One week later the first Morane-Saulnier MS 406 fighters donated by the French government arrived via Sweden. Ltn. Karu was appointed as Flight Commander to HLeLv 28, the unit to be equipped with this new equipment. As his flight became operational, it was stationed in Turku.
Lt. Karu was brimming with energy and fighting spirit now that he had a chance to fly against the enemy. True enough, the Moranes were armed with three 7,5 mm machine guns only and totally lacking radio equipment, which drastically decreased the usability of these fighters. Without radio, even receiver, a fighter pilot could find the enemy planes with luck only.
The 20 February 1940 was a beautiful, sunny and very cold day in Turku. The Morane flight was based in the airport of Artukainen on the western edge of the town. Lt. Karu kept near his "MS-321" with his mechanic, but he did not sit in the cockpit because it was too cold - more than minus 30 C. Suddenly the sirens wailed and almost at the same time the two men heard the sound of bomber engines. The air surveillance had failed once again...
Within a couple of minutes "MS-321" took off, trailing a small snow storm, well visible in 7000 m where the enemy bombers flew to avoid AA. Lt. Karu guessed that the bombers would be returning to the Soviet air base in Paldiski, Estonia and set his course to SE, taking altitude. The distance to Paldiski is about 300 km.
At 4500m he began to grope for the oxygen mask - but it was not there. It had been removed from the plane due to detected malfunction. At the same time he saw the enemy: nine DB-3 bombers, less vulnerable and faster than SB-2's. Moreover, the enemy was taking altitude, the bombers were now in 7500 m. Could the Finnish pilot fly that high without extra oxygen?
Lt. Karu decided to try. The enemy was nearly at his hands, he could not let the
bombers escape unpunished. He was experiencing shortness of breath and his vision
began to impair. Near the Estonian coast the Morane caught up with the enemy.
The chase had lasted about 45 minutes. The pilot saw also two 9-plane formations
of enemy fighters at a lower altitude.
Now the Finnish pilot had to make the final decision: fight or disengage? Lt. Karu was feeling physically very bad, lack of oxygen affected his brain, but with the power of his will he forced his body co-operate. He approached at the cover of the DB-3 tail until the range was less than 50 m. He aimed at the right engine of the wing bomber of the formation and pressed the trigger. The Morane's three machine guns ratlled and spewed tracer at the bomber: its engine caught fire and it began to dive. Despite his dizziness, Karu looked around and saw a lone I-16 approach from the rear. It was not in shooting range, however.
The Morane pilot struggled to shift his aim to the next bomber, then he fired in its right engine, which stopped. Lt. Karu made one more effort in shifting his aim to the left engine of the bomber, and fired. The DB-3 nosedived in flames.
Now Lt. Karu let his fighter dive in a nearly vertical dive, turning with ailerons to change the direction of coming out of the dive. He returned to level flight very near the Baltic ice. But he did not feel any better now. There was a terrible pain in his lungs ; strange lights flashed in his eyes ; his pulse raced. He was on the verge of fainting as he landed at Artukainen. Flying in 7500 m without oxygen mask took its toll. It took him a full 24 hours to recover.
The two victories were confirmed in an unusual way. The Swedish Coast Guard was constantly monitoring the Russian radio traffic, and they had intercepted a message about two bombers having been shot down near Paldiski by a "byelofinskiy vozhdushnyi bandit". This information was transferred to Finnish military intelligence...
