Why Aren’t Airplanes Serviced at X number of miles

[Steve]

Something I’ve always wondered; why are aircraft serviced at XX number of HOURS and cars at XX number of miles? Mainly I’m talking about the engines. From what I’ve read a lot of commercial jet engines need an overhaul at about 1,800 to 2,000 hours, depending on the engine. Aircraft also put huge amounts of stress on landing gear and brakes just as we put stress on our car/truck brakes and suspension systems. Obviously the aircraft makers might be erring on the side of caution since an aircraft won’t get stranded beside the road – THEY CRASH. And obviously our cars have a mileage gauge so it’s easier to go by that, but it would be rather easy for manufacturers to put a total time engine running gauge in cars if they wanted to do that. Just something I’ve always wondered about.

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[dollman0]

I think this is more applicable toward the difference between highway equipment and other industrial machinery.

Anything classified as automotive is referred to as miles and non-highway use hours as their service intervals. I don’t understand the separation myself.

I do mostly heavy equipment and some diesel engines go 10,000 hours before they get run down. In the old days, oil changes were done at 100 hours and today that number is around 300 hours. I worked for a trash company who used synthetic oil, their oil changes were 450 hours and they did oil analysis to verify their maintenance program.

Airplanes have a constant operating range much like a stationary engine running a generator or a pump. Automobiles have a wide range of operating conditions, this may be the trend toward using a distance factor as apposed to time in service.

[W00DBar0n]

I know most newer light trucks are not going by mileage these days, they go by a mix of time, rpm and strain(power usage) to determine oil changes. The computer will give you a percentage of life left for the fuel and oil filter(s)

[Dave]

I know that airplane tires are removed after x number of landings.

[Steve]

Maybe it’s comparing “apples to oranges” to compare cars to airplanes as far as service schedules and whatnot. Whatever the reasoning, the aircraft industry must be doing it right since we have passenger aircraft flying 40 or even 50+ years at times with regular maintenance procedures. And the Air Force still flies one of my all time favorite planes – the majestic B-52 bomber after 50+ years AND is projected to use them for a while into the future. That means some of those planes will have flown 60, 70 years or so! I think that is awesome. I do know they require significant upgrades and servicing over time though but it’s still awesome and a suppose a testament to past/present American aircraft manufacturing quality.

[Author]

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