It takes bleed air which is hot and uses the energy in the hot air to cool
and dehumidify it. It is basically a series of heat exchangers, expansion
turbines, compressors water traps/sprayers and valves. The rotating group
turns something like 100,000rpm and overhauling one in an MU-2 can be
upwards of $35,000. They typically last about 4000 hrs. The alternative is
a vapor cycle machine which is better at cooling but even more expensive.
Cabin windows and windshields last about 20yrs or so (4000 hr) and on a MU-2
cost $70,000 to replace. Nobody thinks about these things as being typical
costs but they can add significantly to the operating cost over the lifetime
of an airplane.

Mike
MU-2


"Richard Kaplan" wrote in message
news:1120968289.ca16ce6fd2c4644fb07a8b68b04395b6@t eranews...
What is an air cycle machine?

--------------------
Richard Kaplan

www.flyimc.com