I think it's a very good question. For commercial aircraft, this article would suggest massively less wall clock hours in maintenance than in flight, about a r

I think it's a very good question. For commercial aircraft, this article would suggest massively less wall clock hours in maintenance than in flight, about a ratio of one to ten (assuming 12 flight hours per day and 16 hour days in maintenance). Maintenance man-hours would be about three per flight hour. So comparable to the cockpit crew. https://en.wikipedia.org/wiki/Aircraft_maintenance_checks https://en.wikipedia.org/wiki/Aircraft_maintenance_checks A check: 500 hours of flying, 20 hour, 200 man-hour (0.04 h/h, 0.4 mh/h) C check: 2 years of flying: 2 weeks, 6000 man-hours (0.03 h/h, 0.7 mh/h) D check: 6 years of flying: 2 month, 50,000 man hours (0.03 h/h, 1.9 mh/h) EDIT: this doesn't include unscheduled maintenance.