MT P860-3 Prop Gov fail.

[woxofswa]

Thanks Rob, I've posted that too. I found out about the catalog glitch from Hartzell tech support who expressed that for a while they have wished Van's would both correct the listings and list the exact Hartzell part number as well.

I have passed the message to Scott R and he said he would look into it.

[Auburntsts]

Originally Posted by woxofswa

Thanks Rob, I've posted that too. I found out about the catalog glitch from Hartzell tech support who expressed that for a while they have wished Van's would both correct the listings and list the exact Hartzell part number as well.

I have passed the message to Scott R and he said he would look into it.

I got an email from Van's yesterday confirming the "O" model is for the narrow deck 540 and the "IO" model is for the wide deck 540. They also stated that they plan to discontinue selling the "O", narrow deck model as the D4A5 engines they sell are wide decks.

[Aggie78]

Originally Posted by Dustyone

I have just heard back from MT in Germany.

There is soon to be a new SB31 with expanded serial numbers to address the recent failures.

Although this will mean grounding my aircraft,cudos to MT for responding so quickly.

Letter below:

But we have another issue with the P-8XX-3 series , during operation a flyweight assembly could become loose.
In this case the damaged flyweight assembly will result in an overspeed or underspeed condition .

Shortly we will release the SB 31 because of that issues.
According this SB 31 your governor with the S/N 11G028G is affected .

This modification is free of charge.

If you have any more question , do not hesitate to contact me.


Best Regards

Andreas Seperant

Engineering / Tech Support
MT-Propeller Entwicklung GmbH
Airport Straubing-Wallmuehle
D-94348 Atting - GERMANY
phone: +49( 0 )9429-9409-44
fax: +49( 0 )9429 - 8432
www.mt-propeller.com

Wonder if sending it back to comply with the SB will also reset the 2000 hour/72 month overhaul clock?

Any mention of that?

I have one of the P-8XX MT governors, and am waiting to see the new SB to see if my serial number is in the affected group...my unit will be up against the calendar limit next year.

If I have to send it back due to the SB, I'm not wanting to pull the thing off twice in 6 months...once for this and again for the overhaul...I want to get it all done at once.

It would be good of MT if (as part of the fix) it does reset the overhaul clock...worth the hassle of having to pull it off in the first place, then.

[rvbuilder2002]

Originally Posted by woxofswa

Thanks Rob, I've posted that too. I found out about the catalog glitch from Hartzell tech support who expressed that for a while they have wished Van's would both correct the listings and list the exact Hartzell part number as well.

I have passed the message to Scott R and he said he would look into it.

My understanding is that the O and IO designations were based on information originally provided by someone at Hartzell (since Van's doesn't have an airplane with a narrow deck there would be now way to personally know).

I am also not aware of Hartzell going beyond wishing, and actually tell anyone that the designation was incorrect.

(but I could be wrong)

[woxofswa]

Scott, no disrespect to you or Van's, which I consider to be the cream of the crop, but I was told that the reason Van's originally sent the narrow deck versions to everybody and was telling them to just reclock them is that the prototype originally had a narrow deck engine. Maybe that is just urban legend. It doesn't really matter.

This avocation has a foundation of new stuff learned everyday. Nobody expects anyone to know everything.

[rvbuilder2002]

Originally Posted by woxofswa

Scott, no disrespect to you or Van's, which I consider to be the cream of the crop, but I was told that the reason Van's originally sent the narrow deck versions to everybody and was telling them to just reclock them is that the prototype originally had a narrow deck engine. Maybe that is just urban legend. It doesn't really matter.

This avocation has a foundation of new stuff learned everyday. Nobody expects anyone to know everything.

The difference between the wide deck and narrow deck version is the pressure output because the two engines have different gear ratios for the gov drives.

That is the reason for two different gov.

Not already having the correct clocking is is unrelated. The manufacturers will set it to what every you desire but it is not practical to stock a bunch of different parts just for different clocking positions, when they can (relatively) easily be changed.

Not urban legend, but not true.
N410RV still has the same engine it had since first built, and it is the same wide deck engine that Van's currently sells to RV-10 builders.

[Dorfie]

Nobody answered this one, so I try again.
Does the MT P860-3 governor work on both wide and narrow deck IO-540's?
Thanks
Johan

[Dorfie]

Vans sells P860-3 for IO-540 engine that they sell, which is a wide deck engine.
Per MT application page http://www.mt-propeller.com/pdf/list_gov_e-1057.pdf
P860-3 is for Lyc IO-360-( ) front mounting, ratio 0.895:1 (top of page 2)
P860-19 is for Lyc IO-540, specifically RV10 mentioned, ratio 0.947:1 (middle page 2), with prop MTV-12-B
P880-21 for Lyc IO-540 (n. deck), ration 0.895:1. (bottom page 4)
P884-3 for IO-540 narrow deck, ratio 0.895:1, (bottom page 5)
P884-5 for IO-540 wide deck, ratio 0.947:1. (top page 6)
P884-20 Lyc IO-540- wide deck, ratio 0.947:1. (4 lines down page 6)
These are all RIGHT hand rotation facing the driving pad (which I assume to be clockwise rotation).
All of these except for the RV10 does not have an aircraft type mentioned.
All of these other than the RV10 does not have a propeller mentioned.
I have not seen a front mounted governor on IO-360, but I am no expert on that.
It seems to me that the P860-3 has the correct ratio for the narrow deck engines. Yet VANS sells it for the wide deck engines that they sell.
Hope someone has more insight into this than I have.
Johan

[Dorfie]

Per MT website the max RPM for P-860-3 is 2420+/- 10. Engine spinning at 2700 with 0.895:1 ratio (narrow deck) will give this gov RPM.
Engine spinning 2700 RPM with gov ratio of 0.947:1 (wide deck) will have gov RPM of 2557 (range 2557+/-10).
If this is correct then using P860-3 on wide deck engine will result in over speed. Could this have resulted in the mechanical failures of governors not covered by previous SB?
Were the engines on which the failures occurred wide or narrow decks?
Just wondering. Might be completely off.
Johan

[Weasel]

Originally Posted by Dorfie

Per MT website the max RPM for P-860-3 is 2420+/- 10. Engine spinning at 2700 with 0.895:1 ratio (narrow deck) will give this gov RPM.
Engine spinning 2700 RPM with gov ratio of 0.947:1 (wide deck) will have gov RPM of 2557 (range 2557+/-10).
If this is correct then using P860-3 on wide deck engine will result in over speed. Could this have resulted in the mechanical failures of governors not covered by previous SB?
Were the engines on which the failures occurred wide or narrow decks?
Just wondering. Might be completely off.
Johan

My engine was a Narrow Deck