forward. With the aircraft trimmed to fly straight and level we fired the guns, and frequently when flying an F-86E with the A-1 sight it went out never to reappear. The harmonization of the six Browning machine-guns bore sighted them for the bullets to converge at 1,000 feet. The first ten rounds in each gun were tracer rounds and a sighting dot made on the windscreen with a grease pencil where the rounds were seen to converge provided a reference mark for aiming when the sight failed. This allowed for a non-deflection shot from astern or for a fly through deflection shot, often referred to as ‘Kentucky Windage’. The F-86F had an A-4 sight that was a great improvement, both in tracking and ranging the target, over the A-1 sight when it worked, and it was also very much more reliable. Sometimes the radar ranging did not work or it hunted in and out, but if the sight’s two mil pipper was visible a useful rule of thumb was that it filled the Mig-15 jet-pipe at 1,000 feet.
A major modification to the F-86F provided a 6 inch by 3 inch leading edge extension to the wing. This removed the automatic leading edge slat with a fixed leading edge giving six more inches at the wing root and three inches at the wing tip. A later modification added a boundary layer fence at mid-wing five inches high. All of which gave additional speed with improved handling and increased the stalling speed by around ten knots, with the F-86E technically stalling at 111 knots and the F-86F at 125 knots. We therefore had three types of F-86s Sabres on the squadron in 1953 and we were very glad when our F-86Es went to No. 2 Squadron, South African Air Force, on the 18th FBW. These F-86s replaced their P-51 Mustangs, so they must have been very happy to receive the jets for their ground attack missions.
Air combat between the F-86 and the Mig-15 at high altitudes demonstrated that the F-86 armament of six Browning 0.5 inch machine-gu
ns was inadequate for a high probability kill factor against the Mig-15, and indicated the need for a heavier cannon armament with a high rate of fire. All our F-86Fs had the modified hard wing and in June 1953 we received six F-86Fs equipped with four M-39 20 mm cannon installed in place of the six Browning guns at the nose intake. The M-39 cannon based on the design of the German Mauser MG-213 30 mm cannon had a revolver type ammunition feed for a high rate of fire, with the ammunition fired electronically. We were the only squadron on the 4th FIG to be so equipped as part of the GUNVAL operational armament trials. The four cannon had a rate of fire similar to that of the Browning machine-gun of around 1,100 to 1,200 rounds per minute. The Browning was a very reliable gun and the 0.5 inch calibre bullet was more accurate at a longer range than the 20 mm M-39 cannon shell; but even with armour piercing, incendiary and high explosive rounds the weight of fire from the Browning guns could not inflict sufficient damage to shoot down a Mig-15, or even slow it down for a kill, at altitudes above 30,000 feet. At altitudes over 40,000 feet, despite gun camera film clearly showing strikes hitting the Mig-15, the rarefied air would not provide sufficient oxygen to support combustion. Post-war studies by the USAF showed that about two-thirds of the Mig-15s attacked at high altitudes escaped destruction. During these attacks around two-thirds of the armament load of 1,600 rounds carried by the F-86 was expended over a firing time of ten seconds, even with the six 0.5 inch machine-guns point harmonized at 1,000 feet and the guns sighted, ranged and tracked with a radar gun sight. On the other hand hits from the Mig-15’s two 23 mm cannon with a rate of fire of around 800 rounds per minute; or a single hit from the 37 mm cannon, with an even slower rate of fire of around 300 – 400 rounds per minute, could cause massive, and probably fatal, damage to the F-86.
‘GUNVAL’, the code name for the four 20 mm cannon gun evaluation trials on the F-86F, were not a success. When the four cannon were fired at altitudes above 30,000 feet the muzzle blast from the four cannon blanked the air intake creating an engine compressor stall, resulting in an engine flame-out. To overcome this it was necessary to fire the cannon in pairs, selecting the top pair followed by the lower pair; and to fire in short bursts. This not only halved the anticipated impact of the weight of fire of the 20 mm shells, but increased the kill probability firing time. In addition, the accuracy and range of the 20 mm shell was inferior to that of the 50 calibre bullet of the Browning machine-gun. Consequently, although the GUNVAL F-86s claimed six Mig-15 kills and in the process lost two aircraft, as the majority of Mig-15 kills resulted from an astern attack at close range many of the ‘Old Hands’ preferred to use the standard armament of six Browning machine-guns. I never did fly one of the 20 mm cannon aircraft but I did fly on one of the first combat trial missions. I flew as wingman to our squadron executive officer, Major Vermont Garrison, who later became the squadron commander. I had a standard F-86F and at 45,000 feet on a sweep south of the Yalu we spotted four Migs high above us. Garrison climbed in pursuit at full power after the Migs heading north. We crept up to nearly 50,000 feet but the Migs, although still strung out, remained above us and out of range. Although at maximum power I fell behind and below Garrison, and this was my first experience of the extent of the advantage the Mig-15 had over the F-86 in terms of climb and altitude capability, even against the improved ‘F’ model. We could never operate above 48,000 feet flying the ‘E’ model. We continued to follow the Migs as they crossed the Yalu into Manchuria. Our second pair had fallen well behind in the chase and as we continued after the Migs the number four called ‘bingo’. Garrison told them to return to base and we continued after the Migs. It was obvious that at 50,000 feet with our marginal closing speed any combat was unlikely unless the Migs turned to fight. My fuel was down to a ‘bingo’ call of 1,500 lb and I suggested to Garrison that we fire towards the Migs in the hope that the tracer rounds loaded in his 20 mm cannon and in my 0.5 machine-guns would persuade them to turn. Garrison agreed and with the Migs still well above us and out of range, I eased the nose of my aircraft up slightly to get an upward line towards the Migs and fired my guns. The aircraft stalled but the engine kept running and as my nose dropped down I saw Garrison above me go into a spin. The Migs kept on their way, which was probably fortunate as I followed Garrison down, calling to him but getting no response. He continued in a spin and I kept calling him to recover. At around 25,000 feet he made an incoherent response and at around 20,000 feet the aircraft came out of the spin. The F-86 continued in a steep dive and eventually came out of the dive at around 10,000 feet. As the mountain tops were over 6,000 feet this was rather close for comfort. I continued to call to Garrison but he remained incoherent and disorientated due to severe anoxia. I continuously called attitude, heading and altitude to him all the way back to K-14, where I called for an emergency landing and talked him down to the runway before overshooting for my landing. Garrison stopped at the end of the runway and an ambulance took him to the hospital.
Garrison told me later that before firing his cannon in the direction of the Migs he saw 50,000 feet on the altimeter. When he fired the four 20 mm cannon the aircraft stalled and there was a bang as the engine stalled with an explosive decompression of the pressurization system that filled the cockpit with white cloud. The effect of the decompression produced intense hypoxia. He became unconsciousness as his 11,000 feet cockpit altitude rose instantly to his aircraft altitude of 50,000 feet. The very efficient pressure demand oxygen system in the F-86 saved his life. He did not recollect the aircraft spinning or the recovery from the spin, and it is likely that the F-86 recovered from the spin by itself when it reached denser air. When he partially recovered his senses he realized the aircraft was diving steeply and while pulling the F-86 out of its dive he realized that he had no engine power. He must have done the right things for the engine started up when he resumed level flight. My instructions filtered through to him despite a blinding headache, dizziness and difficulty in focusing his eyes. By an intense concentration of survival he managed to handle the very difficult situation until at the end of the runway after stopping the aircraft he collapsed. It was a good thing there were no Migs around and the weather was clear otherwise the flight would have had a different ending. Although physiologically Garrison’s age may have made him more vulnerable to the effects of hypoxia than a younger and fitter man, his great experience pulled him through. It was a couple of days before he returned to normal flight duties still suffering from headaches. To my recollection, despite the limitations imposed on firing the cannon in pairs, the squadron claimed several Mig-15s shot down, but one way and another none of the six aircraft survived to the cease-fire. I reported the result of the cannon trials to the Air Ministry in July 1953, but when I returned to Fighter Command early in 1954 I found that the Hunter, due to enter service in that year, suffered the same problem of an engine compressor stall when firing the four 30 mm Aden cannon at altitude. It appeared to me that a valuable year was lost in solving one of the many armament problems associated with the early Hunters. Interestingly, the Mig-15 did not appear to suffer from the same problem of intake blanking when firing the 37 mm and two 23 mm cannon. This was because the Mig-15 engine had a centrifugal compressor based on the Rolls Royce Nene engine given to the Soviet Union, as against the axial flow compressors in the General Electric J47-27 engine in the F-86 Sabre and the Rolls Royce Avon engine in the Hawker Hunter.
One mission for which there would be no pilots over the rank of captain and very few of those, was the alert readiness detail. Every day from dawn to dusk two squadrons positioned a flight with back-up aircraft on the alert strip at the east end of the runway. One flight would be on readiness with the pilots in their cockpits, and the other flight would be on standby with the ground crews near the aircraft and the pilots in the dispersal hut. The flights rotated hourly and were ready to scramble to intercept hostile aircraft that never came – at least by day. If a flight scrambled it would be to provide a ‘rescap’ for aircraft with an emergency over No
rth Korea. The major concern was scrambling in bad weather conditions with little confidence in the local radar. The navigation aids were an ADF beacon on the airfield and one on the approach from the west. The use of a radio compass while flying in or near thunderstorms was unreliable as the needle would often turn towards the thunderheads. K-14 had its GCA radar positioned for the flat approach from the west and, as with the surveillance radar, it was often operated by grounded pilots with little controlling experience. The communists complicated the bad weather letdowns by citing a decoy ADF beacon on the approach frequency in the Haeju peninsula to confuse fighters returning to base.
‘Flying in on a wing and a prayer’ was a Second World War song that I recalled while leading a flight on readiness during the monsoon season. Bad weather had closed the airfield for normal operations with low cloud and heavy rain. I sat in the cockpit watching the rain thinking that with our inadequate navigational facilities we would not return to K-14 if scrambled. My reverie was shattered as Operations scrambled us on an unidentified target at an undetermined altitude to the north. We climbed through the overcast breaking into clear sky at around 30,000 feet. This was the good part as during the monsoon the cumulonimbus tops could exceed 45,000 feet. The bad part was four-day fighters not equipped with airborne interception radar, scrambled to intercept an unknown target in cloud, with the weather at base below minimums and no suitable diversions. Instructions came to orbit north of the front line and the operations radar could only maintain contact with us by use of our IFF. After twenty minutes spent enjoying the sunshine with no interception control forthcoming, instructions came to return to base. The weather conditions were the same as on take-off with no improvements at diversion airfields. On the premise, better the devil you know, I informed the tower we would position for a straight letdown into the GCA radar, and should the weather force us to overshoot we would try any available diversion and if this failed our letdown would be via our ejection seats. Assistance from radar and cross fixes on our ADFs positioned us for a straight descent from the west. The second pair elected to remain in tight close formation for the letdown and approach. Although the junior squadron pilots had little experience of weather flying before arriving in Korea, they were not lacking in their ability to hold tight formation. The approach from the west was over flat paddy fields, whereas from the east the approach was over hills, and close to the airfield in line with the runway was a small hill, 300 feet high, named ‘Bust-your-Ass’ mountain. The line-up on the runway from the west had to be precise because a few miles south-west of the airfield was a sharply pointed hill 1,500 feet high that we graphically referred to as ‘The Witch’s Tit’! The descent was through thick cloud with heavy rain and on reaching 2,000 feet we dropped landing gear and flap, and fed into the GCA. We passed our safety height without contact and at 200 feet we started to break out of cloud in heavy rain. I got a glimpse of the runway lead-in lights as we broke cloud and at 100 feet I could make out the runway and called contact, telling the second pair to ease back for the landing. Owing to the downwind touchdown in the wet we nearly aquaplaned off the end of the runway, but all four F-86s landed on the runway undamaged. It was the best GCA I was to experience in Korea under the worst flying conditions. We never did find out the reason for the scramble. Quite likely someone misread their CRTs radar paint or picked up a met balloon and hit the panic button. The result could certainly have been worse with a score of 0 – 4 in favour of the communists.
