Love those full scale snaps.

Yep...if we had wing loadings like that we'd get great pitch departures too . The Suk's seem to have more (departure) than any other plane though.

Loved how he pushed over the top...around 1:30 (exiting a down 3/4 loop) and immediately entered the 1-turn spin. That was the tighest little radius I think I've ever seen!

Same flight, in-cockpit.

http://www.youtube.com/watch?v=W4YdMXgbJso

Originally Posted by Pistolera

Loved how he pushed over the top...around 1:30 (exiting a down 3/4 loop) and immediately entered the 1-turn spin. That was the tighest little radius I think I've ever seen!

Almost looked like the airplane was still travelling upward a little after he pushed hard level. Guess that's one way to avoid settling into the spin. Very compact spin entry!

Originally Posted by JLeyland

Love those full scale snaps.

Every time I see a monoplane do a snap, I'm reminded of how much more I like watching biplanes do snaps...good clean snaps anyway. The snaps in the video were flown with very large initial pitch displacements in order to clearly present the initiation of the snap, and to ensure the judges are convinced the airplane truly snapped, rather than the pilot doing a cheated 'pull and roll' that some monoplane pilots have been known to do in competition...and have often gotten away with due to the aileron roll rate of the monoplanes, which can equal or exceed the snap roll rate. Biplanes are just the opposite - the snap roll rate is far higher than pure aileron roll rate. My Pitts S-1S rolls about 180 degrees/sec on aileron alone at max straight and level speed. At 110-120 mph (typical snap entry speed), aileron roll rate is around 120 deg/sec. A good clean snap roll at these airspeeds will hit 400 deg/sec. This means the biplane lets you get away with nothing on the snap recovery.

The monoplane guys are all applying full aileron into the snap, which gives you a bit of cheat potential when it comes to stopping the snap cleanly. The last 30-45 degrees or so of rotation can be all aileron, and after banging the stick neutral, it appears the snap stops like hitting a brick wall. As long as the airplane does snap initially, it's hard to notice this small cheat.

In the Pitts, since the snap roll rate vs. aileron roll rate is about 3:1 at typical snap speeds, this aileron cheat will be obvious if you undersnap a little and attempt to complete the rotation with aileron alone. The large reduction in roll rate at the end gives it away. IMO, there's just something much more pure and honest about a nice clean snap in a Pitts. Not saying lots of monplane guys don't do nice clean snaps, but since monoplane ailerons can cover up a bit of slop in the recovery, I just really love the sight of a biplane doing a "brick wall" precise snap stop.

Yes, but as I recall (at least with the SU-29) the Suk's require a pretty good pitch departure to snap nicely. Also, in my Pitts S1-T I always used full aileron in the direction of the snap, whether pos or neg....it just helped make quick and clean snaps with as little energy loss as possible.

Originally Posted by Pistolera

Yes, but as I recall (at least with the SU-29) the Suk's require a pretty good pitch departure to snap nicely. Also, in my Pitts S1-T I always used full aileron in the direction of the snap, whether pos or neg....it just helped make quick and clean snaps with as little energy loss as possible.

Yeah, I use in-snap aileron during snaps also, but in my experience, this aileron does very little to increase rotation rate if you hit the snap properly. IMO, it mostly gives me a very slight bit of cover if I under rotate slightly...but again, that benefit is limited due to the differing roll rates that I mentioned before. I've heard two schools of thought on the in-snap aileron use - one is that it increases the rotation a little due to the one unstalled wing acting normally. I've also heard it said that aileron deflection during the snap is really just "streamlining" of the ailerons with the snap rotation, reducing drag a little. Not sure which (if either) is correct, as I don't notice much difference. I think monoplanes gain a lot more from aileron use during snaps than biplanes do.

I've seen a lot Suk snaps, and these are some of the most exaggerated pitch ups/downs that I've seen. I think this large pitch displacement comes at the expense of a quick and clean snap. I've seen significantly faster snap rotation in a Sukhoi than those here, but the IAC judging criteria make no allowances for how much a snap is "buried", or how clean and fast the rotation rate is. As long the airplane snaps without question and stops accurately, there are technically no extra points for how clean and fast the snap is. I think international judging standards are likely a little different from regional IAC contests. In IAC, I've seen some judges mark down for "buried" snaps on scoresheets, even though there's nothing in the IAC rules that allow for that. I really have no knowledge with how snaps are judged internationally. But from this WAC video, it appears they like to see lots of pitch displacement, and minimally "buried" snaps with quick and clean rotation do not influence them.

The quickest and cleanest Pitts snaps come from very little pitch displacement. I once got a zero from one judge (didn't stand) for "no snap", due to this issue. So even in the Pitts, when roll rate alone should make a snap obvious, many judges still want to see a large pitch change, which I agree with, since roll rate issues require specific aircraft knowledge, which should not be expected of judges.

Originally Posted by Pistolera

Yes, but as I recall (at least with the SU-29) the Suk's require a pretty good pitch departure to snap nicely.

Heh.. they do, but not THAT much. He was cheating pretty clearly to me. Snap rate doesn't increase so much with aileron as they just give less drag and don't slow them down. I've snapped the Su-29 without using any aileron and I can actually feel the stick being pulled into the snap. Mamistov put in a great flight for sure, but I didn't care for his positive snaps all that much.

Well he's the world champion for whatever that's worth!

Very reminiscent of the unlimited field snaps at the TAS anytime Peter Wessels was in the chair.

Originally Posted by JLeyland

Well he's the world champion for whatever that's worth!

Actually John (or Jon?) a Frenchman won it this time. Women as well.

And regardless of how they snap, Ijust love watching good precision aerobatics.....just like you fly too

Here are some monoplane snaps by another world champion that I really dig. Never seen anyone do them better.

Aerobatics RENAUD ECALLE Tribute - Free Programme 2010 - Voltige (7 min 28 sec)

ABSOLUTELY! Although there ARE a couple PZs in that flight by my eye, but they didn't get scored that way.

Renaud was freaking brilliant! This should be required viewing for anyone interested in acro in any genre.

Originally Posted by Shaker

ABSOLUTELY! Although there ARE a couple PZs in that flight by my eye, but they didn't get scored that way.

Renaud was freaking brilliant! This should be required viewing for anyone interested in acro in any genre.

Agreed, some snaps were suspicious. But there's always the benefit of doubt. Renauds rolling circles were in the league of their own. Rolls were so fast, that even a seasoned jugde had to really work to keep up with it. I once had the opportunity to see Renauds 4-min freestyle in Paris Air show 2009. It was quite spectacular.

Such a loss. I would've loved to see him fly