VAF Forums

VAF Forums (https://vansairforce.net/community/index.php)
-   Propellers (https://vansairforce.net/community/forumdisplay.php?f=19)
-   -   MT P860-3 Prop Gov fail. (https://vansairforce.net/community/showthread.php?t=140879)

vic syracuse 08-23-2016 10:48 AM

Unfortunately, I have to agree, Weasel. It's not making any sense to me right now, and hasn't for the last week. First, I think the data field for the failures is kind of low---yes, they might be from a close-timeframe batch, but there sure is a large time-in-operation spread between them. For piece of mind for me in the meantime I am changing the governor to a PCU5000X (I was going to use a Hartzell, but got the wrong one shipped from Van's last week). I currently have about 1100 hours on my P-860-3, and had it overhauled at 950 hours.
Something must have changed in the manufacturing process for the MT governors, and I hope we can find out soon.

BTW, the The P-880 governor someone mentioned in an earlier thread is for a counterweighted prop. The P-860-3 is the correct model for the RV-10.

Vic

Auburntsts 08-23-2016 10:58 AM

Quote:

Originally Posted by Weasel (Post 1105778)
Anyone care to venture why they mention electronic ignition and high compression. The failures here do not support the remark.

It's a head scratcher. Besides having only mags (as already noted), I have stock 8.5 low compression pistons.

I'm still curious as to how they are able to come out with an SB and a fix so fast being that outside of external pics they have not examined either Myron's nor my PG.

Weasel 08-23-2016 12:02 PM

Quote:

Originally Posted by Auburntsts (Post 1105810)
It's a head scratcher. Besides having only mags (as already noted), I have stock 8.5 low compression pistons.

I'm still curious as to how they are able to come out with an SB and a fix so fast being that outside of external pics they have not examined either Myron's nor my PG.

Well, hopefully this information will get back to them before they actually publish the SB.

DanH 08-23-2016 12:06 PM

Quote:

Originally Posted by Auburntsts (Post 1105810)
It's a head scratcher. Besides having only mags (as already noted), I have stock 8.5 low compression pistons.

I'm still curious as to how they are able to come out with an SB and a fix so fast being that outside of external pics they have not examined either Myron's nor my PG.

Perhaps you three are not the only failures.

GaryK 08-23-2016 12:15 PM

Vic,
Is the PCU5000 the same form factor as the MT. I have the Sam James cowl and plenum so the PG cylindrical shape is important unless I modify the plenum.

Thanks
Gary

Auburntsts 08-23-2016 12:19 PM

Quote:

Originally Posted by DanH (Post 1105832)
Perhaps you three are not the only failures.

My thoughts as well, although you would think that multiple failures would be relatively common knowledge--perhaps not. However, methinks that something was already in the works based upon some kind prior knowledge, especially since the SB is apparently going to target only a specific manufacturing date range of the model and not all of them.

vic syracuse 08-23-2016 01:31 PM

I have scoured the Internet and can't find any other failures, which I find hard to believe.

I will le tyou know on the form factor.

Vic

rvbuilder2002 08-23-2016 01:47 PM

Quote:

Originally Posted by Weasel (Post 1105830)
Well, hopefully this information will get back to them before they actually publish the SB.

I have fwd'ed the details about the 3 RV-10's that have been provided here, to Martin at MT.

woxofswa 08-23-2016 05:09 PM

This gets more confusinger by the day. I dug deep into my documents and there is a card (mostly in German), that says that the 860-3 is specified for 360
Series engines and 2500 RPM.

I've had supposed experts say that the ratio difference of WD and ND is a big huge ticking bomb deal and others say that it is very minor that all it does is slightly vary the speed of the pump and slightly change the distance throw of the arm to make a given change. I've heard of a well known pilot who purposely runs a ND ratio pump on his WD because he likes the feel better and had never had a
problem. The external gear on my failed unit is in pristine condition.

I emailed MT, sent my pictures, and offered any help I could and they never answered me back.

Chkaharyer99 08-23-2016 05:11 PM

Quote:

Originally Posted by vic syracuse (Post 1105807)
Unfortunately, I have to agree, Weasel. It's not making any sense to me right now, and hasn't for the last week. First, I think the data field for the failures is kind of low---yes, they might be from a close-timeframe batch, but there sure is a large time-in-operation spread between them. For piece of mind for me in the meantime I am changing the governor to a PCU5000X (I was going to use a Hartzell, but got the wrong one shipped from Van's last week). I currently have about 1100 hours on my P-860-3, and had it overhauled at 950 hours.
Something must have changed in the manufacturing process for the MT governors, and I hope we can find out soon.

BTW, the The P-880 governor someone mentioned in an earlier thread is for a counterweighted prop. The P-860-3 is the correct model for the RV-10.

Vic

Vic,

Thank you for the post. It helps validate the decision I made.

The MT P860-4 on my RV-8 was due to be sent back for the six year inspection/rebuild... MT quoted me $800.00 for the service and indicated a two week turn around.

After reading about the MT prop governor issues you all were having on the RV-10's (MT P860-3) I decided to ground my plane, remove the MT PG and apply the $800 dollars I would have spent on the MT PG rebuild towards a brand new PCU-5000X from Aero.

Aero sold me a new PCU5000X for $1,200, comes with a warranty and isn't due for a rebuild for 72 months. Should have a new one in five days. It seemed the prudent way to go.

To those of you who have had PG failures. Good job getting your planes safely on the ground. Best wishes in your resolving your problem at the lowest possible expense. Most of all, thank you very much for sharing your experiences with us.


All times are GMT -6. The time now is 06:13 AM.