More failure trend. This needs attention. That's three in a few weeks.
http://www.vansairforce.com/community/showthread.php?t=140840
http://www.vansairforce.com/community/showthread.php?t=140840
Joel,
Sorry to hear of your issues and damage. Hope you get it resolved and back in air soon as I know your RV10 is utilized frequently.
Question, Do you think it is possible the weights interfered with the housing prior to catastrophic failure? Do you think it is the reason for the weight snapping the ear of the retaining pin because the weights interfered with the housing?
My governor is the 860-4 mated to an IO 320 with a Hartzel prop. Since I'm at 5 years and the recommended overhaul is 6 years according to the folks at MT I spoke with, I decided to send it for overhaul. At $550, is seems prudent, given recent experiences. It will be interesting if they find anything. I'm sorry you all have gone through the malfunction and resulting troubles but am grateful for you sharing your experiences.
That is considerably less than what I just paid. Who are you using?
I called MT directly in Deland. They gave me a quote of $550 for overhaul. I also called American Propeller in Redding, Ca and they were $900+ for the same service..
My governor is the 860-4 mated to an IO 320 with a Hartzel prop. Since I'm at 5 years and the recommended overhaul is 6 years according to the folks at MT I spoke with, I decided to send it for overhaul.
The manual that Dan provided a link for seems to indicate there is no TBO
erich
As a result of the reported failures of MT P-860-3 prop governors posted here in the forums, Van's has contacted MT-Propeller USA (the supplier of the gov. that have been sold by Van's). Van?s has supplied to MT any available information on those failed governors that were sold through Van?s. ie: Date of delivery, Time in service etc.
MT USA has indicated to Van?s that they are currently acting on those reports. Rather than having information flow from multiple sources (with the confusion that can often cause), Van's is referring customers directly to MT-Propeller USA to obtain assistance in determining if their governor is at risk of failure. MT indicated to Van?s that they are happy to work directly with our customers regarding this issue.
Yes there is a TBO. Its 2000 hours and/or 72 months.
MT Propellers
ATA 61-20-48 Operation and Installation Manual
Hydraulically Constant Speed Governor
P-8( )( )-( )
Link: http://www.mt-propeller.com/pdf/manuals/e-1048.pdf
Specifically, page 4, states in part:
1.1.1 Overhaul
Overhaul is a periodic process and contains the following items:
- disassembly
- inspection of parts
- reconditioning of parts
- reassembly
The overhaul interval is based on hours of service (operating time) or on calendar time.
At such specified periods, the governors should be completely disassembled and inspected
for cracks, wear, corrosion and other unusual or abnormal conditions. As specified, certain
parts should be refinished, and certain other parts should be replaced.
For overhaul interval for the governors please refer to Service Bulletin 1
MT Propellers
Service Bulletin No. 1 R1
Subject: Time Between Overhaul of Propellers, Governors and Oil-Accumulators (TBO)
Aircraft affected: All with these Propellers, Governors and Accumulators
Link: http://www.mt-propeller.com/pdf/sbs/sb1r1.pdf
Specifically, Page 10 states in part:
5.2 Time Between Overhaul (TBO) Governor:
Governor: P-8( )( ) - ( ) Piston and Turbine engines 2000 hours 72 months
I called Harzell to inquire about their governor which seem to be the exact replacement with no modification needed. They indicated that theirs has a 2400 hour TBO with no calendar time limitation. If the cost of an overhaul is around $800 which some have been quoted for, it seems to make sense to switch to a new Harzell, at lease this is what I would do.
Yes, I am based in Placerville, looks like you are also close by. Will send you a PM.I see you are in SAC?
So the engine teardown has begun. As expected, the prop gov drive assembly is toast. What wasn't expected was apparently one of the exhaust valve tappets broke and ping-ponged around. The good news is it doesn't appear that the case has been cracked, but they are going to dye it to be sure -- hopefully I will dodge that bullet. So far we know all of the the valve springs will be replaced and all the other components will be pulled and measured for service limits. I would expect that additional valve train components will need to be replaced. More to follow....
Ouch. What rpm did it hit during the overspeed, and how long was it up there?
3250 for 10 sec. I was flying a missed approach at the time and actually did not know the magnitude of the overspeed until I pulled the engine data log the next day.
3250 for 10 sec. I was flying a missed approach at the time and actually did not know the magnitude of the overspeed until I pulled the engine data log the next day.
Wow - I wouldn't have predicted that 3250 rpm would lead to a failure in the valve train.
Well **** happens, and so far my insurance underwriter hasn't given me a reason to panic--yet. Right now the estimate is north of $21K and that's before they find anything that needs to be replaced outside of the prop.
The worst part for me at the moment is:
A: I now have a 12-hr drive one-way ahead of me to Florida (and then back) next week instead of a 4 hr flight.
B: Yesterday my painter e-mailed me that my slot on the wait list had finally arrived for 19 Sep. Luckily he found someone further down the list to swap with me so now it's Mar 2017.
Todd,
Great news about the insurance, I thought for certain they would tell you to pound sand. I wonder if they will subjucate the claim to MT.
Well I'm not going to jump to any conclusions one way or the other. The tappet failure could be purely coincidental, or perhaps it was on it was already well on its way to failure and the overspeed just accelerated the process--who knows?
My only advice is if you have an overspeed, read Lycoming SB 369L very carefully, and contact your prop and rotating accessory manufacturers for potential impacts. In my case my prop, and 1 of 2 of alternators exceeded specs and had to be replaced. I also went ahead and replaced the 2nd alternator as it was real close to the manufacturer's max limit and as I have an all electric airplane and fly IFR a lot, I deemed it prudent to replace.
Hey Todd, Get your engine back yet? Let us know if you found anything else broke. I have been running the new engine a while now and if I can find time later in the winter I may tear into the broken one.
BTW sure has been quite from MT.