The C-17 Engine

There are some technologies involved there in the military engines that you wouldn't want to be out available in the commercial world. So yeah, it's unusual for a military engine to be used that way. The overture schedule has slipped many times or at least several times in the past. Will it slip again in the future? We'll see,. But I don't think it would be a huge surprise given that they are at this stage now with engine development for this aircraft.