Saturday, August 1, 2009

F22 performance figures

From Aviation Week.
"The F22's variable cost per flying hour $19000." Not exactly cheap. Assuming fuel consumption in the ball park of the old F106, and $2.69 a gallon, fuel would be $6000, so the rest, $13000, is wear and tear, tires, and brakes, and drag chutes, and engine overhauls, and black box repair & replace.
"The mission capable rate has increased to 68% from 62%." Not good. We were required to maintain 71% mission capable rates on the F106, and that was a vacuum tube airplane forty years ago, whose avionics needed repair after every single flight. F22 is all solid state and the black boxes ought to last ten times longer than vacuum tube ones.
"Mean time between maintainance action has matured from 0.97 hour in 2004 to 3.22 hr demonstrated in Lot 6 aircraft." Fair. Assume average sortie time of two hours, that means half the sorties will come back unbroke, ready for the next sortie for merely refuel and rearm. The F106 was worse, most sorties came back broke and needed fixing before the next sortie.
"The current software's stability exceeds 20 hr." I think that means the software crashes hard about every 20 hours. Let's hope the pilot has a reset button. Windows XP is better than that, and that's not saying much.
"The diagnostic software detects system faults and isolates them 92% of the time." Not bad. The F106 lacked diagnostic software. We fixed it by swapping black boxes until it worked again. Fortunately the black boxes were mounted in very easy to access racks, with quick change fasteners.
"Direct maintenance man-hours per flying hour have improved to 10.48 this year from 18.1 in 2008, exceeding the requirement of 12 manhours/flying hour." I can't remember what it was on the F106, but 10 manhours is pretty good.

F22 is now out of production as of last week in Congress, but the 187 aircraft already bought will be flying for decades.

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