I didn’t realize that there are still C5s in service. I suppose that is what the Reserves and Natl. Guard are using..
There are always a few airplanes in a unit that are hard down for maintenance. Inspections, reworks, etc. can take an airplane out of service for extended periods. In my old Marine F/A-18 squadron having 8 out of 12 jets up at any given time was considered exceptional. I don’t think there is a helicopter big enough to sling an intact F22.