On average, the F35A has a critical failure every 4.5hrs of air time requiring 12 hours to repair (out of service hours, not man hours)
F-35B -- critical failure after 3 hours, requiring 15.5 hours of repairs.
F-35C critical failure after 2.7 hours before 9.6 hours for corrective maintenance time.
Elgin AFB has 17 mechanics per aircraft.
When you factor in the cost of keeping them in the air, it's around US $600M per aircraft.
And that is peace time.... Imagine what it would cost to keep these lumps in the air during a conflict?
Source:
http://www.defense-aerospace.com/art...%26s-cost.html
The most expensive dreadnaught ever built.