Intermittent prop overspeed PA-30

by **Alan South** » Wed Jan 28, 2009 12:09 am

I have these two symptoms and would value advice on how best to troubleshoot:

(a) Prop sometimes overspeeds by approx 100rpm during the take off roll and climb out. Sometimes the rpm is accurately controlled to the 2700rpm redline, sometimes it is not. Problem is intermittent and random even on consecutive flights on the same day. The prop is definitely overspeeding, not just the tacho

(b) Prop sometimes ‘sticks’ when changing from cruise rpm (2300) to approach rpm (2400). Moving the prop lever initially has no effect, until it is moved further than normal. Prop suddenly jumps to 2500rpm and then can be controlled as normal.

The two symptoms could be totally unrelated, of course

Governor was overhauled in 2005, prop also in the last few years.

Advice welcomed

Alan

by **MillenniumFlight** » Wed Jan 28, 2009 2:43 am

Is it doing this on BOTH engines?? (you did say PA-30, right?).

by **Alan South** » Wed Jan 28, 2009 7:45 pm

by **Zach Grant L1011jock** » Wed Jan 28, 2009 9:08 pm

by **Jody Brausch** » Wed Jan 28, 2009 11:45 pm

by **Alan South** » Mon Feb 02, 2009 10:42 pm

by **MillenniumFlight** » Wed Feb 04, 2009 11:41 pm

by **steen** » Thu Feb 05, 2009 6:55 am

by **N3322G** » Thu Feb 05, 2009 4:35 pm

by **Jody Brausch** » Sun Feb 15, 2009 3:44 pm

Alan,
Did you ever get to the bottom of your prop overspeed issue? I am curious as what you may have discovered.

by **Jeffrey Barrett** » Thu Apr 09, 2009 2:42 pm

I had the same problem with my port engine, but my tack was reading 3000 rpm at first I thought it was a tack problem. After take off when I pulled back on the prop control the tack needle with the L on it did not move. I returned and landed. After reading this I am going to swop the prop governers and see what happens. Thanks for the great pointers.

by **Zach Grant L1011jock** » Thu Apr 09, 2009 3:23 pm

Jeff,
Are you sure it was the prop or was it the tach. It is very easy to tell in a multi engine aircraft when something goes overspead if you listen to the "beat". If in fact your engine went to 3000rpm as you went around the pattern (at least 2 minutes), I would advise you to contact your shop with the details, as the prop and engine will have to be torn down and inspected. Sorry to be the bearer of bad news but that is the requirements set forth in the Lyc and Hartzell service documants.
-Zach

by **Jeffrey Barrett** » Thu Apr 09, 2009 3:56 pm

I need to check the tack first. I was unaware of that reqiurement. But what has to be done has to. Thanks.

by **Alan South** » Tue Apr 14, 2009 9:43 pm

Intermittent prop overspeed PA-30

Intermittent prop overspeed PA-30

Prop overspeed

Prop overspeed

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