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#11
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I never flew an piston engine that will continue to run at idle with a
feathered prop... Way too much load... Denny "Ron Natalie" wrote in message ... wrote in message om... With the propeller feathering at low/no rpm, it must be inspected/repaired. Then the first step in diagnosing a strange "governor" problem is ensuring that the proper amount of engine oil is present at the governor pad. The tooling to accomplish this also makes it easy to check the prop oil supply path from the other passage at the governor pad through the front main bearing to the prop galley in the crankshaft. So how do you explain the engine stalling in addition to the feathering? |
#12
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Thanks for everyone’s help. I was told by my A&P today to swap the governors
from the right to the left engine and take it up to see if the left engine feathers and shuts down. Friday morning IM going to go fly and see what happens. I have about 40 hours on the right engine. Today I also drained the oil and flushed the engine. I cut open the oil filter and found some small metal particles. I used a funnel with a screen when I drained the oil and found no metal particles. I also took the screen off the governor and found no metal particles. When I drained the fluid out of the engine I also found no metal particles. All the cylinders are 80/80. By the way the engine feathered and shut down at 1000rpm,1500rpm,1700rpm, 50psi and oil temp below redline. Thanks for everyone’s help once again and I will let everyone know what happens |
#13
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Hope you don't have two separate, overlapping, problems. Yikes, now it's
both engines !! :-( -- Montblack ("AIR ADVENTURE82" wrote) Thanks for everyone's help. I was told by my A&P today to swap the governors from the right to the left engine and take it up to see if the left engine feathers and shuts down. Friday morning IM going to go fly and see what happens. snip |
#14
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"Dennis O'Connor" wrote in message ...
Piston props (that i have flown) don't feather during shutdown... It's tough to diagnose a problem on a complex system like a feathering, prop without being hands on, and without knowing the details of the feathering mechanism of the model of prop involved, but my initial inclination is still that it is governor or hub, not engine.... Since then I took a quick look at the commanche prop hub, and they have a pair of locks that prevent the blades from feathering when the rpm is below a certain rpm... Those locks are stuck open or damaged... However, the blades still wouldn't feather as long as the engine has enough oil pressure for the piston to overcome the feathering spring... Since he specifically said he had oil pressure at idle I still am very suspicious that the prop governor has an internal leak after it gets hot... snip The last couple of years that I spent "in the business" I was seriously spoiled. All I had to do was walk 75 feet across the ramp to the prop shop w/attached governor overhaul facility. The gov shop had two machines, one kept with pristine "new" oil for checking/setting overhauled governors only, the other with "serviceable" oil, used for ops/function checking as-removed governors. I couldn't run one myself, but saw 'em used quite often. As you would expect, "hot" oil was used when operating the governors. Back to the PA30 in question, I'm pretty sure that the props installed will have compact hubs, opposed to steel hubs (with external blade clamps and external pitch stops). On these props, the locks are internal, working in the sorta the same fashion (weighted plungers w/springs), engaging a notch in piston rod (connects the piston to the yoke that twists the blades) at low/no rpm to prevent feathering on shut-down. As you've pointed out, a recip feathering on shut-down (or feathering causing the shut-down) is not a "normal" situation, neither is the lack of governed oil pressure at low rpm. In this situation, I would have gone next door and asked the prop boys if they could squeeze me in for a "dome job", stopped in the gov shop, look to see if anything was bolted onto the #2 gov machine and borrowed the gov pad plate. Then, with the engine "hot" woulda popped the nose bowl and the gov, installed the plate, used a differential compression tester to check the gov-to-prop circuit, plugged it, hooked a direct reading gage to the gov oil supply port and run that sucker noting the pressure supplied to the pad. Pretty simple then to carry the removed gov over and beg the gov dude to throw it on the machine, if the machine had been "warmed up" that day, would take about five minutes to wring the gov out. Depending on hangar space, would probably then yank the prop to get the dome pulled off and the locks looked at, addressing any other issues discovered as needed. E.T. to properly diagnose 2 hours skipping no aspects of "normal" propeller/govenor ops. Repair time/cost variable as to what was found. Have had various incidents over the years where a prop feathered on shut-down. 9 times out of 10, a very careful re-start and shut-down would result in normal ops. Often would happen again shortly thereafter. If it feathered "twice" the prop got repaired, end of story. BTW, I wouldn't bet that an engine would continue to run at a "normal" idle setting with the prop feathered, but then again I've never had the opportunity to try it... TC |
#15
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Hi everyone today I took my pa30 up and went around the airport once then
landed and none of the engines feathered and shut down. So i went up for about an hour then landed and BOTH engines feathered and shut down??????? We are still trying to find out what this is. |
#16
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Both engines were holding 42psi so when we checked them yesterday.
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#17
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I just talked to the prop guy and he told me that the stop pins in both props
were very sticky and hes going to clean and lub them up. Also i had the governor checked and it needs an overhaul. |
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