WE WERE skimming the tops of clouds at 37,000 feet when I decided to start our letdown into the target, 10 minutes earlier than planned. We armed our .50-caliber machine guns in preparation for action.

It was Oct. 8, 1950, early in the Korean War, and two of us -- myself and my wingman, Al Diefendorf -- were on a mission over North Korea. Only later did we learn that we had strayed and were, in fact, a few miles inside the Soviet Union.

At 10,000 feet I spotted a small hole through the clouds. We dropped our F-80s in tight circles through the opening and found ourselves above a broad river valley with mountains on each side. Following the river, I proceeded southeast, a heading which I thought would bring us directly to the coastline and well away from the Chinese and Soviet borders.

In the days preceding this mission, signs of the enemy had been scarce, so I was surprised when I saw flashes of anti-aircraft fire from the top of a two-story building in a small town about 500 yards off our right wing. I alerted Diefendorf.

About 20 seconds later I spotted a truck heading west on a dirt road. "Let's go in and get it," Dief said. An instant later, he shouted, "Look at the airfield, it's loaded!"

It was the kind of target that fighter pilots dream about. Parked in two rows were about 20 aircraft of the P-39 or P-63 type. Thousands of them were built and flown by Americans in World War II, and some were sent to our Soviet ally. Those below us had large red stars surrounded by a narrow white border painted on the side of their dark brown fuselages.

I had only seconds to make a decision. At our speed, the airfield would soon pass beneath us unless I positioned us for an attack. We were also nearing minimum fuel. Our low altitude and the low hanging clouds prevented me from seeing more than a mile or two in any direction. Even if I could have identified distinctive terrain features, it was unlikely I could have related them to the crude maps I carried on the mission.

What made me decide to attack? First, we had had intelligence reports of an expected movement of aircraft down the northeast coast of Korea; second, the planes' markings were nearly identical to those used by the North Koreans; third, I had used caution in my dead-reckoning navigation so as to hit the coast well south of Soviet borders. More important, they had shot at us first.

Two uncertainties bothered me. First, P-39 type aircraft had never been seen before in North Korea, and secondly, I was not certain where we were. Our target was an airfield at Chongjin on the far northeast coast of the Korean Peninsula, some 430 miles north-northeast of our base at Taegu Air Field in South Korea and only 40 miles south of the Chinese border and 60 miles southwest of the Soviet border. The airfield below didn't match the description of the one at Chongjin, which was reported to have a hard surface.

But I did not hesitate. We went in for the attack.

In our intelligence debriefing later, we claimed one aircraft destroyed and two damaged. We were conservative. Several months later an intelligence officer assigned to Far East Air Force Headquarters told me "the airfield burned for a week." The aircraft we saw burn must have triggered a series of secondary explosions which reached the other planes. The attack quickly had international repercussions. The Soviet government protested in the United Nations and the United States admitted responsibility. The story was front-page news but it soon became clear that both governments preferred to forget the matter, each for its own reasons. Nonetheless, some historians believe the mission profoundly affected the behavior of the Soviet leaders toward their Korean allies at a critical time. It probably drove another nail into the coffin President Truman was fashioning for Gen. Douglas MacArthur's tenure as commander of American and U.N. forces in Korea.

By early October 1950, MacArthur had enveloped the North Koreans with his amphibious landings at Inchon and the breakout from the Pusan perimeter to the south and was driving north across the 38th Parallel dividing the two Koreas. The People's Republic of China reacted by mobilizing its Manchurian army and committing it to attack across the Yalu River into North Korea as the U.N. forces approached.

Stalin was concerned not only with the possible defeat of his North Korean surrogates but also with the prospect that U.N. forces could soon be located near the Soviets' 15-mile-long border with North Korea. Stalin had to decide whether to intervene actively.

As I sat in the briefing tent of the 49th Fighter Group at Taegu, I was little concerned with these questions. I was being briefed for an armed reconnasissance flight over Chongjin. Our group had flown a mission there the previous day but couldn't find the airfield. Another flight had reconnoitered Chongjin that morning but found no activity. Chongjin received all this attention because our intelligence reported 200 North Korean pilots training in the northeast part of Korea, close to the border.

We were briefed about an hour before takeoff. The briefing officer didn't have much to show us, only a target folder and messages reporting the negative results of the earlier flights. During that stage of the Korean War, photographs or detailed maps of the target areas were not available.

Since we had to fly practically the entire mission without reference to the ground, and since there were no radio navigational aids along the entire flight path, our heading after takeoff and the time of flight would determine our letdown into the target area. A dominant factor was the forecast winds, especially at high altitudes where they were usually strongest. Unfortunately, the Soviets since mid-September had encoded all their weather reports, preventing us from knowing the weather over Siberia, north and west of Korea. The tops of the clouds rose along our path, so we climbed to 35,000 feet and later to 37,000 feet to stay above them. This caused our first deviation from the pre-flight plan.

Then, about 40 minutes after takeoff, flight leader Bud Evans called me on the radio and said his engine had thrown a blade from its exhaust turbine, forcing him to return to base. That was how Dief and I happened to be dropping through the clouds and going after those 20 planes sitting so invitingly on an airstrip somewhere near the Soviet-North Korean border.

I positioned our aircraft for a strafing pass on the northern line of aircraft, then made a sharp, banking turn to the left and fired on the southern line. I could see tracers carving through the aircraft and knew we were getting lots of hits, but there were no explosions. On my last pass, I decided to make sure of one clear kill. I concentrated my fire at one plane and saw it start to burn. Dief followed me closely in each pass. We exhausted our ammunition and were down to minimum fuel -- 400 gallons. Time to go home.

As I pulled off the target, turning right to our homeward course, I saw an island off the coast. "Oh, oh," I thought, "there's no island near Chongjin." After four minutes heading south, I could see a coastal point that matched the coastline at Chongjin. Now I was worried. Dief and I checked our maps and concluded we had struck an unimproved airfield shown at Rashin (now called Najin), 40 miles north of Chongjin and only 20 miles from the Russian border. I felt better.

That evening, after an initial debriefing and dinner, we were summoned to headquarters by Maj. Gen. Earl E. Partridge. I went over the mission completely. Then Partridge laid out a large map, pointed to an area inside the Soviet Union southwest of Vladivostock and asked if we could have attacked there. There were marked similarities to the terrain features we had described at Rashin. It was possible, but certainly not probable. I thought to myself, "My God, the wind would have to be much stronger than we expected to blow us way up there."

(I later figured the winds must have blown from 240

(from the southwest) at 200 miles per hour, twice as strong as predicted and 90 off the direction predicted by our weather forecasters. At that time, such high speeds of winds aloft were poorly understood. Only two months later I flew an F-80 westward over southern Japan with a ground speed of over 600 mph, which translates as a 200-mph tail wind.)

As we were leaving, Partridge said gently, and with some affection, "You'll get either a Distinguished Service Cross or a court martial out of this mission."

Dief met me when I returned from a mission the next day. His succinct words were: "It's hit the fan."

Soon the game was to be played at high levels. Dief and I became pawns as the big boys took over. The headline of the San Francisco Chronicle for Oct. 10, 1950 read: "Moscow Says U.S Jets Strafed Russian Airfield." From The Washington Post: "U.S. Raid on Soviet Plane Base Charged . . . ."

Soviet Deputy Foreign Minister Andrei Gromyko delivered the Soviet protest on Oct. 9:

"On October 8 at 16 hours 17 minutes local time two fighter planes of the U.S.A. Air Force of the type Shooting Star F-80 grossly violated the state frontier of the U.S.S.R. and, approaching in a hedge-hopping flight the Soviet aerodome situated on the seacoast in the Sukhaya Rechka area, 100 kilometers from the Soviet-Korean frontier, fired at the aerodrome with machine guns. As a result of the firing, damage was caused to property of the aerodrome."

To the Soviets, the mission was a surprising and confusing violation of their territory and frustrating evidence of their vulnerability.

Soviet radar probably picked up our F-80's about 100 miles from the Soviet border, then tracked us through the descent and lost us in ground clutter when we dropped into the river valley. A general alarm went out, but the Soviets had no aircraft, guns or missiles to meet the attack. Besides, it was Sunday afternoon; no one was around to do anything. To them, it was like Pearl Harbor, a dastardly sneak attack.

The Oct. 8 incident forced Soviet leaders to recognize the vulnerability of their forces, especially in the east, and their inability to defend against the more modern, experienced U.S. Air Force. Stalin decided to disengage from North Korea and stopped all further aid on Oct. 22, only two weeks after our attack.

Back in Washington, President Truman was dismayed by the attack. He held MacArthur responsible, suspecting him of deliberately acting to precipitate a war with the Soviet Union. Almost immediately after the incident, Truman ordered MacArthur to meet him at Wake Island, where they talked privately in Truman's airplane. MacArthur would survive as commander for only six more months.

On Oct. 19, Truman had Warren Austin, the chief American delegate to the U.N., admit the attack. His letter to U.N. Secretary Trygve Lie added: "The commander of the Air Force group has been relieved and appropriate steps have been taken with a view toward disciplinary actions against the two pilots concerned." Austin identified the pilots as 1st Lt. Alton H. Quanbeck and 1st Lt. Allen J. Diefendorf. In the meantime, Dief and I were in limbo. The Air Force's investigating officer, Maj. Harry W. Christian, discovered no physical evidence of a crime, and there were no gun-camera records because our base had run out of film."There is no real evidence in this case," Christian concluded.

But because of the political pressures from Washington, the Air Force ignored his recommendations and scheduled our general court-martial for Nov. 18 in Nagoya, Japan. We were accused of violating an order to stay clear of the Manchurian (Chinese) border, of strafing Soviet territory (a "country at peace with the United States") and of violating an order to make no attack without positive identification.

Our attorney, Maj. Bernard Katz, argued that the government was trying to locate us "in Manchuria on one count and in Russia on another count" and added: "They did positively identify a target, and they strafed a target that they positively identified. They identified it as a North Korean airfield, on which was contained certain aircraft, bearing the mark of a star. They had been briefed that any aircraft marked with a star found in North Korea was good game . . . ."

Both of us were found not guilty of all charges. But the court martial was closed to the public, and the results were never released. Air Force leaders wanted the Russians, and probably President Truman, to believe we had been properly punished.

The Air Force would not permit Dief or me to fly any more combat missions, reasoning that we would be in jeopardy if we were shot down and captured. Instead, Dief was assigned to a fighter squadron in the Philippines, where his new bride could join him. I was reassigned to a fighter-interceptor squadron in Japan, and then became aide-de-camp to Brig. Gen. Delmar T. Spivey, who had been present at our initial debriefing. I finished up my tour as a combat crew instructor with F-84's back with the 49th Fighter Group.

Alton Quanbeck, after 22 years in the Air Force, worked for the Brookings Institution, the Senate Intelligence Committee and the CIA. He is now a farmer in Middleburg.