Group,
I have been very quiet about my accident because of all the legal stuff coming at us from all directions, but I think I should add to this conversation about the seriousness of the situation. As Bob P. and Bob R. have stated, this is pretty serious stuff. I had 98 hours on a Penn Yan overhaul and new propeller when my crankshaft broke in the radius behind the crankshaft flange – just like the Malibu failure – oil everywhere, cowling chewed up, hole poked in the top of the right wing, hole poked in the right side of the fuselage and the right elevator and stabilizer cut off just outside the outboard hinge for the elevator. Like I said – pretty serious stuff.
Like Bob R., I chased the vibration from day one and did all of the things that you normally do for vibrations: Dynamic balance of the prop (two times), changed engine rubber mounts, changed hoses because I thought they were too short, looked many times for things that could be touching things they shouldn’t. We talked with Hartzell about the vibration and their recommendation was to try rotating the prop 180 degrees (no change). Just like Bob R., we did all of these things while we were actively flying the airplane. It was a very subtle vibration – not bad enough to stop flying. People who flew in our plane said they didn’t notice any vibration, but I could always feel it.
Point of all this conversation is that if - - if you feel any vibration, it needs to be investigated. Because the end of the crank is pressurized with oil, you should make it a preflight check to see if there is any oil leaking anywhere behind the propeller. I’m just thankful that Bob R. decided to do a dye penetrant check on his crank when he did the prop rotation!
I personally know of another IV-P owner who has had a vibration from the very beginning and will be stressing the need to check things a little further after what Bob R. has found. His propeller is the full-feathering Hartzell model.
Our trial will be in October (almost 4 years later), so maybe after that I can answer questions a little more freely. You just can’t believe how things you say and do can be twisted so many different ways. When doing something to your plane, just remember……..”there is not a problem until there is a problem.”
Tailwinds,
Ed Smith
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Bob Rickard
Sent: Monday, July 22, 2013 1:43 PM
To: lml@lancaironline.net
Subject: [LML] Re: Potential Problem-Engine Vibration
I will attempt a reply here to Barry and others who have this combination:
1. you have this combination of engine / prop (in any airframe, I've spoken to non-Lancair folks that have the same issue)
2. you have an engine vibration that normal methods can't solve (dynamic balance, motor mount change, etc.)
3. you have a vibration that changes with RPM or comes and goes over the course of a long flight
Then I suggest you remove the prop and do an eddy current / dye penetrant check of the prop flange. Especially if you have been living with this issue for a while (like I did), thinking it is an annoyance. It doesn't feel dangerous, just annoying. But it may be something bigger. I'm glad I didn't let it lie any longer.
Thanks for the heads up. Not quite sure what I will do with the information.
It seems to me that when Ed Smith had his "incident" there was some discussion on LML about similar crankshaft separations in the original Malibu engine / prop combination that our Lancair set-up is based upon. I even recall seeing a photo of the front of a Malibu with no prop. Instead it had a gaping hole in the crankshaft showing where all the oil leaked out. There may be additional information from the FAA or Continental if you add in the Malibu fleet.
Barry Knotts
LIV-Ps, N4XE and N24XE
On 7/21/2013 11:54 PM, Robert R Pastusek wrote:
Gentlemen,
This is an alert for a potentially serious problem with the Continental IO/TSIO-550 engine/Hartzell 78” Scimitar propeller combination
Thanks,
Bob Pastusek
For LOBO