"Perry J. Mick" wrote:

Reminiscent of last year?s Teledyne Continental crankshaft
problems, Textron Lycoming recently released Service Bulletin (SB)
549 highlighting a ?potential metallurgical condition? on crankshafts
installed in four-cylinder 360-series engines or shipped as spare
parts. The suspect crankshafts were shipped from the Lycoming
factory May 1, 1997, through April 30, 2000, and are listed by serial
number in the SB. Lycoming requires that affected airplanes
undergo nondestructive testing at one of several Lycoming-certified
facilities listed in the SB, and will extend warranty coverage for cost
of the required inspections through October 31 of this year.

--
Perry Mick
Duckt N7XR
http://www.ductedfan.com

An aircraft piston engine is a high strung beast if there ever was one. The

least little

defect can be disastrous.

Paul Lamar

I wonder if they both went to the same (incompetent) supplier?
The primary cause of "high strung" behavior is keeping the motor as light
as they can.  Increase the main brg diam by 0.5" and don't drill out
the centers and I bet they'd be bulletproof, and REALLY heavy.
Light is hard, and I'll be nobody has ever done a good FEA of any of
the primary parts in these old designs.  One of the common reasons we
do FEA at work is to understand the margins in our designs.  We HATE
surprises, and just because it has never broken doesn't meean you have near
zero margins and a small change by a supplier (sound familar) can put
you over the edge.

Bill
Long EZ builder & pilot
BSME, MSME

 
The AirCraft Rotary Engine NewsLetter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org