Has anyone actually flown in IAC competition in a Citabria?

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Michael Panek

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I have a 7KCAB and am considering flying my first IAC contest in Primary. Anyone out there got any experience doing that in a Citabria? And, how was the performance ( break in sequence to climb, etc.)?
 
I prepared in a 7KCAB. It seemed to do fine. When my turn came up, the guy who owned the Citabria pointed to a Decathlon and said “go for it - Citabria is broken.” That was my Decathlon check out. Third place. They liked my vertical lines. Beat a couple Pitts and a Stevens Acro.
 
Mike, I have a 7ECA and I am planning on competing in Primary this year. With a 7KCAB you should be able to do the Primary sequence without a break unless of course you just want the break.
 
Thanks Bartman
Please keep me informed of your results.
 
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My sequence was in 1976. They change year to year. Back then you simply drew a straight line, then executed the next maneuver. I think my points came from the down line after the 3/4 spin. No need to extend any lines - just hesitate long enough so the judges could see it.
 
I have competed 4 or 5 times in Sportsman in a Decathlon 150 CS. IMO it is winnable, and I never felt performance was a hindrance.

I don't know the 7KCAB well enough to opine how it might fare, but other than roll rate it should be close in performance to an 8KCAB with 150.

I never had to take an altitude break. The reference aircraft for Sportsman is a Citabria, and the sequence is tested every year to confirm it can be performed without a break in that aircraft.

WRT how long to hold your 45 up line, the answer is as long as possible, in order to milk every last bit of energy out of it.
 
Bartman said:
Mike, I have a 7ECA and I am planning on competing in Primary this year. With a 7KCAB you should be able to do the Primary sequence without a break unless of course you just want the break.
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Bart - which competition are you planning to attend?
 
So I'm planning to enter and do the Primary this year as well with my '69 7ECA: aiming for the Green Mountain Acro contest in Vermont July 16-18.
It would be great to share notes, I'm still working on linking the sequence together. In particular, I'm experimenting with power settings. I've already determined that it's easy to redline the engines! I'm thinking of setting power at 2600 RPM, once at 140mph, and leaving it there for the 1/2 cuban, loop, steep turn, and roll (pretty much the whole sequence after the spin). Unless I botch something up, this will ensure I won't redline on the pull up, and don't have to be distracted with adding full power on the climb, pulling back on the down line. I suspect however that this will result in poorer looking loops ... What are others doing with the fixed pitch props, in terms of power settings? It's easy enough to apply full power going up into the loop, but I then have difficulty finding the right setting coming down, leveling it, and pulling up into the next maneuver, without carefully monitoring the RPM. This distracts from looking out and ensuring you're straight, etc.
For the primary, you shouldn't need a break, even with the 115HP. It does mean doing the slow roll at the end below the 120MPH recommended airspeed, I've been therefore practicing the roll at 100MPH.
 
I agree with you about the power settings. It is very easy to over speed the RPMs, even going into a pull up after a dive. I think flying a Citabria (with fixed pitch prop) becomes more of 'energy management' than brute power. Like my daddy used to say, "The best thing to spend money on for the airplane to get better at acro is put gas in it's tank and fly!" He learned that from Bill Herendeen. I will eventually get the timing and "flow" of the sequence. I am looking forward to hearing from others success and learning moments.
Thanks for the post...
 
I don't have any experience with fixed pitch props. However, the procedure you describe for setting max rpm is exactly what the Goulian textbook recommends. Pitts S1S is always a threat to win in Sportsman, and that has a fixed pitch, so it's doable.

One key point: the judges don't have an altimeter. They judge by mark 1 calibrated eyeball. Your plane is larger than the planes they are used to judging, so they will tend to estimate your altitude as lower than it really is.

That has 2 implications. First, set your floor at 2K, not 1500. Judges are quick on the trigger to penalize a new competitor for busting the bottom of the box, because safety. OTOH they are unlikely to ding you for being too high, unless it is ridiculous.

So, enter the box as high as you can, with as much speed as you can. On primary, enter at a speed and altitude that will put you at or just above 3500 for the spin entry. Figure out your recovery altitude for the 1.5 turn spin. You should not lose more than 100 feet or so on each of the remaining maneuvers. You can actually gain altitude on the cuban by shallowing up the 45, though you'll get dinged on points.

One thing that will help with energy, and thus altitude: on the spin recovery, apply throttle in the vertical downline on recovery. Don't wait until you pull horizontal. The sequence is:
- spin entry
- opposite rudder 1/3 rotation from desired heading
- stick forward on desired heading
- push to set downline
- add power
- pull to horizontal

A big part of competition is learning positioning in the box relative to wind. The box entry direction will be chosen so you have a headwind component. When driving into the wind, hold level and push to the edge of the box. When flying away from the wind, don't dawdle or it will push you out.

Very important: on the 180 turn, TURN INTO THE CROSSWIND COMPONENT. Talk to other pilots, figure out which way the wind is carrying you laterally, and use the turn to adjust back to the center of the box. That is especially so if the wind is carrying you towards the judges.

Get there early enough to fly a practice run in the actual box. Those are usually done the afternoon before. I failed to win a contest that I could have won because I got misoriented by multiple runways. Practice run helps you identify visual sight cues for box position.

If you are at 100 mph for the roll, you are probably not flying the loop correctly. On a good round loop, you should finish at the same airspeed as you entered, and within 50-100 feet of entry altitude. Usually the error is not relaxing the pull at key point to float over the top. Called pinching the loop.
 
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Thanks Ed - I was calculating on 100mph given the pause after the loop, the 180 turn, pause, then slow roll. Haven't perfecting the sequence link here yet, but I figured the 140mph will erode through all of that to 100mph. With 115HP - the 7ECA slows drastically from 140mph flying level! I'll work on this to see what I end up with, but was considering 100mph as worst case. Thanks for the tips on altitude and the spin. I've yet to get the timing right to pull out of the vertical from the spin so I end up with 140 (as opposed to 120 or 160).
 
volvo164 said:
Thanks Ed - I was calculating on 100mph given the pause after the loop, the 180 turn, pause, then slow roll. Haven't perfecting the sequence link here yet, but I figured the 140mph will erode through all of that to 100mph. With 115HP - the 7ECA slows drastically from 140mph flying level! I'll work on this to see what I end up with, but was considering 100mph as worst case. Thanks for the tips on altitude and the spin. I've yet to get the timing right to pull out of the vertical from the spin so I end up with 140 (as opposed to 120 or 160).
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Ah ok, got it. Well, you don't need to pause for more than 1 or 2 seconds between figures, unless longer needed for positioning. So if you are bleeding energy due to drag, you can shorten those legs up. Use your timing on the spin to control your positioning for subsequent figures. Eg pull 45 up, level off at MCA, and drive it all the way to the front box edge before spinning. That gives you room to shorten the pause between the cuban, loop, and turn, and still be far enough upwind to complete the roll before exiting out the back of the box.

All this depends on wind, of course. A firm headwind is more challenging than calm conditions. Surprising how fast you move thru the box at 140 mph with a 10 mph tailwind. The only time that is a factor on primary will be between the spin and cuban.

The key to recovery speed is not being afraid to pull firmly. If you are "gentle", speed continues to build up. If you load up to 4G and hold it, speed buildup will stop.
 
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Judges understand and respect the challenge of flying the sequence in our aircraft, and will reward a good effort. That is especially so for an underpowered aircraft. If you can manage energy to complete the sequence unbroken and stay in the box, they will be impressed. You will learn a hell of a lot too.
 
Well the power setting idea does not seem to be working - I'm just losing too much altitude. Maybe the concept works with 150HP, but it seems I'll have to indeed give it full power going up, pulling back on top, and feeding it in the last 1/4 of the loop.
 
volvo164 said:
Bart - which competition are you planning to attend?
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I just checked the IAC contest calendar and didn't see a contest listed yet for NJ. There have been two in NJ in the past, not sure what the plan is for this year. If I can get the time off I can probably make it up to Vermont in July but I have to try to make it to Oshkosh too so not sure which is more important to try for just yet.

We can start a new thread for flying the Primary sequence in a 7ECA without inverted fuel/oil. It would probably help a lot to have someone to work through it with. Interested?
 
Great video! Your 7KCAB is even the same colors as mine! What throttle/RPM's are you pulling on the down lines? I am constantly pulling throttle to keep from red lining the tach.
 
I generally have two throttle settings, WFO and OFF. When it sounds good don't look and pull back some. Aggressive throttle on the downline to get target airspeed is the best way to conserve altitude. The faster you accelerate, the faster you get to airspeed the less altitude you loose and the better your RPMs stay within range. In IAC your lines need two things, a) to be recognizable and b) symmetric before and after the roll. Get to the line and establish it, pound the throttle, and pull / push aggressively at the target airspeed. Being "gentile" won't do and actually will lead to the overspeed troubles as you gently try to glide in to the speed.

Look at the videos and see how aggressive my pushes are from level to a downline. Probably around -1/2G to -1G. That does a few things including telling the judges you mean business besides getting you quickly to the line. Being smooth burns altitude and doesn't present well because you lines won't be well defined. Some guys call it "popping" the stick to "set" the line. Level, push, line, bang, airspeed and pull pop it to stop.

There are few things more fun than to whip the Extras flying the lowly Citabria. The 7KCAB is fully capable of pretty much anything thrown at it in Sportsman. I tried really hard to fly intermediate with it but some of the maneuvers it just wouldn't consistently do well. For grins, try doing some inverted turns and rollers. It actually does quite well with those.
 
Feman43 said:
I generally have two throttle settings, WFO and OFF. When it sounds good don't look and pull back some. Aggressive throttle on the downline to get target airspeed is the best way to conserve altitude. The faster you accelerate, the faster you get to airspeed the less altitude you loose and the better your RPMs stay within range. In IAC your lines need two things, a) to be recognizable and b) symmetric before and after the roll. Get to the line and establish it, pound the throttle, and pull / push aggressively at the target airspeed. Being "gentile" won't do and actually will lead to the overspeed troubles as you gently try to glide in to the speed.

Look at the videos and see how aggressive my pushes are from level to a downline. Probably around -1/2G to -1G. That does a few things including telling the judges you mean business besides getting you quickly to the line. Being smooth burns altitude and doesn't present well because you lines won't be well defined. Some guys call it "popping" the stick to "set" the line. Level, push, line, bang, airspeed and pull pop it to stop.
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Agree 100% with all of this, especially the part about pulling firmly. Gentle is not gentle. Load up to 4G and stop the speed buildup.

The only point I would disagree on slightly is the pop. Not so much to disagree as to add some nuance. I think contest pilots overestimate the degree to which abrupt control inputs appeal to judges. Decisive centering of the stick is a good way to set lines. However, overly violent pull initiations at high speed are a bad habit, and IMO unnecessary. A smooth and firm pull up is better technique than jerking the stick, and more aesthetically pleasing to observers.

I think some of that jerky style came from the days when Pitts ruled the skies. That plane is so small that it is hard to see what it is doing, so the focus is on the lines drawn. Citabrias and Decathlons are bigger, and everyone knows the roll rate is much slower, so expectations are different.

The most awesome Sportsman sequence I ever saw was Jason Newburg in a T-28. Thing of beauty. Smooth, graceful lines, and finished the sequence in the box without an altitude break. He did not win, but he should have.
 
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