The Boeing T50 was a small turboshaft engine produced by Boeing. It was the first turboshaft engine to ever power a helicopter: a modified Kaman K-225 in 1951. Based on Boeing's earlier Model 500 gas generator, the T50's main application was in the QH-50 DASH helicopter drone of the 1950s. An up-rated version designated Model 550 was developed to power the QH-50D and was given the military designation T50-BO-12.