R985 cowling shake!
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R985 cowling shake!
Here's a question for you. If you have an engine with a rough shake and the cowling is rotating left to right ( 9 to 3 oclock) a bit but still running smooth rather than up and down (12 to 6 oclock) what possible problem do you have and why?
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Re: R985 cowling shake!
The last time my cowling vibrated abnormally, a cylinder had sepated from the crankcase and a forced landing followed. That took place a few minutes after takeoff. The engine was running smooth despite its major dammage. I would take it seriously...
Reading this can not hurt as well:
http://www.tc.gc.ca/civilaviation/certi ... 007-02.htm
Reading this can not hurt as well:
http://www.tc.gc.ca/civilaviation/certi ... 007-02.htm
Flying an aircraft and building a guitar are two things that are easy to do bad and difficult to do right
http://www.youtube.com/watch?v=3Yd_QppdGks
http://www.youtube.com/watch?v=3Yd_QppdGks
Re: R985 cowling shake!
Plug.
"What's it doing now?"
"Fly low and slow and throttle back in the turns."
"Fly low and slow and throttle back in the turns."
Re: R985 cowling shake!
Seen this before on a Beaver.West Coast Swell wrote:Here's a question for you. If you have an engine with a rough shake and the cowling is rotating left to right ( 9 to 3 oclock) a bit but still running smooth rather than up and down (12 to 6 oclock) what possible problem do you have and why?
It's like all of a sudden at a certain RPM right? I had one that did it at between 950 and 1000 rpm.
Tried everything to stop it, engine was smooth and prop was balanced.
The shake went away with a new engine and fresh engine mounts.
My advice, just keep it out of the RPM range where it shakes at all costs. It WILL start cracking cowling parts if left there a shakin' and scares the hell out of passengers.
Matt.
Re: R985 cowling shake!
Check the engine mounts.. Might be time for some new ones...
Re: R985 cowling shake!
Here's a different one for you - do all you radial drivers know what it means if your oil pressure drops from its normal level to a reading a few pounds lower and stabilises there? What is going on?
"What's it doing now?"
"Fly low and slow and throttle back in the turns."
"Fly low and slow and throttle back in the turns."
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Re: R985 cowling shake!
It's bypassing your screen that is full of chunks of engine so big you can read part numbers.
TT: don't care PIC: still don't care MPIC: really really don't care TURBINE: get a life.
Life's never fair, get a helmet.
Life's never fair, get a helmet.
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Re: R985 cowling shake!
Reading the post above mine and maybe it will all make sense to you.... PAY ATTENTION CLASS!buster79 wrote:is that why it shakes? i don't think so.
TT: don't care PIC: still don't care MPIC: really really don't care TURBINE: get a life.
Life's never fair, get a helmet.
Life's never fair, get a helmet.
Re: R985 cowling shake!
A lot of times it's just indication. But it's a good reason to stay near lakes if it isn't.xsbank wrote:Here's a different one for you - do all you radial drivers know what it means if your oil pressure drops from its normal level to a reading a few pounds lower and stabilises there? What is going on?
A lot of radials have seals and gaskets on oil galleries inside the engine that can begin to leak internally and cause a pressure drop. You'll never know because it won't leak on the outside.
Make sure there isn't a bird or something stuck in the oil cooler too.
Matt.
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Re: R985 cowling shake!
We replaced the engine at 850 hours T.T. ..... it doesn't shake any more!! Better safe than sorry.
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Re: R985 cowling shake!
I'm glad the problem was solved even though in a pretty expensive way. Do you have any hint of what the problem was by now?
Flying an aircraft and building a guitar are two things that are easy to do bad and difficult to do right
http://www.youtube.com/watch?v=3Yd_QppdGks
http://www.youtube.com/watch?v=3Yd_QppdGks
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Re: R985 cowling shake!
Quite comen on the dhc2, Use the engine mount numbers from the otter andb your problem is solved. been doing this for thirty years and no more shakes. Try it. Dr.
Re: R985 cowling shake!
Crap. I'm loosing my mind........ We also changed to Otter mounts in the DHC-2 when we changed the engine. I forgot about thatDr. Mcillicuddy wrote:Quite comen on the dhc2, Use the engine mount numbers from the otter andb your problem is solved. been doing this for thirty years and no more shakes. Try it. Dr.

Maybe it was you Dr. who suggested it
