Does the adoption of the new engine mean that, if C-5 loses an engine overseas, the Air Force could buy a replacement from a commercial airline?
Maybe in a war time emergency. Unlike the original purchase of C-5's and engines, the Air Force is buying plenty of spare engines. Supposedly there will be 500 engines bought from GE. There were to have been 112 planes going through the AMP and RERP, but one of the C-5B's crashed in April, so there will only be 111. That means there will be 444 new engines put on C-5M's and 56 spares. The spares will account for about 11.2% of the engines acquired or about a 1:8 ratio of spares to installed engines. There will be one spare engine available for every two aircraft.