The target was the Nakajima Aircraft Company's Musashi engine plant just outside Tokyo. 111 B-29s took off, Seventeen of them had to abort due to the usual spate of engine failures. The remainder approached the target at altitudes of 27–32,000 feet. For the first time, the B-29 encountered the jet stream, which was a high-speed wind coming out of the west at speeds as high as 200 mph at precisely the altitudes at which the bombers were operating. This caused the bomber formations to be disrupted and made accurate bombing impossible. Concerned about the relative failure of the B-29 offensive to deal any crippling blows to Japan, General LeMay issued a new directive on 19 February. General LeMay had analyzed the structure of the Japanese economy, which depended heavily on cottage industries housed in cities close to major industrial areas. By destroying these feeder industries, the flow of vital components to the central plants could be slowed, disorganizing production of weapons vital to Japan. He decided to do this by using incendiary bombs rather than purely high-explosive bombs, which would, it was hoped, cause general conflagrations in large cities like Tokyo or Nagoya, spreading to some of the priority targets. The first raid to use these new techniques was on the night of 9–10 March against Tokyo. Another wing—the 314th Bombardment Wing (19th, 29th, 39th, and 330th BG) commanded by Brig. Gen. Thomas S. Power—had arrived in the Marianas and was stationed at North Field on Guam. A total of 302 B-29s participated in the raid, with 279 arriving over the target. The raid was led by special pathfinder crews who marked central aiming points. It lasted for two hours. The raid was a success beyond General LeMay's wildest expectations. The individual fires caused by the bombs joined to create a general conflagration due to strong winds of some 17 to 28 mph (27 to 45 km/h) at ground level, that prevented a more specific firestorm event. When it was over, sixteen square miles (41 km2.) of the center of Tokyo had gone up in flames and nearly 84,000 people had been killed. Fourteen B-29s were lost. The B-29 was finally beginning to have an effect. By mid-June, most of the larger Japanese cities had been gutted, and LeMay ordered new incendiary raids against 58 smaller Japanese cities. By now, the B-29 raids were essentially unopposed by Japanese fighters. In