RV's won't spin inverted?..Oh yes they will..:D

[sandifer]

If I may be so bold to suggest, maybe you could re-edit the video with captions indicating your control inputs as the spin progresses.

Good idea Damon. Re-edited with description and notes, FWIW.

http://www.youtube.com/watch?v=i3DJlced8gw&feature=plcp

OK, a pull out isn't likely to be any problem with 6 G's available and no structural concern, but it is a perfect set-up for G induced LOC (loss of consciousness) during the pull out. This can lead to 15 seconds or more of unconsciousness followed by a further period of disorientation and confusion - ask me how I know! To avoid this some pilots prefer the push-out

Bill, it's very true that +G effects are more noticeable when preceded by a significant amount of time spent negative. The Intermediate Known had this "problem" a few years ago and didn't involve any spins - just (3) negative lines followed by a 3/4 positive loop down, which caused many folks to grayout...different from LOC. I don't yet have experience or knowledge of anyone LOC'ing (losing consciousness) during a competition flight. But in competition flying, inverted spins are over pretty quickly, and are typically followed by a quick 90 degree pull from vertical to level. Not really much opportunity to go to sleep. The long 3/4 loops preceded by significant -G are more suspect. Plus, the spin is only -1G, so the transition is not very large. There are many more figures in Advanced and Unlimited sequences that provide much larger and longer negative to positive G transitions. But in any case, experienced aerobatic pilots have adequate G tolerance, and I've never seen G-LOC issues in contest flying. The duration of even high G is just not very long. IMO, a simple competition (negative) spin of the 1, 1-1/4, or 1-1/2 turn variety followed by a quick pull to level flight is not going to cause G-LOC in an aerobatic pilot with even minimal G-tolerance, and is not something to worry about. I go slightly gray from time-to-time for a couple seconds, but this is just a slight (and momentary) visual impairment issue, and is really not dangerous. But I've never had a hint of gray doing inverted spins with a pull to level flight.

 

[Bill Dicus]

inverted spins

Hi Eric: You're tougher than I am. I usually fly +6 and -4 G's in the Pitts but I've learned to be careful now. In the past I had many episodes of graying out, tunnel vision and the hearing disturbance that often precedes LOC. As a flight surgeon I got very familiar with those symptoms. Unlike you I've talked to many competitors who grayed out (some fairly frequently) and observed one LOC in competition. I haven't flow competition for many years, but did a fair amount in intermediate and advanced and I think two unlimited contests; stopped unlimited for various reasons including one case of the "wobblies"! Again, thanks for sharing your experience and stimulating a good discussion. As has come out in these posts, most acro pilots feel inverted spins are easier to recover than upright for the reasons stated and it sounds as though the RV recovers readily. Have fun and fly safe.

Bill

 

[sandifer]

Hi Eric: You're tougher than I am. I usually fly +6 and -4 G's in the Pitts but I've learned to be careful now.

I don't think so Bill. If you flew up to Unlimited, you've spent more time than me flying figures that challenge your G-tolerance. I've recently moved to Advanced...or my imitation of it...and have gotten more of those short gray episodes that I described. Unlimited is out of the question these days in my Pitts. I also see around +6/-4, but to me, the sequence and construction of the figures is more of a factor in grayout than pure G transitions. There's a sequence of figures in this year's Advanced Known that's a 180 degree roller with 1-1/2 rolls in to inverted, followed by a push to a hammer. There's quite a bit of negative before the pullout from the hammer, but never go gray here, since the pull to level after the hammer is such short duration. But I tend to go gray during another figure which is a 1-1/4 upright spin with a 3/4 positive loop up with a half snap on top. I always seem to be a little gray by the time I get to the snap after the high-G 3/4 loop up, which is fairly long duration, even though there is no negative G before it. Thanks for all the input...good discussion, and good to have a highly experienced acro junkie here.

 

[Bill Dicus]

Inv. spins

Thanks Eric - Glad to know I'm not a total wimp with the gray outs. I'll look up the current advanced and give it a try as soon as our annual is done. Three or four of us had a hopped up S-1S that we tried in unlimited. I couldn't do the unlimited routines even 10 years ago in the S-2A in a competitive manner, but the S-1S with 200+ HP could compete, at least in local contests. Too bad it's not available any longer! Or maybe it's a good thing for me, anyway. The opportunity to discuss these matters is definitely a good thing..... Appreciate your input. Bill