how to fly the perfect aileron roll?

[kjlpdx]

some of my first flying experiences were front seat of a UP-7. it has a roll rate of like 12 secs. I remember clearly stomping on the rudder at knife edge trying to keep the nose up and full forward stick when inverted. it took both hands on the stick. we called it "stirring the pot" based on the path of the stick during a roll. we would lose 1000' in that underpowered plane. anyway, I am aware of the stick/rudder movements necessary. pointing at a mtn can help as a reference point. guess I need more practice. my engine is normally aspirated, so it quits at zero Gs.

[jrs14855]

The only TOTALLY CORRECT information posted so far is by Sandifer.
A few comments:
Most Pitts S1S's have 1 1/2 degrees of wing incidence and freise ailerons. The Pitts does quite well with these handicaps because of the small size of the airplane.
In the Pitts, even with the freise ailerons, if airspeed is in the 130 or higher range, one can just aggressively put the stick against the stop and do a horizontal roll, using no other control inputs. In competition this will get you a score of 7.0 to 9.5 depending on the judge and how far you are from the judge.
The Decathalon DOES NOT have a symmetrical airfoil. Except for the new "special edition" Decathalon they have freise ailerons.
IAC is responsible for competition aerobatics in the US. (Division of FAI, the international governing body). Several years ago they changed the terminology for rolls. What used to be a slow roll is now an aileron roll. This left no place for description of a true aileron roll, which is strictly a training maneuver. A true aileron roll(old terminology) is done by pulling the nose up, at least 15/20 degrees above the horizon, and rolling the airplane without inducing negative G. A touch of COORDINATED RUDDER can be used but is not absolutely necessary, especially in the Pitts, Extra, etc.
Nearly all of the Aerobatic Books except the very recent ones will be out of date on this terminology.
I think the change of terminology was a huge mistake.

[flightlogic]

The competition video clip is sure fun to watch. Thanks !!!!

[wirejock]

Tex Johnson poured iced tea while rolling. He also rolled a 707 and got in some trouble.
A 1G roll could probably be done safely with proper training but exceed the g-load and it might not turn out so well.
http://youtu.be/pMWxuKcD6vE

[Sid Lambert]

Just so we are clear. And this stands for all aircraft, pilots and never expires...

There are 4 types of rolls.

Snap - Performed with a swift pull if the stick and a swift kick of rudder.

Barrel - Coordinated roll with a 90 degree direction change at the top of the maneuver.

Aileron - Any positive G roll that is not a barrel or snap.

Slow - A coordinated roll with no change in altitude or heading. Requires 1 negative G and 1 positive.

Agree? Good.

[scard]

Most "Other" RV pilots have no idea the difference in roll rate and roll forces that the -9 presents. In airshows, I often use my legs as roll force assist. I think I've flown them all except the 12, it is a huge understatement to say that the -9 is comparatively heavy in roll. Much more like a 172. Pitch is the same as the others. Non-harmonious by design.

[BruceEicher]

I remember Bob Hoover pouring ice tea...I rode back seat with a formation team practice. If I closed my eyes I would not have known we were doing barrel rolls, smooth and one G all the way around.

[quote=wirejock;875851]Tex Johnson poured iced tea while rolling. He also rolled a 707 and got in some trouble.

[Aerosporty]

Not unloading the elevator during the roll is the most common mistake. Just think, when knife edge, you are trimmed for 1100 pounds of lift...laterally! Same holds true the rest of the way around...2200 pounds, lift plus aircraft weight must be compensated for while inverted. Forward of neutral is required. One good cheat is to preload some nose down trim before you start, then you can relax all the way around.

[Lindamon]

Just to add to the excellent post from Mr Sandifer, once you get the basic control inputs down, the best way to fine tune it for yourself is to use an outside reference. If you pick a part of the sky directly in front of the plane (it helps a lot if there are scattered clouds and you can use one), then basically you pick that point, and do whatever it takes on the controls to rotate what you see in front of you perfectly around that point. Yes, it's a little different in a side by side aircraft, since the true longitudinal axis will be through the center of the aircraft and not directly in front of you, but the difference is small enough not to matter a lot, especially when first learning.

Rudder and elevator inputs will be constantly changing. On the final 90 degrees, it's particularly critical to get this right, as the aircraft can sideslip ("dish"), and that is where many pilots will get dinged for points.

A great way to practice the necessary coordination of aileron and rudder during a roll (as a matter of fact I think this exercise should be a required part of a private pilot check ride) is to do what we call "Dutch rolls" (not the same thing as flying a Baron in turbulence) where you roll back and forth around a point directly in front of the aircraft, the nose never swaying to one side or the other. Start out with slower rolls and shallow banks, eventually getting up to full control deflection rolls of 80-90 degrees to both sides. Do not hesitate at any point during this exercise, when reaching the end of the first roll, start immediately into the next. It will really help you time the control inputs with each other, keep your turns coordinated, and this will carry over into all your flying.

The majority of students I had could not do this consistently even at slow roll speeds and fairly shallow banks. Some started out fine, but then soon got out of synch. Everyone who flies should have this "rudder awareness" ability, it can keep you from real trouble, helping you always fly coordinated. And for tailwheel pilots, develop better all around rudder awareness.

[rocketbob]

Originally Posted by Sid Lambert

Just so we are clear. And this stands for all aircraft, pilots and never expires...

There are 4 types of rolls.

Snap - Performed with a swift pull if the stick and a swift kick of rudder.

Barrel - Coordinated roll with a 90 degree direction change at the top of the maneuver.

Aileron - Any positive G roll that is not a barrel or snap.

Slow - A coordinated roll with no change in altitude or heading. Requires 1 negative G and 1 positive.

Agree? Good.

One more, ballistic roll. A ballistic roll is at zero G, where neither wing is generating lift. Simply put the drag of the ailerons causes the roll. The neat thing is watch the ball, feet off the floor there will be no adverse yaw, ball stays centered.

Highly recommended read: http://www.amazon.com/Better-Aerobat.../dp/0954481402