In one of the threads referenced above, there was a fair bit of discussion (I didn't find it to be a 'fight'...but perhaps I'm less sensitive than some) on whether the 'dropping RPM/shutdown' technique solved the 'squeak issue' (not resolved) but also in fact was potentially a detrimental practice.
What was missing from that discussion was that there was a specific recommendation from Ken or Vans own proto shop folks who completed the Rotax courses (I forget which) on how to shut down the Rotax engine properly. FWIW their specific directions were to begin pulling back the throttle from ~1800 rpm and, as the rpms dropped, shutting down first one mag and then the other.
For anyone still interested in why that method might be preferred and/or whether it's potentially risky, I'd suggest following up with the Vans guys and hear what they have to say...not that further discussion here can't be useful as well.
Jack
I'll simply restate my position on that and won't comment on it further (to spare the list another tussle about it):
- this staged shutdown won't affect the squeak on way or the other; the sqeaking happens at a _very_ low RPM, right as the engine comes to a stop, well below any sustainable idle RPM. The squeak isn't a problem to begin with so this is a solution to a problem that doesn't exist.
- the hazard is, if it's not done as described, the engine could be allowed to run, if only for a moment, below the minimum permitted idle RPM. With the sensenitch prop it's probably not terribly harmful, but it certainly wouldn't do any good either. The engine goes to TBO and beyond with the simpler method anyway, so I don't see how it's a bad practice.
So IMO, all this stuff does is just shorten the walk to the rubber room for the owner/op and offers no visible benefits to the engine. The engine will be enjoyed much more with these two non-problems crossed off the list of concerns carried around in the pilot's mind during flight.
That's my story, I'm stickin' to it,
, and shan't mention or follow up on it again
LS