more efficient.

 Paul Lamar


 When my father was a Flight Engineer at United flying the DC-7C, the
 average
 time between in-flight shutdowns (on each airplane) was 400hr.

 I also had a long conversation with a professor of mine who was a USMC
 C-119
 squadron commander, he had buckets of trouble with the 3350TC, had to get
a
 CW
 engineer in to consult and teach everybody how to operate the engines, and
 reliability got to an acceptable level.

 It is probably more of a function of that particular design then that of
 the
 whole idea of compounding.

 The heat efficiencies are just too good to overlook. It's a shame that the
 commercial GA manufacturers are completely hamstrung by 1) certification
 costs,
 and 2) a complete lack of want to change the product.

 Jim Tiemann

 As I said most of the trouble was with the exhaust valves.
 When a valve broke it would take out the turbine blades.
 The rotary has no exhaust valves.

 Paul Lamar


 The PRTs were made to fail-soft in that event - the disc would become
 frangible and completely take itself out (in theory also not destroying
the
 turbine housing/exhaust pipe) in the case of an imbalance. (like a valve
 trying to make it down the exhaust) and also they were on fluid clutches
to
 help disconnect themselves in case of failure.

 Jim Tiemann

Where's figure 11.  Sounds interesting.

Van

Thanks,

Van