18th Fighter-Bomber Wing in Korea

Doublemint - a Sure Cure for Engine Roughness

September 1948 .. and the thought about that long, long swim to shore...

Following my arrival in Japan, in mid-July, 1948, I was promptly assigned to the 35th Fighter Group at Johnson Field, thirty miles northwest of Tokyo. There I joined the 40th Fighter Squadron and felt extremely fortunate to be stationed at one of the 'showplaces' of the Air Force in Japan.

After just a couple of short, local area flights in the P-51 to familiarize myself with the beautiful Japanese countryside, I was promptly assigned the task of ferrying an older P-51 Mustang to the 18th Fighter Group at Clark Field, in the Philippine Islands. The 18th was then in the process of converting from P-47s to '51s, and the Mustangs had been pulled out of "mothballs" in Japan for the transfer. They were in reasonably good mechanical condition, but had been stored in the humid Japanese climate since the War ended in 1945. A great deal of corrosion had taken place. The mechanics had cleaned them up as best they could, but I was to find that they had missed a spot or two on the ship that I was to fly on the long, fifteen hundred mile overwater flight to the Philippine Islands.

We were taking twelve Mustangs on that ferry flight, escorted by a lead B-26 with a Navigator aboard. Our course was plotted to Itami, on the southern Japanese island of Kyushu, then across the sparse island chain to the little island of Okinawa and, finally, the long 600 mile overwater leg direct to the Philippine Island of Luzon. Clark Field lay about 200 miles beyond the northern tip of Luzon ...across thick, uninhabited, mountainous tropical jungle.

The weather was clear for our take-off from Johnson Field and we had a beautiful view of Mount Fujiyama as we passed nearby. Shortly thereafter, however, I noticed that my coolant temperature gauge was flickering, then rising to the high side of the dial ...into the Redline.

Loss of coolant in a liquid-cooled engine, such as the big Rolls Royce Merlin, could mean a sudden engine freeze-up after twenty minutes or less. Consequently, a coolant over-temperature condition was not to be treated lightly.

I throttled back, but the needle remained on the high peg, so I called the Flight Leader by radio, to tell him that I would have to return to Johnson Field to have the coolant problem checked out. I suspected corrosion of the electrical connector to the instrument ... but I couldn't be sure, and I didn't want to take the chance, for fear that it could be the real thing: lost coolant.

A quick check by the Johnson Field mechanic bore out the corroded electrical connection theory and, after an hour, I was refueled and off again, by myself, to meet the rest of the flight at Itami, where we all spent the night. Early the following morning we took off on the first overwater leg, toward Okinawa.

Single-engine fighter planes produce a built-in psychological syndrome: ‘automatic overwater engine roughness’. It makes it's presence known the instant you cross the beach outbound. The prospect of bail-out or a ditching far out at sea is unnerving, to say the least, and I'd had little or no previous overwater experience to prepare me psychologically for the broad expanses of sea which I was about to encounter. Even though I could see an occasional small island far off in the distance, or far to the side of our course, I was very apprehensive.

When over the ocean, a single-engine pilot pays close attention to the accuracy of his navigation, and knows at all times whether it is closer to glide to the island he last passed over, or to the one out ahead. He also keeps a very close watch on his engine instruments, for the first sign of trouble and listens very carefully to the constant, steady "purr" of his engine. I expected my coolant gauge to act up again as soon as we left the island of Kyushu, but it didn't ...it waited until we'd passed the last island in the Japanese chain, and we had a three-hundred mile stretch of open water to Okinawa before it flicked thru the Redline and up against the peg ...just as it had done on the previous day.

This time I was fairly certain what the problem was, and it was by then closer to go on to Okinawa than to return to Itami for repairs, so I ignored the instrument ...or I tried to ignore it, and continued on. After a nerve-wracking one and one-half hours, during which time I was sure (in my mind, at least) that the engine was running rougher, and rougher, we finally landed at the almost deserted, former wartime air base at Kadena, Okinawa.

Once again the mechanics checked the engine, and scraped a bit more corrosion from the electrical plug to the Coolant gauge. On run-up it again showed the proper, cool and stable indication. I personally checked it, and the level of the coolant fluid, carefully. The next leg of the flight was to be a long, 600 miles over open water ...too long a stretch to be worrying about a hot coolant gauge.

The weather turned sour over the Philippines for the next few days, thanks to a typhoon rolling across the South China Sea, and we became thoroughly bored sitting on the ground at the the desolate Kadena airstrip. The food was terrible, the GI cots uncomfortable and, despite mosquito netting all 'round, the mosquitoes were eating us alive each night. We talked ourselves (and the weather forecaster) into believing that the Clark Field weather was up to 1000 feet for the first time in three days, and improving enough for us to be on our way.

We took off from Okinawa on the next day and, after passing through a thin layer of clouds, were on top and in clear blue sky at 10,000 feet. My engine seemed to run smoothly as long as we were over the clouds, and I could not see the broad expanse of ocean below, but about an hour later, when 300 miles out to sea, the clouds broke clear, and my imagination again began to play tricks on me.

About the same time, coincidentally, I had put a piece of chewing gum in my mouth ...to help keep my ears clear during climbs and descents. With the sight of the wide expanse of open sea, stretching endlessly in all directions, I suddenly sensed a rythmic surging sound that didn't seem normal for the big Merlin engine. And, when I checked my engine instruments, the coolant gauge needle was once again pegged against the high Redline!

The engine continued to surge, and the longer I stared at the red line on the coolant gauge, the more apprehensive I became. I knew what the problem was ..there could be no doubt about it, just a faulty electrical connection at the instrument; the engine really was not overheating ...but I was more than three hundred long, wet miles from the nearest dry land, and the sound of the surging engine definitely resembled a potential problem in the making.

The more I thought about it, the faster I found myself chewing my Double-Mint ...faster and faster, and the engine surge seemed to increase its surge tempo accordingly. Finally, realizing that my problem had to be psychological, rather than mechanical, I took the wad of Double-Mint gum from my mouth and carefully pressed it over the entire glass face of the coolant gauge, so I could no longer see the position of the needle.

Instantly, the engine seemed to smoothe out!

Only then did it become obvious to me that the chewing, the opening and closing of my jaws, had been rythmically changing the position of my earphones inside my cloth flying helmet ...allowing a varying engine sound to enter with each movement of the jaws. The "surging" engine sounds, coupled with the high-pegged coolant indicator ...and the natural, expected "overwater roughness" of the engine, promptly disappeared, and I could sit back and relax for the remainder of the long flight to Luzon.

The engine's imaginary roughness was gone, but we were still faced with the ominous weather build-ups all along the north coast of Luzon. The center of the typhoon had passed and was sitting a couple hundred miles north, near Formosa, but the thunderstorms trailing the eye of the storm were higher than the maximum ceiling of our P-51 Mustangs. As we approached the coastal build-ups, we first dropped down to see if we could fly beneath the heavy weather; no way! The scud clouds were right down in the tops of the jungle-covered hills.

A radio report from Clark Field indicated that they had a 1000 foot ceiling, so we turned south to parallel the East coast, hoping we'd find a break high enough to sneak thru a valley in the mountain range which ran along the entire east coast of the island. We didn't dare try to penetrate the clouds, to go into Clark on instruments, because there were no radio aids to assist our letdown to the field. It had to be a visual approach, or nothing. It turned out to be "nothing".

After searching the entire coast, just skimming the waves, we were unable to find a clear valley opening and had to give up and set a return course for Okinawa ...by that time, an 800 mile direct line over the open water, with not a single island along the way! A fighter pilot hates to ever admit that a bomber crew has capabilities that he does not. We always claimed, for instance, that we could drop our own bombs, so there was no need to carry a Bombardier; we handled our own radios, so there was no need for a Radioman; we fired our own machine guns, so there was no need for a Gunner; and we had always done our own navigating, such as it was, so there was no need for a Navigator to be aboard.

On this trip, however, we had to swallow our pride and admit that we were damned glad to have a fully-qualified, professional Navigator aboard our B-26 lead ship. He was our savior that day. Without him plotting each angle and turn of our meandering trip down the coast of Luzon, we would not have had the slightest idea how to find the little speck of land in the middle of the Pacific Ocean called "Okinawa". As it was, we turned northeast and droned on and on, until finally we could see the island right off our nose, in the clear. Most of us had less than an hour of fuel remaining when we landed ...very tired, but thankful for the services of a real "pro".

After another day on Okinawa, we were able to make Clark Field without incident, in clear blue weather. The people of the 18th Fighter-Bomber Group at Clark Field were glad to see us. We'd had them worried the previous day. They had sent a similar flight ferrying P-47s toward Guam, by way of Formosa just a couple days before, and seven planes were lost while trying to sneak under the storm clouds of the same weather front we had run into, trying to reach the airstrip at Taipeh, Formosa. Three good pilots had been killed.

I remembered that overwater roughness episode for the rest of my flying career, because I have always chewed gum to help keep the air pressure in my ears equalized during rapid climbs and descents. Whenever I thought an engine sounded like it was surging, I would just quit chewing momentarily ...the "roughness" usually went away.

Duane E. 'Bud' Biteman,
Lt. Col, USAF, Ret
‘...One of those Old, Bold Fighter Pilots’
© restricted usage