IAC Sportsman 2022 Known Sequence

Over about 3 Gs my dead ear starts singing at me and my stomach says "go home." I do six slow rolls every single week, and I swear I am getting worse at it.
 
darrell whitley said:
Darnitt. Lotta G’s.
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Agreed. It ain't an F-15.

Physically my tolerance has reached the point where I don't really notice it. I was really surprised when I looked at the G meter after a few iterations, because it did not feel unusual.

But I don't like the idea of putting that much force on the plane on a regular basis. I am also concerned about other pilots screwing up the 2/4 roll and then pulling through with excess entry speed. In a Citabria rated to +5, there is not a lot of margin for error.
 
Yes. Forward pressure when inverted.

Aileron rolls can be done safely without forward pressure, but start there and practice adding just a bit.

Find a competent instructor for slow rolls. Roll to inverted, and then hold the nose above the horizon.

A split-S from roll entry speed can become very dangerous very quickly. Avoid them!
 
darrell whitley said:
Yes a split S from entry speed, about 20degrees nose up will border yellow arc if you don’t get the power off quickly.
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In a Decathlon you can load it up with G's to stop the speed buildup. With 4.8G in my Decathlon I finished at about 155mph, still in the green arc even with full power.

With a Citabria I would cut power for sure.

I also use an entry speed slower then the book if I can.
 
darrell whitley said:
Yes, starting a roll and falling outta it into a split S.....
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Ah ok. Don't do that.

JK, you'll be fine as long as you have plenty of altitude and get off the power quick. But there have been fatal accidents caused by that reaction, so you really ought to avoid it. Correct recovery from a botched roll is to continue the roll to upright.

Try pitching your nose up a bit when you start the roll. Then keep the nose up throughout the maneuver with correct rudder and elevator inputs.

What entry speed are you using? A little extra speed helps keep the nose up. But definitely don't pull through if you add speed.
 
Yeah, I do everything at 4000' That keeps me safe.. I use 120mph on the rolls.. If the roll goes to a split S I recover to wings level. It stalls, spins just fine..
 
Ed, I don't understand your apprehension with removing power from the equation. The engine is an energy producer, if you need less energy, roll the throttle back as the nose approaches vertical down then ease it back in as you're pulling back up to level.

It's hard to say if that 5 g's you're seeing is the result of a well formed half loop or if you're pulling into the lower half too late. Is there anyone around you that can watch from the ground to see how it would look to a judge?

Also, what did Adam Cope end up saying about it?
 
Cutting power is a reflex among novice competitors who are uncomfortable with speed and G's. Experienced competitors strive to keep full power throughout the sequence (except for spins of course). The reason is that your total energy requirement is defined by the sequence, not the individual maneuvers. If you run out of energy before you finish the sequence, you can't finish without a break. So you want to keep your energy producer running as much as you can. Same reason you should feed in full power during the downline of a spin recovery and not wait until you have pulled out to horizontal.

I was pretty aggressive in starting the pull early in the half loop, and I pulled hard. Some of the excess G is from holding that hard pull and not easing off a bit in the last 1/8 loop. As a result my half loop was probably a bit L shaped at the bottom. I will work on that when I get some ground coaching. I expect an opportunity for that during the week prior to Sebring in April.

I will go back and find it Adam's comments and post them. Most had to do with the subtleties of rudder in the 2/4 roll. That is the challenge here, and the learning point. If you can finish the 2/4 roll without any airspeed increase from your entry speed, the half loop down is no big deal.

The gist of his comments were that at that airspeed the top rudder required for knife edge flight is going to overpower the ailerons. Unless you come off the rudder, you will literally get stuck in knife edge. So you have to toss the nose up during the knife edge hesitation, then come off the rudder to start the second 1/4 roll, but add some rudder back to maintain heading as you approach inverted.

All of that is fine and doable, and teaches you a lot about your plane. But ... while you are mucking about in knife edge, your aircraft is not generating much lift. If your aircraft is not generating much lift, it is descending, and the means speed is increasing, which means the entry speed for the half loop is too high. Hence the issues with G force at the bottom.

I'm confident I will be able to work through this. But from a category creep perspective, I think it was a miscue.

BTW there is a subtext here about sequence creep. The advanced and unlimited guys want more competitors. They are convinced that the leap from lower categories is too steep, and are constantly clamoring to increase the difficulty of Intermediate. Over time, that adds pressure to make Sportsman harder too.

The IAC guys running the show don't really notice, for a couple of reasons. First, most of them are advanced or unlimited competitors. Second, like a frog boiled by increasing the water temperature a degree at a time, the changes have been too gradual for them to notice.
 
Bartman said:
I understand if you're too busy.

For whoever might want to consider participating at contests as a Judge or Judging Assistant, there's a two day ground school. It has traditionally been done in person over a weekend but it was done online last year. Once you've done the class you are required to get a certain number of assists so the challenge is to be at contests and to make sure the volunteer coordinator knows you want to work on the Judges' Line assisting judges. But there are a lot of people trying to log the requisite assists so you might have to attend a few contests to get them all in. Once you've logged enough assists (each time you call the sequence for a judge it's one assist. as they watch the pilot fly the sequence you read the sequence card so the judge knows what they are watching as it's happening. some judges will ask for your input regarding the technical quality of the figures, some won't), you schedule an oral exam and if you pass it you become a Regional Judge first, then you can go on to qualify as a National Judge. It's fun, I recommend it!
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The two day online judging course is this weekend.

Online Intro Course | International Aerobatic Club

www.iac.org www.iac.org
 
Big Ed said:
Cutting power is a reflex among novice competitors who are uncomfortable with speed and G's.
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I can see how you would think that but there is a large group of very experienced pilots with fixed pitch props on their Pitts and other types that will, from time to time, adjust power. Some won't and have grown comfortable letting their engines rev past redline but many will.

It could be that if you pull more, earlier in the half loop, to reduce the radius and create more drag, you will have to pull less in the lower half to finish the figure. a big diving radius isn't required for the figure to look right.
 
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I don't think the 2 x 4 is that problematic. You're coming off Figure 7 at a low speed so you'll be building speed as you draw the line to Figure 8 with full throttle. Do the 2 x 4 when you attain your entry speed that you've worked out in practice. The few seconds you spend rolling about knife edge is not going to create any speed issues. The last time I flew my 8KCAB in this particular maneuver in a Sportsman sequence (with a half roll, not the 2x4) I rolled at about 90-100 mph with full power and pulled through a tight half loop. The exit speed will set you up for a nice big loop and hammerhead for the judges.
 
jstro said:
I don't think the 2 x 4 is that problematic. You're coming off Figure 7 at a low speed so you'll be building speed as you draw the line to Figure 8 with full throttle. Do the 2 x 4 when you attain your entry speed that you've worked out in practice. The few seconds you spend rolling about knife edge is not going to create any speed issues. The last time I flew my 8KCAB in this particular maneuver in a Sportsman sequence (with a half roll, not the 2x4) I rolled at about 90-100 mph with full power and pulled through a tight half loop. The exit speed will set you up for a nice big loop and hammerhead for the judges.
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What year is your 8KCAB? Metal or wood wings? Spades?

My performance with half roll is same as you describe. Half roll at 80, tight half loop, pull 4G, finish at 160. No big deal.

But the 2/4 roll is not taking "a few seconds" in my older wood winged Decathlon with no spades. It takes about 10 seconds, and adds at least 20 mph to exit speed, with a harder pull.

The logical response would be to slow the entry speed accordingly. But, that creates a different problem.

The roll rate from the knife edge pause to inverted seems to be the issue. Adam Cope, the IAC sequence committee test pilot for Sportsman, says at slow speeds the top rudder can overpower the aileron, and the airplane can get stuck. My initial attempts confirm this.

According to Adam, the solution is timing the rudder. Big top rudder in knife edge, come off rudder almost completely to start the 2nd 1/4 roll, then feed it back in at the end to keep on heading before the pull.

I'm going to a chapter camp next weekend and will get some coaching. Should get better insight then.

I'm confident I'll be able to figure it out. But IMO this is a good example of unnecessary category creep.
 
Big Ed said:
What year is your 8KCAB? Metal or wood wings? Spades?

My performance with half roll is same as you describe. Half roll at 80, tight half loop, pull 4G, finish at 160. No big deal.

But the 2/4 roll is not taking "a few seconds" in my older wood winged Decathlon with no spades. It takes about 10 seconds, and adds at least 20 mph to exit speed, with a harder pull.
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Just to get some more data, I watched the Sportsman sequences at the Nationals where I and others flew this maneuver, again with a half roll instead of the 2/4. The Decathlons all take about 2 seconds to complete this half roll, or about 90 deg/sec, at the entry speed being used. So for the 2x4, if we hold the knife edge for 1 second, then the entire roll could be completed in around 3 seconds, in theory. However, to be a little more realistic and give it some breathing room, let's call it ~4-5 seconds for the entire 2x4 half roll if we're nice and crisp.

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. You mentioned you don't have spades. Spades or no, the roll rate of the aircraft is still the same. The difference is the stick force. There's a couple times in my sequence where I put both hands on the stick to make sure I have full deflection. So if you're not doing that, I'd say give that a try to make sure you're using prompt and full ailerons.

The 20 mph speed increase during the roll you mention is concerning. The change in kinetic energy going from, say, 80 mph to 100 mph, translates into an altitude drop of around 120 ft if we use a kinetic-potential energy balance. So if you're losing this kind of altitude in the roll, you're going to get knocked off a lot of points just for that alone. One thing you can try is nudging the nose up just a smidge before the roll. If you're subtle the judges are likely not to notice. Also, be prompt in feeding in forward stick as you roll inverted.

Finally, while this sounds counterintuitive, how about a faster entry into the roll? You're going to roll noticeably faster at 90 mph or 100 mph rather than at 80 mph, so there's less opportunity for altitude loss. On the other hand, you'll end up with more speed at the bottom of the loop. Like I said earlier, my entry is around 100 mph and I exit the loop around 160-180 mph depending on how much I pull, keeping full power. If the next maneuver is vertical (it always is!) I can take advantage of that extra speed and convert it right back to altitude.

These are just my thoughts from my experiences, and I'll be looking forward to see how it goes. Happy flying.
 
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