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
redesignated the J33 with responsibility for further development
passing to Allison in 1945.
Allison produced more than 6,600 J33-A-35s for the Air