at airshows I see aileron rolls where the plane rotates perfectly about the axis of the fuselage, as opposed to a barrel-type roll. I have tried and tried to imitate this in my -6A, but my friend flying behind me says that there is always some deviation, that it isn't a perfect rotation about the fuselage axis. it seems to me the issue is lift as the plane starts rotation. I tried rolls watching and holding zero G's throughout, but I was told that didn't fix it. others have said the wing incidence is working against me, that acro planes have 0? wings. are there RV pilots out there that can tell me how to do this? it is quite deceiving from the pilot's seat what is truly occurring.
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how to fly the perfect aileron roll?
- Thread starter kjlpdx
- Start date
Sid Lambert
Well Known Member
You'd have to go negative to do one from straight and level flight. Lots of rudder and lots of push will get you close.
An aileron roll is one in which only the ailerons are used. It will always be similar to a barrel roll. What you are describing where the aircraft rotates about the roll axis is called a slow-roll. It requires coordination between the ailerons, elevator, and rudder. Somewhat more difficult.
Joness0154
Well Known Member
It'd be hard to critique without seeing any video, but it sounds like you're adding some elevator into it. A lot of people do it unconsciously.
Pitch up 20°-30°, elevator neutral, full aileron deflection to the stop in the direction of roll. You'll also need pro roll rudder to offset the adverse yaw, increasing towards the end of the roll. As the nose dips below the horizon towards the end of the roll, don't be tempted to add elevator to pull the nose up until you've rolled 360°. It's normal.
Pitch up 20°-30°, elevator neutral, full aileron deflection to the stop in the direction of roll. You'll also need pro roll rudder to offset the adverse yaw, increasing towards the end of the roll. As the nose dips below the horizon towards the end of the roll, don't be tempted to add elevator to pull the nose up until you've rolled 360°. It's normal.
Mike S
Senior Curmudgeon
This might be considered heresy to some, but it is just simply possible that the RV will not do a roll like you are used to seeing at airshows.
The RV is an example of doing many things well------"Total Performance", while many of the airshow guys are flying planes that are optimized for only one thing---aerobatics---and have decades of development behind them in that specialization.
The RV is an example of doing many things well------"Total Performance", while many of the airshow guys are flying planes that are optimized for only one thing---aerobatics---and have decades of development behind them in that specialization.
An RV surely will do a very nice straight and level roll. I seen 'em do 'em with my own eyes.
Not many RV pilots do them or can do them well, though. Some call these "slow rolls" (roll rate has nothing to do with it). In competition, we just call them aileron rolls, since there are only two types of rolls - aileron and snap. Positive G barrel rolls just don't exist. A level roll has the CG of the airplane flying a perfectly straight and level flight path through the air with no altitude deviations. Any positive G roll causes the CG flight path to corkscrew to some degree. A zero G roll causes the CG to follow a parabolic arc unless flown perfectly vertical. A perfect level roll is quite a challenge. For anyone truly interested, Alan Cassidy's book 'Better Aerobatics' has the best description of the level roll of any book available. Actually, it's the best acro book out there period. To achieve a truly good level roll requires study, some dual instruction, some ground critiquing, and of course lots of practice. A perfect level rolls puts precisely +1G to -1G on the airplane and no more. More or less than that, and you deviated. But G meters can be prone to rolling inertia errors, depending on how close to the exact roll axis they are mounted, so they may not indicate precisely +1/-1G even if the airplane was subjected to that. I won't go into detail here, but a level roll requires constantly changing rudder and elevator inputs to produce a level flight path with no altitude or heading deviations. If you don't have an inverted oil separator, you're gonna dump a little oil. If you have a carb, the engine will quit for a second. None of this is a problem as long as you monitor oil loss and are willing to clean the belly.
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humptybump
Well Known Member
There are several good descriptions in the various aerobatics books.
Here is a general description of the muscle actions ...
For aircraft without an incredible roll rate - think Super Decathlon - the sequence of a
Here is a general description of the muscle actions ...
For aircraft without an incredible roll rate - think Super Decathlon - the sequence of a
slow-roll typically starts with a small amount of up elevator followed by left aileron. As you start to roll, the pilot gradually adds right (aka top) rudder while relaxing any elevator. As the roll passes through knife edge, the pilot starts to push while taking out rudder. All this time, the ailerons are adjusted as necessary to keep the roll rate. Eventually the plane is inverted with left aileron and push on the elevator. Continuing through the roll, the pilot now starts to take out he push elevator and add in left (aka top) rudder while approaching knife edge again. Finally, the rudder is gradually relaxed and any necessary elevator is applied to keep the nose on point. When back to level, the ailerons are used to arrest the roll.
"perfection will depend on the aircraft and the pilot". Different aircraft will need adjustments to the sequence of input.
"perfection will depend on the aircraft and the pilot". Different aircraft will need adjustments to the sequence of input.
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And people wonder why we all do sloppy barrel rolls instead in our RV's....
Without getting into too much nuance, that's the basic idea, except for the taking out the rudder part after passing through knife edge. After you pass through knife edge, quite a bit of rudder is still required to hold the nose up. But there is now an additional element that prohibits the removal of this "top" rudder - and may even require additional rudder to be applied. This is adverse yaw. As you pass knife edge, the airplane starts to experience negative G. So now you must deal with negative G adverse yaw, which in airplanes without symmetrical ailerons, is even more pronounced under negative G than positive G. And add to this the fact that RVs have differential ailerons in addition to Frise ailerons (not symmetrical ailerons). That RV differential aileron that minimizes adverse yaw, allowing you to happily yank and bank with your feet flat on the floor makes adverse yaw proportionally more pronounced under negative G. Generally speaking, you don't start removing this original "top" rudder until you have passed the inverted position by about 30 degrees. This is a general rule. Different aircraft types may require the level roll inputs to be tweaked slightly, but the basics are the same.
Christopher Murphy
Well Known Member
Barrel rolls
It is rare to see a true and correct barrel roll flown too. Constantly changing roll and pitch 90 degrees off at top constantly changing pitch and roll to level
a displacement roll is not really a barrel roll.
fun thread
Chris M
It is rare to see a true and correct barrel roll flown too. Constantly changing roll and pitch 90 degrees off at top constantly changing pitch and roll to level
a displacement roll is not really a barrel roll.
fun thread
Chris M
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.
rolls
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.
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.
DANGER
The competition video clip is sure fun to watch. Thanks !!!!
The competition video clip is sure fun to watch. Thanks !!!!
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wirejock
Well Known Member
Roll a 9
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
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
Well Known Member
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.
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.
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
Well Known Member
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.
Aerosporty
Active Member
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.
Pick a point
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.
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
Well Known Member
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-Aerobatics-Alan-Charles-Cassidy/dp/0954481402
jmk
Member
barrel rolls
There are at least two different styles of barrel rolls. The IAC barrel roll, which used to be a Sportsman only maneuver, IIRC was a 45 degree change of heading, returning to the original heading at the finish. The roll and heading change were blended, with both roll and heading change constantly changing. I have always HEARD that the military style was a 90 degree change of heading but never saw anything to prove this. I always did the "military style" with heading and bank angle constantly changeing, same as IAC style except the heading change.
The IAC style was discontinued many years ago.
Tex Johnson rolled the very first 707 at a fairly low altitude over the hydroplane races near Seattle. I don't think he got in much trouble. Publicly he had to be reprimanded. Privately it probably sold a lot of airplanes which Boeing was very happy about.
Clay Lacy will be performing in the Chino Airshow Sat and Sun in the Lear 24The Late Bobby Younkin did a very impressive low level airshow in the Lear 23.
There are at least two different styles of barrel rolls. The IAC barrel roll, which used to be a Sportsman only maneuver, IIRC was a 45 degree change of heading, returning to the original heading at the finish. The roll and heading change were blended, with both roll and heading change constantly changing. I have always HEARD that the military style was a 90 degree change of heading but never saw anything to prove this. I always did the "military style" with heading and bank angle constantly changeing, same as IAC style except the heading change.
The IAC style was discontinued many years ago.
Tex Johnson rolled the very first 707 at a fairly low altitude over the hydroplane races near Seattle. I don't think he got in much trouble. Publicly he had to be reprimanded. Privately it probably sold a lot of airplanes which Boeing was very happy about.
Clay Lacy will be performing in the Chino Airshow Sat and Sun in the Lear 24The Late Bobby Younkin did a very impressive low level airshow in the Lear 23.
I used to practice "boxes" as well, slip the nose horizontally across the top of the box, stop, drop vertically down the side, stop, slip back across the bottom..... too many can make you sick, so beware. this exercise really engrains the stick and rudder movements to the view outside.
WillyEyeBall
Well Known Member
RV competition roll
Can't help it, but had to show a competition roll in an RV. It's this year's Primary sequence and the roll occurs at the end of the video clip. Let Eric be the judge, but I think the roll would score a 8.5. I do have an inverted system.
http://www.youtube.com/watch?v=fWce9wtHZVI
Bill McLean
RV-4
lower Alabama
Can't help it, but had to show a competition roll in an RV. It's this year's Primary sequence and the roll occurs at the end of the video clip. Let Eric be the judge, but I think the roll would score a 8.5. I do have an inverted system.
http://www.youtube.com/watch?v=fWce9wtHZVI
Bill McLean
RV-4
lower Alabama
stinson pilot
Active Member
Can't help it, but had to show a competition roll in an RV. It's this year's Primary sequence and the roll occurs at the end of the video clip. Let Eric be the judge, but I think the roll would score a 8.5. I do have an inverted system.
http://www.youtube.com/watch?v=fWce9wtHZVI
Bill McLean
RV-4
lower Alabama
I think Eric would say you did pretty good. Looks good to me, but I'm still a rookie too. I do love doing slow rolls. I like to do them really slow. Lots of fun.
dmaib
Well Known Member
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.
Agree!!!!!!!!
ronschreck
Well Known Member
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.
Well, NO! Look again at post #6. As far at the IAC is concerned there are only two: aileron rolls and snap rolls. You can mix it up a bit and do 4-point or 8-point aileron rolls, half rolls, etc. As well as upright and inverted snap rolls (the latter not recommended in your RV!) and vertical snaps, double snaps, half snaps, etc. But, again there are only two basic types of rolls in IAC competition. Outside of IAC call them whatever you want.
Regarding post #6: I learned long ago that one does not argue with Eric Sandifer on any subject within the realm of aerobatics. Eric is an IAC judge and one mighty fine aerobatic pilot.
You forgot Onion, Kaiser, and Dinner.
Sid Lambert
Well Known Member
Interesting subject
Never thought about all the names given to different types of rolls till I read this thread. I thought I would add a few comments.
Snap rolls used to be called flick rolls, might be a British thing. Snap rolls stall the wing with aggressive rudder and aft or forward stick. Gyroscopic forces exceed the G forces and I only do these in an approved aerobatic aircraft..
Barrel rolls are a positive G maneuver. I too have heard the 90 degree heading change at inverted version as the military barrel roll. IAC competition allowed barrel rolls in aerobatic sequences. The IAC version was a 30 degree heading change at inverted. I used one in a free style sequence one year as a cross wind maneuver to offset drift in the box. Judges were not consistent in judging it so I discontinued its use. (Early 80's). Bob Hoover poured the ice tea while doing a barrel roll and there is a video on YouTube. I talked to him about doing it and he said the hard part was pouring backhanded so the camera could see it. When giving aerobatic rides I used to balance something on my head to demonstrate coordination during a loop, wing over and a barrel roll.
Someone mentioned doing the boxes. I would use this maneuver in aerobatic training. Draw a box with the nose of the airplane while keeping the wings level. Lots of cross control and good practice. Another version is to draw figure 8's.
Aileron roll, slow roll, axial roll. In my world these always meant the same thing. Rolling the airplane on the longitudinal axis. If horizontal, it would be as was described here earlier, using all three controls to maintain a constant roll rate, constant altitude and constant path of flight. Stopping at points such as every 90 degrees would then be a four point roll, etc.
Dutch rolls or coordination exercises are a great tool to keep your feet working. Keep the nose on a point and roll back and forth, AND keep the ball centered. Stop on the points of max angle and horizontal momentarily for a little more fun. Also, put your feet on the inside two pedals (reversed rudder) and try it. Even more fun!
All this improves your coordination and skills. Great fun! Now about those 4 point hammerheads...
Never thought about all the names given to different types of rolls till I read this thread. I thought I would add a few comments.
Snap rolls used to be called flick rolls, might be a British thing. Snap rolls stall the wing with aggressive rudder and aft or forward stick. Gyroscopic forces exceed the G forces and I only do these in an approved aerobatic aircraft..
Barrel rolls are a positive G maneuver. I too have heard the 90 degree heading change at inverted version as the military barrel roll. IAC competition allowed barrel rolls in aerobatic sequences. The IAC version was a 30 degree heading change at inverted. I used one in a free style sequence one year as a cross wind maneuver to offset drift in the box. Judges were not consistent in judging it so I discontinued its use. (Early 80's). Bob Hoover poured the ice tea while doing a barrel roll and there is a video on YouTube. I talked to him about doing it and he said the hard part was pouring backhanded so the camera could see it. When giving aerobatic rides I used to balance something on my head to demonstrate coordination during a loop, wing over and a barrel roll.
Someone mentioned doing the boxes. I would use this maneuver in aerobatic training. Draw a box with the nose of the airplane while keeping the wings level. Lots of cross control and good practice. Another version is to draw figure 8's.
Aileron roll, slow roll, axial roll. In my world these always meant the same thing. Rolling the airplane on the longitudinal axis. If horizontal, it would be as was described here earlier, using all three controls to maintain a constant roll rate, constant altitude and constant path of flight. Stopping at points such as every 90 degrees would then be a four point roll, etc.
Dutch rolls or coordination exercises are a great tool to keep your feet working. Keep the nose on a point and roll back and forth, AND keep the ball centered. Stop on the points of max angle and horizontal momentarily for a little more fun. Also, put your feet on the inside two pedals (reversed rudder) and try it. Even more fun!
All this improves your coordination and skills. Great fun! Now about those 4 point hammerheads...
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