> > > > To complete ones education on the advantages of the rotary engine

one must study the history of the aircraft piston engine.

This is a very concise history of the the aircraft engine
you can download.

www.enginehistory.org/OX5to3350.pdf

I found it interesting that later models of the R3350 turbo

compound

engine gave up to 3000 hours of service in airline use.

Early non-turbo compound versions used in the B29 were lucky to

get

100

hours.

Paul Lamar

They did flog them for many hours but more significant was the MTBF

(mean

time before failure) figure.  FWIW, I talked to a man who was a

mechanic

working on the Connie engines who told me that the airplane averaged

only 10

hours between engine shutdown events (due to engine problems).

That's

about

40 hours MTBF per engine.  There was little left of the original

engine

when

it reached 3000 hours.

Tracy

That 10 hours is a very unlikely number as the 24 hour non-stop
Connie flights from San Francisco to London would not be possible.
Probably several thousand B29 sorties to Japan would also not be
possible. There appears to be a big difference of opinion
on the reliability of the R3350TC.

Paul Lamar

It sounded unlikely to me too.   He also said it was not uncommon to see
commercial flights of the Connie arrive with one engine feathered.  They
didn't see an engine out as a reason to scrub the flight.  Must have

made

for some nervous passengers if true!

Tracy

Now that I will buy. They improved the instrumentation to the point
they could detect trouble with the exhaust valves before they broke
up and took out an expensive exhaust turbine. Since shutting one
engine down was a non-event as far as handling and continued flight
was concerned they just did it and continued on to their destination.

I was on an Air Canada 747 flight from Toronto to LA and we lost an

engine.

We were only about a 1/2 hour out so we turned around and returned
to Toronto.

Here is a funny story from a friend of mine that was a B36 pilot.
The B36 used observers stationed in the aft fuselage that watched
the six R4360 corn cob engines in flight for signs of smoke and other

engine

and prop problems. One observer went on the intercom and says
excitedly to the pilot; "We lost number five engine Sir." The pilot
said to the flight engineer; "Feather number five." The observer then said
more excitedly; "Sir you don't understand...... The engine fell off
the wing!" :)

Paul Lamar

Mark wrote:
We had a 72 year old contractor (technical instructor) at work who worked on
Connies for Qantas in the late fifties or early sixties. From his accounts,
3000H on wing would have been an exceptional engine.

One of the roles of the Flight engineer was to scan the 144 plugs, one at a
time with an Oscilliscope. If they found a jug where both plugs weren't
firing , they would shut down and feather that engine before that cyclinder
seized. In that era, flight diversions were common, and accepted as part of
air travel. Today a captain can go there whole career whichout ever
experiencing an IFSD.

An old captain was asked how many engines he'd want on a plane to truly feel
safe. He thought about it for a while and said, "If my Flight E tells me,
"Sir you've lost No.16!", and I have to ask, "On which wing?", I have anough
engines!

Mark Wrathall
http://members.aon.at/wrathall/rotary/

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