Originally Posted by Dirt Doctor

Cam, your 2nd para contradicts itself! If there is aileron differential then by definition one or both ailerons moves more one way than the other. ??

Hello Bobby,
I may have not described it well.

Both of my ailerons are set up, such that, up travel is same on both sides, and down travel is same on both sides,

but, the degree of travel is less for the aileron going down, compared to going up.

I hope I have not confused you and I further

On my current Dalton, she has over 300 flights.
I wanted to see if I could cut some weight out.
She weighs 46 pounds.
Flies straight as an arrow.

But I wanted to see If i could trim some fat.

Currently, there is a 2 ounce weight inside the stab tube, which I did within the 1st 10 flights, as I felt I noticed she was "nose" heavy.

I put that in quotes, as you will see what I mean by that.

Well, after adding that weight, she flew, what I thought, "way better".

Ok, here we are, over 300 flights, and I decide to trim some fat out, so I remove the cowl, and the baffle plates, and then look to see what I can do.

I began by reaming out a 2" hole in the firewall, and then I removed this aluminum plate, in the back of the firewall, that helps disperse the load of the compression of the mounting bolts, i removed the stainless steel mounting bolts, and I cut out the bottom of the cowl, to allow more air to exit.

I then replaced the mounting bolts with titanium 75 mm length SCHS bolts and titanium washers, front and back, the back ones have an OD of about 1", and then I used titanium lock nuts.
I reinstalled the baffle plates and then the cowl.

All in all, I cut out 10 ounces of nose weight (net).

I also did some measurements. My fuel tanks, when I top them off, 2 liters of gasoline, add 3 pounds of weight. And at the end of the flight, they are 1/3 full, so I shed 2 pounds, however, the tanks are mostly over the wing tube.

Ok, so yesterday was the flight with this "new" set up.

it was very windy and gusty yesterday. And upon take off and level flight, I did not notice that I had to make any trim adjustments.

She was flying level, as before.

There were three changes I noticed, and this is difficult to say, due to the high winds, and it was a cross wind also.

I have read Peter Goldsmith trim chart discussion, which is awesome.
So these were the findings:

1. Spin entry.... dramatically improved. This airplane has never done this before, And I attribute this to the fact that it has always been too nose heavy, and now it is just perfect! Removing the 10 ounces has made a huge difference. I wish I had known this before. This is also mentioned in the manuscript, that besides the upside down 45 degree climb test, the more subtle way of seeing the cg is by the ability to do a stall. Now, it comes to a complete stop in forward movement, and then the nose comes down. whereas before, I really had to give a lot of elevator, and even then, it would not "break" and kind of mush down. But now, this is fixed.

2. landings.... before, this airplane would come in fast and hot, now, it floats in to land! totally different in this ability. This change, I cannot explain, and would request any insight from those who now the physics, who can explain this change.

3. My knife edge mix is off. When I do point rolls, it is now pulling one way, i will not mention which way, I want to see if anyone can guess how changing the CG would affect this, when I have not changed my elevator trim.

Originally Posted by orthobird

Hello Bobby,
I may have not described it well.

Both of my ailerons are set up, such that, up travel is same on both sides, and down travel is same on both sides,

but, the degree of travel is less for the aileron going down, compared to going up.

I hope I have not confused you and I further

Ok, THAT is aileron differential! Thanks for the clarification. I liked Tom Wheeler's explanation of why your plane did what it did on the downline with no engine power!!

quick question for the gurus...

In the intermediate sequence, there is a down loop, with a half roll in the bottom, then push to exit upright.

Ok, here is my question...

when performing the half roll in the bottom,

let's say I want to do a slow roll, but still maintain the radius of the loop.

Judging question is

??

where you start the roll, let's say 8 o'clock (going counter-clockwise)

will there be points taken off if the roll is done by let's say 6 or 5 o'clock?

meaning, it is not centered?

Originally Posted by orthobird

quick question for the gurus...

In the intermediate sequence, there is a down loop, with a half roll in the bottom, then push to exit upright.

Ok, here is my question...

when performing the half roll in the bottom,

let's say I want to do a slow roll, but still maintain the radius of the loop.

Judging question is

??

where you start the roll, let's say 8 o'clock (going counter-clockwise)

will there be points taken off if the roll is done by let's say 6 or 5 o'clock?

meaning, it is not centered?

Yes it is .5 point for the every 5 degrees the half roll is off center.

Originally Posted by The_Wreck

Yes it is .5 point for the every 5 degrees the half roll is off center.

WOW!! i will be darned!
SO the roll has to end on the same point as to where it started, on the upside of the radius?

Very interesting, and now, even more difficult to do!

thank you for telling me this.

Originally Posted by orthobird

WOW!! i will be darned!
SO the roll has to end on the same point as to where it started, on the upside of the radius?

Very interesting, and now, even more difficult to do!

thank you for telling me this.

Down loop rolls are very difficult to maintain the radius and roll rate. Requires a lot to rudder.

People get really up tight about this down loop with the half roll. Typically when I'm judging it, I am deducting more points off for the quality of the loop (flat spots, corkscrew off line etc) than the half roll part of the loop. Most people would probably score better on that maneuver by concentrating on keeping the loop round with no flat spots, and just do a quick half roll at the bottom.
For those that do it as a blended (rudder and elevator with aileron) it might help to realize the plane should be knife edge at the very bottom of the loop.

Thank you both so much, now I know what I have to do, and what to look for to know whether or not I can do it.

I will set up a flight mode, that I will activate before starting the down loop, that will increase rudder throw, maintain same elevator throw, and decrease aileron throw.

I will first practice doing this, way way high!

Wish me luck!

Originally Posted by orthobird

Thank you both so much, now I know what I have to do, and what to look for to know whether or not I can do it.

I will set up a flight mode, that I will activate before starting the down loop, that will increase rudder throw, maintain same elevator throw, and decrease aileron throw.

I will first practice doing this, way way high!

Wish me luck!

I have found my roller rate works well for down loop rolls. It is basically setup just as you describe.

I never cease to be confused why IMAC pilots and many judges seem so stuck on doing slow roll rate figures. Certainly most judges seems to carry that bias, despite there being no criteria for rate other than it be constant.

I recall when I attended an IAC judging school and the subject of roll rate came up. The consensus of the IAC pilots was that there is no such thing as rolling too fast. IAC judges seem to understand this and have no bias towards slow roll rates.

As Bill noted, there is no reason to do this figure with a long, slow half roll. Do a quick 1/2-roll centered on the bottom of a nice round loop and you will see higher scores. Those tick marks in the Aresti diagram do not denote where the roll must start and then stop. The only criteria is the roll element must be centered on the apex of the loop and along the radius of the loop.

Originally Posted by Judge

I never cease to be confused why IMAC seems so stuck on doing slow roll rate figures.

IMAC.... OR Pilots,.... Bill.
Pilots fly...... AMA sets the rules.I agree with you completely regarding the roll rate requirement in the criteria.
W

Originally Posted by Judge

I never cease to be confused why IMAC seems so stuck on doing slow roll rate figures. Certainly most judges seems to carry that bias, despite there being no criteria for rate other than it be constant.

Not sure what region you compete in, but in my 8 years of IMAC I have yet to hear a judge express any bias to slow rolling, in fact most advice I have heard is the faster you roll the less chance you have to screw something up.

Originally Posted by wmat7039

IMAC.... OR Pilots,.... Bill.
Pilots fly...... AMA sets the rules.I agree with you completely regarding the roll rate requirement in the criteria.
W

You know what I meant. I edited it for clarity. And you also know that AMA does not write the rules in a vacuum. IMAC proposes almost all of the rules as they currently exist, so it is incorrect to give the impression that the rules are developed by the AMA.

Originally Posted by The_Wreck

Not sure what region you compete in, but in my 8 years of IMAC I have yet to hear a judge express any bias to slow rolling, in fact most advice I have heard is the faster you roll the less chance you have to screw something up.

I flew in the SW as well as judged at the Shootout. Perhaps where you are roll rate is not biased, but out here, and in most places I have heard about, most judges and pilots seem biased toward slower roll rates.

I agree with the faster rates and generally fly like myself.