Michel,

The QAC advice was that the GU could not handle the O-200 engine mass. I think enough O-200’s have been installed and successfully flown with GU canards over many trouble free hour so as to indicate that this QAC advice is now disproven.

It is even possible that the GU canard is actually less likely to fail than the LS1 on hard landings. This is not a proven fact, but my own personal opinion.

I think the primary reasons for QAC development of the LS1 canard was to avoid negative effects of contamination. All carbon spars were load tested prior to shipping, so the factory had greater confidence in them, than the GU spars which were all hand laid-up by the builder.

Later, vortex generators proved to be totally effective on the GU and eliminated the contamination problem.

Lots of Q-folks were willing to test these ideas, and then talk about their results (via Q-talk newsletters and this list), That was the key to moving forward on the design and keeping it alive.

Sam has done a great job of keeping that spirit alive with his series of hangar talks.  Thanks Sam!

Cheers,

Jay ….Tri-Q2 N8WQ, 150 hours