Archer Tach Red Arc

Greg Esres wrote:
: Does anyone know of any legitimate reason for an Archer to have a red
: arc, other than max RPM?

The reason is for resonance issues with the Sensenich 76" (EMS8 or whatever)
prop and a Lycoming O-360-A3A (hollow-crank) engine. Our 140 has the Avcon engine
upgrade to 180 HP and has the limitation specified in the STC and the supplemental POH
that came with the STC.... but *only* if the engine is a -A3A. If it's a -A4A, it's
got a solid crank and doesn't require the limitation.

I'd say check the logbooks for propeller model and engine model suffix. I
believe the wording is, "Avoid prolonged cruise power within the 2150-2350 rpm range"

I think they discovered this issue shortly after the -180's came out, so I'm
surprised that an Archer POH doesn't mention it.

-Cory

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* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
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