ABS Fly-In Savannah, Georgia, May 16-19 See Page 3 - American ...

www.bonanza.orgCurrentsContinuedDiagram 1The bad feature of not havingthe limit micro switches in the cir -cuit in manual is that, if the switch isheld up or down after the prop pitchchange motor pinion gear reachesthe end of the ring gear, the pinionleaves the ring gear and the leafspring returns the pinion into reengagementwith the ring over andover until the man ual switch isreleased. This wears out both gearsunnecessarily and there is the dis -tinct possibility that the spring maybreak, as has happened numer oustimes. This leaves the pin ion disengagedwith the ring gear so the pilothas no control of the propeller. Itis now parked in either full fine orcoarse pitch depending on which waythe motor was running at the timethe spring breaks.Diagram 2Diagram 3This is what I would do if myairplane had a Beech propinstalled, the governor failed,and I was unable to get it back intoserviceable condition. What you dowith your airplane may be different,but I think this is the best solution.All of the airplanes with a gover -nor have a pitch change relay boxwith two relays inside. One increasesRPM and one decreases RPM. Ifthe pitch change relays are operatingI would re-wire the cockpit switch toduplicate the wiring diagrams of thefirst 1,820 airplanes. You can see thatthe two diagrams (Diagram 1 andDiagram 2) differ in layout but thecircuitry is identical. The only differenceis the terminal strip used throughD-1116. This would have the manualswitch operating the holding coils ofthe relays with the ground for the holdingcoils through the limit switches.When the pinion gear gets to aboutthe last tooth on the ring gear the limit52 AMERICAN BONANZA SOCIETY FEBRUARY 2013