When you take a pretty good sport flyer and try to do some precision aerobatics and critique those maneuvers. Both planes fly like crap in the latter instance!

There MAY be a club level event in the Cedar Rapids IA area in September. My only two choices for a plane at this point is a Sig Four Star with an Enya 90 4C and a Pulse XT 40 with a YS 63. Both show quite a bit of roll coupling, need a lot of down elevator inverted and need a TON of aileron correction in a stall turn. The Four Star has a slight edge over the Pulse but the Enya just does not throttle as nice as the YS. (no surprise there!) I do have a YS 91AC I could put on the 4 Star.

I plan on attending this event if it takes place as it is a reasonable distance for me to drive. I'll continue to practice the Sportsman schedule and see if competitive pattern suites me at my "advanced" age.

Ken

Ken you are discovering what I have been trying to teach guys for years. Most of what you will accept for sport flying simply won't cut it for precision flying. Granted the airplanes you are flying have built in issues that can't be changed however a good trim will help considerably starting with CG. If they take more then just a touch of forward stick to maintain level inverted flight then you are just too nose heavy. When trimming you MUST always start with CG as it influences everything. Next move on to thrust line adjustments. Just these two things will make the sequence much easier. You are on the road to finding out why guys who want to be competitive in pattern are spending so much money on their airplanes. Pilot skill is a huge factor but will only take you so far, you need the correct tool for the job but that tool has to be adjusted correctly as well. Not saying you won't have a great time flying what you have in sportsman, just that you will enjoy it more if your airplanes are trimmed to their full potential.

Yes, speedracer is correct. And you will probably find that correcting the c/g will remove some of the roll coupling and other nasty habits. If you have a decent transmitter with some mixing capability, you can take care of most of the residual coupling issues and make a big improvement. If you don't have mixes on the transmitter, consider getting one soon. It will come in handy when you fly competitively.

G, I think you meant pitch. Roll couple is a function of wing dihedral versus wing CL location vertically on the fuse, relative to the thrust line. These are primary. There are some subtle secondary as well.

pitch couple is a function of CG, and wing and stab incidence. These are primary. There are more subtle secondary variables, but getting the primary right will get you practically all the way there.

Correct, Matt. Meant to say that roll coupling can for the most part be mixed out. A little easier than changing the wing dihedral and position.

I spent a little time with the Pulse tonight making some adjustments. I assumed I had "covered" a warp into the wing. Turns out the wing is straight to less than a 1/4 degree. I'm calling that close enough for the moment. I reshrunk the ailerons so they exactly matched the wing tips and root. They were slightly off I looked very closely at the elevators and found the wire joiner was not holding the elevator halves level. Some major twisting and hoping like heck I didn't break something had them level. It took a tad bit of heat to align the tip of the offending elevator as I did "level" that tip when I recovered the plane last winter. The CG is right on spec at 2 3/4 from the leading edge of the wing, so I can play with that a bit. I increased the aileron travel as it was kind of lazy in the roll. I think that is some of my diving issue is, I was waiting for the plane to be inverted before feeding in some down elevator. I need to work in my rudder skills! Still the CG will most likely change. The airframe is almost over powered with the YS63 on the nose. I kind of wish my YS 53 hadn't taken a crap. That was a near perfect match for the airframe.

At first I thought making adjustments to the Pulse would be an exercise in futility. "Why "waste" time on something that is far from precision"? After giving it some thought I decided it doesn't matter the airframe, it all translates to a better flying plane and what I learn here will work on a future pattern plane!!

I almost forgot. I have a Hitec A9 TX. I don't know all the capabilities but I know it has enough mixes to take care of what I need.

A new re-maiden tomorrow night

Ken

Attaboy!!

My pilot skills are weak so I need REALLY good tools! LOL

I think??? my thrust line is about right as there is little change in elevator needed for different flying speeds. I'll look a little harder at that variable.

I have a copy of Brian Hebert's Triangulation trimming. I'll refer to that. I made a bunch of basic changes so will need to do a bit of retriming for level flight first and possibly move the CG around a tad. We'll see what tomorrow night brings.

Ken

Ken, CG plays a bigger part in the elevator trim remaining constant at different air speeds then thrust line does. For the most part I only adjust thrust line to trim vertical flight. It's a long process and most things will overlap. Sometimes you end up adjusting something multiple times. At some point the adjustments get so small that you need to fly them a couple weeks before deciding it was a good or bad adjustment. There is no perfect setup, just one that has the least flaws.

Wing incidence is what will affect pitch changes at different speeds. Thrust will affect verticals.

Well.....I flew the Pulse tonight. Much different airplane than what it was two days ago. Loops track straight as long as the pilot does his job. Still some roll coupling but there is nothing I can do about that with out a new wing which I'm not doing. I wound up adding 1/2 ounce to the tail which helped the dive upon rolling inverted. I burned about a 1/2 gallon of fuel tonight I was so pleased with the performance. The re maiden saw a couple beeps of aileron trim and a couple beeps of down for level flight depending on speed. I'm flying for the most part a 2/3ish throttle. Most maneuvers are easily performed at that setting though it seems a little faster can help on some. The pilot, I won't mention his name needs a lot more practice. I'll fly the plane as is for a few more flights and then decide what I want to do. Now if I can only land the plane with out bouncing it Working on it but in the two years I've been flying this plane I think I can count on one hand the bounceless landing I've had Maybe a little more elevator travel is needed???? I'm landing at full elevator now right on the verge of a stall at a "fast walk" speed???

Ken

If the plane is almost stalled, then you have enough elevator. Just need to keep a bit more speed up so you can flare properly.

yes, yes and yes. Decide if you are able to move the CG back any farther. The benifits of that is the airplane will land even easier and you can reduce the amount of elevator travel needed. Less elevator travel can help keep your wings level on pulls. A mistake that many guys make is maintain a nose heavy condition and then try to correct by running more elevator travel. This ends up stalling the stab which is often mistaken for a tip stall. IMO if you need to hold more then 1/8 forward stick to maintain inverted flight then the CG can be moved back more.

While on the topic of landings. I see at every contest guys trying to stretch the flare in order to touch down directly in front of themselves. At the end of the day that approach gets less points. Don't focus too much on where the touch down happens. Establish a good rate of decent and keep it as constant as possible. The landing starts being judged at 2M of altitude ( supposedly) but the judges are watching your entire approach. Come straight in, keep the wings level and try to line up to runway center using rudder. Maintain your rate of decent, gradually reducing rate until contact with runway. Do not balloon up or drop onto the runway.

welcome to precision flying. Like I tell other guys, Morphious has offered you the blue pill and the red pill. From now on you will forever use what you have already learned and will be learning in the near future on every airplane you fly from here out.

Excellent advice above. To clarify one point, establish your rate of descent then use the throttle to maintain it and hold the elevator constant until the final flair. You should have enough elevator for a gentle arrival!
Good Luck!

Part of the issue with this plane is the relatively light wing loading. It is just plain hard to slow it down enough to make it stop flying without a long extended low approach. I tend to come in kind of hot anyway (learned from flying a CAP232 for a long time) so I need make an adjustment on my approaches. To compound the issue when the wing comes into ground effect the problem grows a bit. I haven't really been trying to stretch the landing, only wanting a slow enough approach to a bounceless landing. I suspect the semi symmetrical wing may also be playing a role?????

In retrospect it may be a good thing as it will force me to really pay attention to my approach and FLY the airplane all the way to the ground. I'll try a little more tail weight and see where that takes me. When I find the balance point sweet spot I'll remove the stick on weights and move the battery to suite. I already have the fuel tank setting on top of the wing near the CG. Battery and RX are on top of the tank at the moment.

Thanks to all for the suggestions. I'll give them a try.

Ken

Actually what you are telling me still suggests a forward CG. Nose heavy tends to land longer regardless of the wing loading. Two examples from opposite ends, my 40% Extra has a light wing loading while my Macchi pylon airplane at 520 sq. in of wing and 6.5 lb flying weight is what I consider relatively high wing loading. With just a slight breeze I am able to land either in 100 ft. The common thread between the two is a correctly placed CG however not so far back that stability suffers. Once I have it all sorted out my Symphony pattern airplane should only take 50 ft of runway.

I was kind of thinking that but needed somebody to hold my and and tell me it was OK. Thinking about it the YS63 is quite a bit heavier than the "spec" engine. In spite of the CG being at the midrange of the specifications I would hazard a guess that is still pretty conservative considering this is a "Sport Plane". I'll keep adding weight until I find the backside of the limit, or I'm happy with the landing/flying characteristics.

Ken

The Enya came out of the 4 Star tonight and a YS 91 AC now occupies the spot. The fuel tank was moved back as far as possible to minimize CG change due to fuel burn off. I moved the RX and battery rearward but I think the battery will need to go back forward a bit. I just need to plumb the fuel tank and set up the throttle linkage. I only have room for a 12 ounce fuel tank but that will suffice as I envision most flying will be at 1/2 to 2/3 throttle settings.

Ken