Date: 12 May 99 02:49:10 From: email@example.com (Stephen H. Westin) Organization: Cornell University Program of Computer Graphics References: 1
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"Frank Muenker" <firstname.lastname@example.org> writes: > I recently noticed on various trips that cargo planes seem to be generally > very old. > I've seen lots of 727, DC10-30, 747-100 and even DC-8/707, but hardly ever > any new aircrafts. > Shouldn't cargo airplanes have the same problems/calculations concerning > fuel consumption, maintenance costs, etc. ? No. Cargo planes almost all fly much less than an airliner. Think about it: most airliners are in the air from 6:00AM to 12:00PM, or as much of that time as can be managed with stopovers, airport restrictions, etc. A FedEx 727 basically makes one run a night. Charter freighters sit idle until needed. What that means is that direct operating costs (fuel, maintenance, etc.) for a freighter are low relative to the fixed cost of owning the airplane. So buying an older, cheaper plane that burns more fuel and demands more maintenance makes a lot of sense. And maintenance-related delays of an hour or two are generally much less critical when the payload doesn't get bored, need to eat or go to the bathroom, etc. Not to mention that with slower accumulation of hours, major maintenance is less of an issue. It may be possible to buy an old airliner that, by passenger standards, is pretty close to demanding major maintenance, but fly it for years in charter cargo service before that number of hours comes up. The same tradeoffs apply, actually, to military planes: the KC-135 will live beyond its 50th birthday in service, partly because the planes are flown so little compared to airliners. -- -Stephen H. Westin Any information or opinions in this message are mine: they do not represent the position of Cornell University or any of its sponsors.