the 4-week training course in organizing and operating very heavy bombardment units in the field. While the cadre was at AAFSAT, the influx of new personnel continued at McCook. After the return of the squadron staff in June 1944, the squadron organized new crews and conducted an intensive program of ground and flying training using B-17 aircraft to practice takeoffs, landings, instrument and night flying, cross-country navigation, high altitude formation flying, and bombing and gunnery practice. The development of the B-29 as an operational weapon had been plagued since an early flight test on 28 December 1942, resulted in an engine fire, culminating in a massive emergency modification program in the winter of 1943–44 ordered by General Henry H. Arnold, Chief of the Army Air Forces, and nicknamed the "Battle of Kansas". In particular, the program sought to resolve a spate of problems with serious engine fires and faulty gunnery central fire control systems. All B-29s modified in this program were diverted to the 58th Bomb Wing to meet President Franklin D. Roosevelt's commitment to China to have B-29s deployed to the China-Burma-India Theater in the spring of 1944, leaving none available to equip the 12 new groups being formed in the 73rd, 313th, and 314th Wings. The 9th Group received its first training B-29 on 13 July 1944. After four further months of training the group commander declared the unit ready for movement overseas, and its ground echelon left McCook for Seattle, Washington, Port of Embarkation on 18 November 1944, traveling by troopship to the Mariana Islands on a voyage that required thirty days. The ground echelon of the group debarked at Tinian on 28 December and was assigned a camp on the west side of the island between the two airfields. The air echelon of the 1st Bomb Squadron began its overseas movement on 15 January 1945, from its staging base at Mather Army Airfield, California, after accepting the first of its 14 new B-29s at Herington Army Airfield, Kansas. The squadron's bombers proceeded individually by way of Hickam Field, Hawaii, and Kwajalein to North Field, Tinian, with the first three arriving on 18 January 1945. The final two of the original 14 airplanes arrived on Tinian on 3 February by which time the squadron had already flown three practice missions to the Maug Islands in the Northern Marianas. The 1st Bomb Squadron conducted its first combat mission