912 ULS Crankshaft Nut Torque Question

Todd Bailey wrote:

Hi Steve,

For what it's worth, I torqued mine to 219 ft/lb last year and have not experienced any issues.  The locking pin, threads and nut were all fine and alignment was still good.  So far, it has held up for 65 hours.  I used a digital torque adapter along with the biggest breaker bar I could find so that I could control the torque more precisely as I wold not have to strain to get to the value I wanted.  I bought good tools, studied all available documentation, planned everything out and took my time checking each step.  Everything went fine.

I, too, was concerned about the large variation in the torque values presented in the different manuals - which is why I asked for help here.  It seems that Rotax has confirmed the 221 ft/lb value so I am comfortable with it. 

Hope this helps ease your mind a bit.

Did you have to brace the engine or was it just in its mounts?

No, I did not brace the engine.  We did a conditional inspection shortly after and the engine mounts were fine.  Of course, that might depend on your plane and mounts.