It's not totally arbitrary though. The maintenance for engines (and other systems) works pretty close to reality with latest more unreliable power-plants that are pushed to the max are installed on military ships and aircraft while civilian or support ships/planes get slower engines with better fuel economy. And with higher heat comes more need for cooling which again adds more points of failure and breakdowns.
Modern naval powerplants are incredibly reliable, and take less maintenance than you'd think. The big difference is fuel economy. Gas turbines are good for power-to-weight and maintenance, but eat fuel.
Some real jet engines have a maintenance life in the span of hundreds of hours just, and military guns on for example battleships can only fire a few hundred times before they need to swap out the barrels for overhaul.
Those tend to be Russian engines. Better metallurgy means that western engines have lives not too dissimilar from civilian engines.
And wear on battleship guns is tremendously variable. I don't have my references on hand at the moment, but I do recall that the short-life winner were the guns of the Vittorio Veneto class, which only lasted 150 rounds. The last battleships (Iowas) had an additive in their powder when recommissioned in the 80s which cut barrel wear so much that they started to have to worry about fatigue instead of wear.
Like the new naval railguns (in development), they can fire over 100 nautical miles doing stupid amounts of damage, they break down after a few shots.
That's one of the main reasons they haven't entered service yet.
Large Civilian passenger jets do need significant maintenance, however not to the extremes required by an f22.
Taking an older 474 model as an example they require around 1-2 hours of preflight checks for 6-12 hours of daily use, around 2-3000 man hours of routine maintenance a year plus something like 20000 man hours of overhaul every 20-40000 flight hours.
Which older 747 are you using for that? I can't find the exact numbers in the linked document, but this is an area where the manufacturers continue to work hard to bring down costs and time.
Most models have defects requiring mandatory upgrade at certain flight hour milestones, which might add another 20000 manhours million dollar cost by the 60000 hour mark.
Try 'all models'. Nobody has built an airliner which doesn't acquire cracks in annoying places, and it happens a lot more than you think. I'm not sure that AD compliance and the like take as much as a D-check over that amount of time. A lot of them happen during C and D checks, which saves time.
Perhaps it costs something like 5 manhours of maintenence per flight hour.
In total it costs something like 20000 per flight hour including fuel, crew, maintenance parts etc.
That seems slightly high. I'm turning up numbers that are more like half that, although this topic is obviously complex enough that you could argue it either way.
A f22 of course is far more expensive. Around 40 me hours per flight hour, main fence needed every 3 hours of flight time. Pretty close to an older commercial jet really.
40 man hours per flight hour? That's the sort of thing you'd see on the F-14. Those numbers date back to 2008 or so, and I suspect they're framed to get as many hours in as possible. The program requirement was 12 direct hours per flight hour, and I think that's maybe twice the value of the Super Hornet.
