IAC Sportsman 2022 Known Sequence

jstro said:
Regarding Decathlons, metal spar wings do roll faster but only about 10% faster, according to American Champion. So I don't think that this is a strong factor to consider.
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From comparing footage of my aircraft to that posted by others, I think the difference is greater, perhaps on the order of 50%.


I have flown the maneuver repeatedly, alternating between a half roll and a 2/4 roll for comparison. There is a significant difference.
 
I have only flown one metal spar Dec - it does feel quicker. My big deal is slow rolls, so I do not need quick.
I note that the metal spar airplane - a 150 C/S - is also more sensitive in pitch, and faster in cruise, while burning slightly less fuel.
 
i think it has more to do with the rigidity of the metal spar wings and the tendency of fittings to give against the wood after years of being loaded and unloaded. OPINION, as Bob would say! 😁
 
Bartman said:
i think it has more to do with the rigidity of the metal spar wings and the tendency of fittings to give against the wood after years of being loaded and unloaded. OPINION, as Bob would say! 😁
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Yeah, rigidity is what the engineering FAQ on the ACA site mentions as being the reason for the slightly better performance.
 
Big Ed said:
From comparing footage of my aircraft to that posted by others, I think the difference is greater, perhaps on the order of 50%.


I have flown the maneuver repeatedly, alternating between a half roll and a 2/4 roll for comparison. There is a significant difference.
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Your roll rate does seem slower than the rolls I found on video, but I don't know your airspeed so I can't really say if it's unusual or not. I found some video of me flying an older wood spar 8KCAB and that plane took about an extra second to complete a full roll than my current airplane. So there is a difference, not too much, but measurable.

I did notice that your roll almost came to a stop when you hit about 60 deg bank. I know your concern is the 2x4 instead of the full roll, but perhaps that is a part of what's going on. You'll get points taken away for inconsistent roll rate, so that's something to take a look at. Are you going full top rudder at that point? That might cause the roll to hesitate. I don't use a lot of top rudder on the initial knife edge since adverse yaw help to bring the nose up anyway, but I think I use about half rudder travel or so.
 
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Got up again today and worked on the 2/4 Split S some more. It's just ugly. I am initiating the 2/4 roll at 80 mph and finishing the roll phase at 110 mph. Even with a HARD pull through, am pulling 5G and finishing at 180 mph. IMO that is excessive and unnecessary in Sportsman. Will continue to refine my technique, with a focus on keeping the nose up. But the confounding part is the 2nd 1/4 roll after the knife edge. ANY top rudder drastically slows the rate of roll. But without top rudder, the nose starts to fall through before I can get the wings over enough to accomplish anything by pushing.
 
After a few more sessions, I'm starting to get the 2/4 Split S to a manageable state.

The key is the second quarter roll. Put in full top rudder during the knife edge, but then completely relax the rudder as you start the quarter roll to inverted. If you have any rudder at all, it will counteract the aileron and you will get stuck in knife edge flight. Your nose will drop and you will pick up speed.

With no rudder, you can let the nose fall a bit as you roll until you are inverted enough to push. Some rudder is needed at the end of the roll to get it back on heading.

With that technique, I was starting ihe 2/4 at 80 mph and finishing at 100 mph. With a full deflection pull, I finished the half loop at about 160 mph and under 4.5G, which is fine.

Going to an IAC chapter training camp tomorrow. Hope to get some good coaching.
 
Had a good time at the camp. Got 2 sessions in the box with 4 total flights. Got some good pointers, especially about positioning and presentation. No magic answers on the more challenging maneuvers, but some techniques to attempt. One of the guys had been a national team member for many years, so he gave a lot of insight on competition strategy. Basically, accept downgrades on low value maneuvers to set yourself up better for the more difficult maneuvers to follow.

His advice on the Immelman and Split S is don't use rudder in knife edge. Not enough airspeed to get any benefit, and the knife edge attitude dumps a ton of energy. Pitch the nose up a bit and unload, then use the zero-G float to roll it at slow speed. Dunno about that, will have to try in my plane and see how it flies. Could be he is more used to Sukhoi's and Extras.

His 2 best pieces of advice are to keep a journal, and carry a practice card. Eg right after every flight, jot down observations and areas for correction. Then on your next practice session, review the journal and make a card with maneuvers to practice and improvement points to focus on.
 
been in training for work, parachute pack is expired, plane's been sitting! glad you're moving it along Ed, go make us proud in April!
 
Bartman said:
been in training for work, parachute pack is expired, plane's been sitting! glad you're moving it along Ed, go make us proud in April!
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Thanks for the reminder, need to check my pack date for the upcoming contest. What is it, 6 months?
 
Argh, totally forgot about the chute! Just checked and I am going to be one week out of currency for the Sebring contest. Gotta get that done TODAY. And of course the rigger just told me he is leaving early.

Have been getting a lot of good practice in. The 2/4 Split S remains problematic, but is doable with power as long as you don't let the nose drop at all during the roll.

Positioning can also be a bit tricky. If you do not traverse the box between the spin and shark's tooth, you spend the rest of the time jammed up against the upwind boundary. That can be fixed somewhat by extending the S&L between the first Immelman and the 180 turn. Also, that turn provides very little crosswind correction, so anticipating drift and adjusting entry point will be needed.
 
My first competition went well. Took first place in Sportsman, though I would not make too much of that. Most of my competitors were new or returning after a long break. I was the most experienced so, long break notwithstanding, I had the best idea what to expect and how to prepare for it.

Winds were a big factor. For most of the contest, we had a 20mph wind at a 45 degree angle to the box. That was an advantage for me relative to the other folks, since I had seen that before. If you don't know the wind and have a plan, it will blow you out of the box or over the judges. If you can compensate for the wind to keep yourself centered on the judges at a reasonable view angle, it will pay big dividends on scoring.

Oh yeah, and 20mph wind in the box means 15mph crosswind on landing. That got quite sporting, since every single competitor was in a taildragger.
 
Really like this thread. The 2/4 roll Split-S is back in the proposed 2024 routine. I've never practiced it (as I only started practicing the 2023 routine). I'll try Bart's suggestion first (90 turn to knife edge, then turn back) first. In the 7 series - we simply don't have the G and speed margins as the 8 series plus dealing with a slower roll rate. I hope this gets taken out of the final published routine ... didn't they get enough complaints about it in 2022?
 
When are you back in the area Laszlo? I was speaking with the owners at an airport just west in PA about a practice session and they were happy to have us. The location of the box is excellent for giving/getting feedback.

Bart
 
Bartman said:
When are you back in the area Laszlo? I was speaking with the owners at an airport just west in PA about a practice session and they were happy to have us. The location of the box is excellent for giving/getting feedback.

Bart
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Wasn't planning on taking the Citabria down till Thanksgiving.
 
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