HI THERE
Cape Air runs over 70 twin Cessna 402s.
in 2007 they had two of their TSIO520 exploded. the counterweights came loose and literally
destroyed the case and engine. they shut down operations and rebuilt about 100 engines in a week.
IT TURNS OUT
they were running them at minimum RPM and HIGH manifold pressure. within limits stated in the operating manual.
something like 2000 RPM and 40" MP.
CESSNA, FAA, Continental Engines, TAS aviation and others met to examine the destroyed engines.
THE RESULT
- DO NOT use the extremes of the power chart; notwithstanding that the information remains in the Cessna operation manuals of their aircraft
- Continental issued a service bulletin restricting certain power settings
NOW
they run the engines at 2300 RPM and 30" MP and about 14.3 GPH fuel flow.
peter> To: lml@lancaironline.net
> Date: Fri, 26 Jul 2013 06:22:33 -0400
> From: bknotts884@earthlink.net
> Subject: [LML] Re: Potential Problem-Engine Vibration
>
> For no particular reason, I was browsing through the Continental Engine
> Maintenance and Overhaul Manual (M-18) for the TSIO-550 family of
> engines. The engine specifications are listed on pages 2-22 through
> 2-33. Each of these engines has a "Minimum Cruise RPM" of 2300 RPM. I
> was unaware that there was any RPM restriction (other than max. RPM) on
> these engines.
>
> I never go that low. My minimum cruise RPM is 2400.
>
> Does anyone use a cruise RPM below 2300?
>
> Barry Knotts
> LIV-P, N4XE
>
> --
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