MT P860-3 Prop Gov fail.

[Auburntsts]

Originally Posted by Weasel

My engine was a Narrow Deck

Ditto -- narrow deck for me too

[woxofswa]

Mine was narrow deck as well. One thing this incident has reinforced to me is that incidents almost never have a single point of failure, but are an accumulation of multiple Ernie Gann-esque events of fate and/or folly that culminate into a fail.
Thankfully nobody got hurt and hopefully we can purge this demon from our ranks.

It's still too early IMHO, to make a definitive final determination of what is going on, but in the meantime, EVERYBODY, wide or narrow, 360 or 540, needs to verify that they have the proper unit for their configuration regardless of receipts, catalog listings, kit inventory, or how perfectly it appears to be operating at the moment. An engine builder told me that he was going to "do his part" by attaching a "big *** placard" to every engine shipped from now on, concerning the PG appropriate for that engine.
We are a community of humans and humans make mistakes, but hopefully we learn from them and move on with a broader safety envelope. Manufacturers need to reevaluate their documentation and what they are shipping out and what their vendors are doing with them. Venders need to know what they are stocking, recommending, and supplying to their customers, builders need to know what their exact needs are, and tech advisors, DARS, and mechanics need to be keenly aware of gotchas. Trust but verify.

[Weasel]

I called MT-USA yesterday and talked a while. There is no differance in any of the P-860-XX governor parts. They all have the same weights, springs, drive rotation, etc and are for pressure to increase pitch props (non-counterweighted). The dash number is for the clocking of the actuator arm position which can be changed in the field, and for the maximum RPM speed whitch also can be changed by a certified shop...he told me how its done and its not rocket science. So as long as if it is set to hold ~ 2700 RPM at max pitch it will work. If not a few changes will make it work. My gov. was set to hold the correct RPM when I installed it new right out of the box. This is why van does not stock a lot of different governors. They can be modified to work on many different applications. He even said the max RPM can be changed some by changing the stop set screw in the field.

[Aggie78]

Did MT indicate when they are going to release the new Service Bulletin with the expanded listing and scope of affected units?

Sometime this week? This month?

I'm not flying the aircraft until I do or do not know if I have a governor with a problem and what the planned SB release date would be nice to know for those of us that have taken this step.

I'm trying to hold off on being 1 of 10,000 calls lighting up their phone system inquiring about it...if the info is going to be put out pretty soon.

Nothing on any of their websites so far...

Thanks.

[BillL]

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

A 10 friend ordered his engine (new wide deck) and MT gov from Vans. First flight in May. The RPM was ~200 rpm low. 2500ish RPM. RPM should be checked on first flight, or before.

[civengpe]

Rob,
Last week, I was promised it would be published yesterday...

[Michael Wellenzohn]

Originally Posted by BillL

A 10 friend ordered his engine (new wide deck) and MT gov from Vans. First flight in May. The RPM was ~200 rpm low. 2500ish RPM. RPM should be checked on first flight, or before.

There is however no problem operating the -10 with 2500RPM I have to do this due to noise restriction as standard since Sept. 2013. Max RPM should be checked before first flight like high speed taxing.

Regards
Michael

[BigD]

I received this correspondence from MT this morning, FWIW:

Thank you very much for your message and information.

As fast as possible we will release SB31.

The reason for SB31 is that during operation a flyweight assembly could became loose

The damaged flyweight assembly will result in an overspeed or underspeed condition.



Affected are all governors which are manufactured between April 2010 until July 2013 and which are installed on experimental direct drive engines modified with electronic ignition and /or higher compression piston.



So your governor has the S/N 14G095-G (Manufacturing year 2014) is not affected from SB 31. You can go on with flying.

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 <tel:%2B49%28%200%20%299429-9409-44>

fax: +49( 0 )9429 - 8432 <tel:%2B49%28%200%20%299429%20-%208432>

www.mt-propeller.com <http://www.mt-propeller.com>

[Walt]

Originally Posted by Michael Wellenzohn

Max RPM should be checked before first flight like high speed taxing.

The usual result of a high speed taxi test is an unintended first flight

[Weasel]

Originally Posted by woxofswa

Mine was also a BPE narrow deck that states "built to D4A5 specs".

I chose low compression 8.5 cylinders over future fuel concerns. I wanted a cruise motor, not a race motor. Data plate states 260 hp.

I seem to recall an issue years ago where Van's was shipping "narrow deck" PG's to wide deck owners who were being told to simply change the clocking.

Originally Posted by woxofswa

Bendix 1200's for me.

Originally Posted by Auburntsts

Nope--Slick retard breaker mag with Slickstart on the left, Slick plain on the right

Originally Posted by BigD

I received this correspondence from MT this morning, FWIW:

Thank you very much for your message and information.

As fast as possible we will release SB31.

The reason for SB31 is that during operation a flyweight assembly could became loose

The damaged flyweight assembly will result in an overspeed or underspeed condition.



Affected are all governors which are manufactured between April 2010 until July 2013 and which are installed on experimental direct drive engines modified with electronic ignition and /or higher compression piston.



So your governor has the S/N 14G095-G (Manufacturing year 2014) is not affected from SB 31. You can go on with flying.

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 <tel:%2B49%28%200%20%299429-9409-44>

fax: +49( 0 )9429 - 8432 <tel:%2B49%28%200%20%299429%20-%208432>

www.mt-propeller.com <http://www.mt-propeller.com>

Anyone care to venture why they mention electronic ignition and high compression. The failures here do not support the remark.