June 1944, having expended his ammunition in an extended dogfight, Sergeant Tomesaku Igarashi of the 50th Sentai used the propeller of his Nakajima Ki-43 to bring down a Lockheed P-38 Lightning near Meiktila, Burma. After the pilot bailed out, Igarashi attacked him in his parachute. The P-38 may have belonged to 10-kill ace Captain Walter F. Duke of the 459th Fighter Squadron who went missing in battle that day. Sergeant Shinobu Ikeda of the 25th Dokuritsu Chutai rammed his Ki-45 into Cpt. Roger Parrish's B-29 "Gallopin Goose" (42-6390) on 7 December over Mukden. Sgt. Ikeda and all except one crew member of the B-29 perished. Starting in August 1944, several Japanese pilots flying Kawasaki Ki-45 and other fighters engaging B-29 Superfortresses found that ramming the very heavy bomber was a practical tactic. From that experience, in November 1944 a "Special Attack Unit" was formed using Kawasaki Ki-61s that had been stripped of most of their weapons and armor so as to quickly achieve high altitude. Three successful surviving ramming pilots were the first recipients of the Bukosho, Japan's equivalent to the Victoria Cross or Medal of Honor, an award which had been inaugurated on 7 December 1944 as an Imperial Edict by Emperor Hirohito. Membership in the Special Attack Unit was seen as a final assignment; the pilots were expected to perform ramming attacks until death or serious injury stopped their service. The Japanese practice of kamikaze may also be viewed as a form of ramming, although the primary mode of destruction was not physical impact force, but rather the explosives carried. Kamikaze was used exclusively against Allied ship targets. Bulgaria Two rammings () were performed by Bulgarian fighter pilots defending Sofia against Allied bombers in 1943 and 1944. The first one was by poruchik (Senior Lieutenant) Dimitar Spisarevski on 20 December 1943. Flying a Bf 109 G2 fighter, he rammed and destroyed American B-24 Liberator #42-73428 of the 376th Bomb Group, though it is unknown whether the collision was intentional. The Bulgarian military said it was deliberate, and increased his rank posthumously. The second ramming was performed by poruchik Nedelcho Bonchev on 17 April 1944 against an American B-17 Flying Fortress. Bonchev succeeded in bailing out and surviving after the ramming. After the fall of the Third Bulgarian Kingdom 9 September 1944 he went on flying against the Germans. His Bf 109 was shot down during a mission and