Allison J33 Turbojet
By 1944, General Electric and the U.S. Army realized that more powerful engines were needed than the engines GE was developing. Using the British Whittle WB.2 turbojet as a starting point, the I-40 was developed by GE and first flew in the XP-80 in 1944. Using a new designation system, the I-40 was re-designated the J33 with responsibility for further development passing to Allison in 1945.
Allison produced more than 6,600 J33-A-35s for the Air Force alone.