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Princeton, Indiana | Wishbone's post below about truck maintenance got me thinking about helicopters that require 4 hours in the shop for every 1 hour flying. That's a bunch of wrenching.
"Helicopters have a large number of moving parts, designed to minimal weight and high stress (fatigue) conditions. This, combined with a low tolerance for failure, results in high maintenance. Ratios of Maintenance Man Hours (MMH) to flight hours is often 3.5 to 4.5. That is, four hours of maintenance is conducted for every flight hour. Parts are replaced well before expected failure. Many parts are machined to very close tolerances. Metal used to manufacture parts have certifications regarding the source, treatments, and inspections. It is not unusual for spare parts to cost $5,000 to $15,000 with a few exceeding $50,000. Consequently, the current parts cost (in 1996) per flight hour of a Black Hawk is $1,602.70 ($351.54 consumable and $1,251.16 reparable). The Longbow Apache spares cost per flight hour is $3,851.18 ($444.20 consumable and $3,406.98 reparable)."
http://www.globalsecurity.org/military/systems/aircraft/rotary.htm | |
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Maintenance costs
