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Roll question-aerobatic type

trib

Well Known Member
I'm a newbie to aerobatics and have a basic question. All I do is rolls currently, but plan on getting some training for the basic positive-g stuff. When performing aileron rolls, I've had several different answers concerning rudder usage and am trying to determine what the effects are to determine the best approach for me. Van's epistle has you place both feet on the floor:rolleyes:. I've just been performing rolls with a neutral rudder. The aerobatic book I have which was recommended here (Szurovy/Goulian) recommends rudder in the roll direction as you enter the roll and then neutral throughout. Other's have recommended applying rudder in the roll direction throughout the roll. Note I am only talking about an aileron roll and not a coordinated roll where top rudder is applied in conjuction with elevator.

Can anyone fill me in on the benefits of applying rudder vs. Van's feet-on-the-floor method? Does it speed up the roll? Just looking to understand how it affects the maneuver and would appreciate any info.:eek:

thanks
 
Give this a try

Tim

Good question. My technique (not necessarily the book correct answer) is an attempt to keep the aircraft in trim, i.e. no yawing moment, while performing an aileron roll. Flown aerobatics in several different types of aircraft and almost all of them will yaw somewhat when the ailerons are aggressively displaced.

Give this a try next time you fly, trim the aircraft for level flight hand off. Hold the stick perfectly still/neutral and apply a little rudder. The aircraft should roll somewhat in the direction of the rudder. Each aircraft will roll a little different. Swept wing aircraft for example will have a tendency to roll a lot with an aggressive amount of rudder input.

I'm not an aero engineer, just my humble experience from actual flights.

Hope this helps.
 
Rolls

Hi Tim: Here are thoughts from the perspective of a Pitts owner who has done some competition and also been lucky enuf to fly RV-8's from the back seat. Three types of roll exist, usually called aileron (or slow roll), barrel, and snap roll. What you're doing with the Van's technique is really close to a barrel roll like the one Bob Hoover does in the Shrike while pouring water into a pitcher on the glare shield. It's a coordinated maneuver maintaining at least some positive G all the way around. The tendency of RV's to remain coordinated with little rudder input makes this roll easy to do. The aileron or slow roll like the ones done in competition are a lot more difficult and uncomfortable. You try to fly the airplane along a straight line flight path while rolling (at a constant rate). In reality the pilot goes closer to the zero lift attitude than that required for a straight flight path for part of the roll and some altitude is usually lost. The G load goes all the way from +1 to -1 and in directions other than straight up and down. Any liquid you pour will definitely go all over the plane! The are challenging and fun to do well. A snap roll is totally different and Van doesn't think the RV's are well suited to doing these. Read Mueller's book and Neil William's as well for really good descriptions of these. Dividing rolls into three types is a little arbitrary but useful. There are really a lot of variations you could explore later! Have fun and consider some basic instruction so you can recognize and recover from all types of spins before getting too far along. Best to you - Bill.
 
Tim,

I think Van recommended no rudder for the sake of simplicity, considering the minimal adverse yaw associated with RV's. Adverse yaw still exists, though. Unless you are doing a level competition roll (negative G), here's how you can break down non-negative G rolls (barrel rolls not included):

1) Rolling the airplane in a fashion most comfortable to you and a passenger. This means maintaining exactly 1G throughout the roll, as well as perfect coordination. This roll WILL require constant slight rudder pressure to counter adverse yaw which will exist as long as you are deflecting the ailerons with the plane at positive AOA. If you leave your feet on the floor, you will notice a very slight "slide" in your seat, just as if you rolled into a turn with no rudder. My RV-3 rolled slightly faster with coordinated rudder throughout.

2) Rolling the airplane under positive G, but minimizing your altitude deviation from start to finish. This involves some non-coordinated top rudder during the knife-edge portions to replace lost wing lift with some fuselage lift, and also relaxing some back pressure (but still remaining above zero G) passing through inverted. This combination of rudder and elevator can reduce the pitch up needed before rolling, without causing an excessive dive and airspeed build-up exiting.

3) Ballistic rolls - this is basically pitching the airplane up a bit, unloading the elevator to the zero lift position (zero G) and rolling the airplane while maintaining zero wing lift. This roll requires no rudder, since there is no adverse yaw at zero AOA. You might throw a tiny bit of oil out the breather doing this one. Secure loose cockpit items too.

Aerobatic and spin training...PLEASE do it - you'll have fun!
 
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Tim...

First of all, as with posters above, one has to be concerned you are "self teaching" aerobatics :confused: If that is the case, please don't - like self taught formation, if you are lucky you'll frighten yourself / bend the aeroplane, if not... worse :(

Specifically
Can anyone fill me in on the benefits of applying rudder vs. Van's feet-on-the-floor method? Does it speed up the roll?
you only add pro-roll rudder to speed the roll rate up, but in the 1st half this causes the nose to drop, which means you either need to raise the nose lots before entry, or you lose lots of height :mad:

Compared to other types, the RV roll rate is good, so I would suggest the Vans technique i.e. leave the rudders alone. In our RV-8 it takes only a touch of pro-roll rudder to "topple" the Dynon i.e. >150deg/s - which is a very respectable roll rate.

HTH
Andy
 
Tim,

I agree with all the others, please get some training, you will enjoy it and you'll also enjoy the aerobatics much more afterwards!

For the type of roll that many people fly - pull the nose up a few degrees, slap the stick across, wait for the World to come right ways up again and centre the stick (and pull out of the dive) - there is no benefit in using rudder.

For the competition roll that Bill described above, especially if flown at slow airspeed or not very fast roll rate (more of a training figure), then rudder (and elevator) is essential to make the roll work properly. To start you would use rudder opposite the roll to keep the nose up and reduce some of the back stick, as the roll progresses the inputs change/reverse. Get a good book (Alan Cassidy, Eric Muller, etc) to read a better descrition than I can write - you need to find out about Phorley's circles. One problem is that a reasonable amount of aileron is required, but often only small rudder or elevator movements, so it is difficult to make the right control input without someone showing you what to do first. When it works properly, and you come out on heading and without changing height, it can be very satisfying.

Snap rolls are something else altogether and use full rudder, some stick and probably no aileron to initiate. But once again, go read a good book to understand what is happening.

Pete
 
AILERON ROLLS

For probably well over fifty years a slow roll and an aileron roll were two very different types of roll. Then a few years ago the International Aerobatic Club meddled with this and started trying to call the two maneuvers the same.
A slow roll is a roll on any axis where the longitudinal axis of the airplane remains on the desired line, whether that line is horizontal, vertical or 45 degrees. The rudder and elevator inputs are constantly changeing to accomplish this on the horizontal or 45. On the vertical rudder and elevator inputs are basically just trimming the aircraft to stay on line.

The aileron roll, before the IAC meddling, was basically just a training maneuver, not used in competetion. The aileron roll is accomplished by raising the nose far enough above the horizon so that the maneuver is completed with the nose at or near the horizon. In the RV this could be as little as 20 degrees. In a Stearman with its ponderous rate of roll the initial pitch should be much steeper and the maneuver will likely finish with the nowe well below the horizon. With the RV starting out with a pitch angle around 30 degrees would be good. Use of rudder really doesn't matter, but I prefer to start people out with just a touch of rudder in the direction of the roll. When I was teaching in the Pitts, the aileron roll was the first meneuver I would teach. I would try to get the trainee to do the first roll without my demonstrating or helping.

The problem with self taught aerobatics, especially in any clean airplane like the RV, is loss of control. Typically the roll is stopped in the inverted position. the pilot has a nice leisurely look around, and then panics and pulls the nose thru. This can easily result in speed and/or g load beyond limitations. One RV6 pilot admitted to 300 m/h and coming VERY close to the ground.

Barrel rolls come in two basic varietys, the military style and the civilian style. In the military the nose travels 90 degrees off the original heading and returns to the original heading. The civilian is 45 degrees off heading at the inverted point and then returns to the original heading. A barrel roll is very easy to do but VERY difficult to do perfectly.

The rolls that Hoover did in the Shrike were a cross between an aileron roll and barrel roll. No inverted fuel or oil in the Shrike and Hoover kept just enough positve G to keep the engines and fuel system happy. Maybe only a fraction of positive G at times.

PLEASE GO GET SOME PROFESSIONAL TRAINING
 
For probably well over fifty years a slow roll and an aileron roll were two very different types of roll. Then a few years ago the International Aerobatic Club meddled with this and started trying to call the two maneuvers the same.

Nope...stop your IAC hatin' :D Checkout the IAC rule book. "Slow roll" is still the official nomenclature, though informally, competitors just say "roll" unless it's a snap roll. IAC competition only recognizes three types of rolls - slow roll, snap roll, and super slow roll (gliders only). BTW, "slow rolls" should always be done as fast as possible in competition. :) Now that we resolved this important matter, continue discussing side slip vs. forward slip...:)
 
Secure stuff first!

I was out flying with a friend I had my OPEN tool bag in the back, not secured in any fashion.

Sure enough, he asked me I would roll the RV. No problem, one aileron roll coming up. Nose up, neutralize the stick, feed in the aileron and over she goes.

Well, there was one problem...

While we were exactly upside down we hit an air pocket. Over the hush of the ANR headsets we could both hear the tools clinking around and immediately turned and looked at each other.

After finishing the roll and looking in the back, expecting the worse, we found not a thing was out of place and it looked as if the bag never moved. Boy, that was lucky!

BTW, the most G's I've ever pulled doing a simple aileron roll is 1.3 and I think that was mostly a result of an over aggressive pull up at the start.

As a reminder, the RV-9 is not an aerobatic aircraft. It is not intended to be rolled, looped, spun or a bunch of other things that would make a "normal" person green. Do not try this in your -9. Blah, blah, blah...
 
BOOKS

The basic aerobatic book that I like the best is Fly For Fun by Bill Thomas. Do a google search, it appears this book is still available direct from Bill.
 
Smooth rolls.

I don't get motion sick, but I get queasy pulling a lot of G's, so I learned to do the "smooth" roll in my 7.

Pick an airspeed (I often do these while in cruise). :)

Nose up about 5 degrees, start the roll and keep pulling up "slightly". Neutralize the elevator and give a "tiny" bit of push while inverted. Lose the push as we come around. If I did it right, I'll be at the starting altitude and direction, with no (or hardly any) pull up.

Done right, it's so smooth it feels like the world turned while we sat still.

It's harder to describe than it is to do.

YMMV.

Oh yea, I'm usually too busy grinning to even remember if I pushed the rudder. :)
 
After I bought my -6 I flew around with a spare litre of oil standing in the back of the baggage compartment, because I didn't have a good handle on the consumption yet and wanted to be ready with a spare litre in case I needed it. I just put it back there and intended to secure it "later" but forgot about it.

Of course, the first day I went out and did some ballistic rolls (nose up, neutral elevator, aileron only, exit nose slightly down), I *completely* forgot about it. But, when I got back on the ground and happened to glance into the baggage compartment while getting out, I noticed the litre was still in the same place. And still standing up. These really are amazing airplanes.

I think while doing ballistic rolls (as long as you don't hit an air pocket like Bill did) the baggage compartment floor is always on the "outside" of the CG as you roll, so things that are low and close to the floor always experience positive G. Still, you shouldn't rely on that for security. Time for a baggage net. :)
 
Nose up about 5 degrees, start the roll and keep pulling up "slightly". Neutralize the elevator and give a "tiny" bit of push while inverted. Lose the push as we come around. If I did it right, I'll be at the starting altitude and direction, with no (or hardly any) pull up.
Do you have inverted systems? If not, do you get much/any oil coming out of your breather tube? I've been avoiding any zero- or negative-G points in my rolls because I've been told i'll be cleaning the belly afterwards... But I don't really know how much negative it takes.
 
negative g's without an air/oil separator

I was taught to do aileron rolls by setting speed at about 150mph, pull up to about 15* pitch, neutralize the elevator, and then slap the aileron over.

The RV-7 will describe an arc as it rolls:mad: similar to the frown on this guys face, and finish the roll at about a 15* pitch down angle.

Last week I slapped the ailerons over before neutralizing my plane (still had a little up elevator in). Well, when a plane is upside-down, up elevator will send you down! I felt the negative g's as I rolled through inverted and recovered with about 30* pitch down angle.

The Dynon G meter showed -0.3 g's.

Back on the ground, I spent the next hour washing the belly of my RV.:eek:

Time to work on better technique or getting an air/oil separator.
 
Oops

I've done about a couple of dozen aileron rolls as I described in the first post. I had first been up with two other RV pilots who demonstrated an aileron roll and felt comfortable doing one myself after this. I had also studied the technique described in the aerobatic book, and from Van's epistle, and understood what not to do, potential problems and how to recover (i.e. no pulling the stick while inverted for that bottom split-s at high speed :eek:). I'll admit to an error on my third flight including rolls. I had just finished a test sequence and was brimming with the joy of flying and decided to do a couple rolls before heading in. Szurovy warned of not releasing aileron pressure during the roll as this will lead to the world stopping and in my case with a carburated engine, some disconcerting sputtering and engine possibly stopping. Well, you guessed it. I don't recall releasing aileron pressure, but I do recall the roll severely slowing down, my timer falling out of it's holder on the panel (upside down at this point), and the engine sputtering. I held the stick against the aileron stop and eventually was right side up again. Indicated -.6 g's on the dynon. I start with 30 degrees up angle before neutralizing the elevator.

When I returned, I found I had lost 1/2 quart of oil. It was amazing that this 1/2 qt of oil could cover the entire bottom of the fuselage, including the rudder!!

Szurovy notes in his book that this normally only happens once:rolleyes:. Guess I'm good to go now. Lesson learned.

Other than that, I've never seen any oil on the belly-zero, none, and I followed earlier advice and just skipped a separator. In other words, don't fret about the oil on the belly if you keep the aileron hard over during the roll.
 
I'm a newbie to aerobatics and have a basic question. All I do is rolls currently, but plan on getting some training for the basic positive-g stuff. When performing aileron rolls, I've had several different answers concerning rudder usage and am trying to determine what the effects are to determine the best approach for me. Van's epistle has you place both feet on the floor:rolleyes:. I've just been performing rolls with a neutral rudder. The aerobatic book I have which was recommended here (Szurovy/Goulian) recommends rudder in the roll direction as you enter the roll and then neutral throughout. Other's have recommended applying rudder in the roll direction throughout the roll. Note I am only talking about an aileron roll and not a coordinated roll where top rudder is applied in conjuction with elevator.

Can anyone fill me in on the benefits of applying rudder vs. Van's feet-on-the-floor method? Does it speed up the roll? Just looking to understand how it affects the maneuver and would appreciate any info.:eek:

thanks

Trib, depress the rudder just slightly in the direction of the roll as you apply aileron. It will overcome any yaw induced by the prop gyro effect and any adverse yaw as a result of aileron movement. Once you begin the roll, just relax the pressure on your foot. Do not counter the pressure with your other foot when you rollout. As technique, raise the nose of the aircraft ~5 degrees before you begin the roll. Make sure you are not loaded up when you apply rudder/aileron. Also, make sure you have plenty of altitude for any acro; you can never have too much. Manage your energy and plan your maneuvers WRT altitude/entry-exit parameters/geo-refs before you step to the aircraft. I also recommend you talk yourself through the maneuvers on the ground and in the air. All these techniques worked well for me when I flew jets in the AF. I found they work well in civil aviation, as well.

John
 
Make sure you are not loaded up when you apply rudder/aileron.
John

I was also taught this. Make sure you're stabilized before applying Aileron. I like 140 kts, pitch up, stabilize....apply aileron and then rudder when in the inverted portion of the roll to speed things up reduce loss of pitch. Applying earlier will result in a greater nose drop. A Right roll is easier on your Pax in a side by side I have been "told". I had a Cessna Aerobat that required more flying through every portion. These RV's make it easy really.
 
Scott,
I am not going to tell you how to fly but In gentleman acrobatics I have never slapped an aileron to do any roll. It is just not needed.
If as you say you pull up to +15 degrees you should be able to roll your 7 with about 2-3 inches of aileron travel on the stick and wind up with the nose back in level flight. I can roll my 7 at 120 mph for a nice slow Bob Hoover roll or 170 mph when doing 8 point rolls
Mark Fullerton is begging me to come fly competitive aerobatics but not sure if the increase maintenance cost is worth it.
I have not totally decided yet. 48 years of loving aviation as a career and hobby.
Jack
 
RV's are easy to roll, and dangerous for solo beginners because when you end up with the nose pointed down you will be through VNE in a flash and the g limit is pilot controlled.
The feet on the floor (beginner's roll) is easy and results in a pretty good roll, starting with the nose well above the horizon and ending up level of a bit nose down. When you are comfortable with these you might try "stepping on the sky" as you approach he vertical portions of the roll. Sometimes called applying top rudder. When this becomes routine try applying a bit of forward stick as you approach the inverted portion.

The goal is to roll smoothly with minimum altitude change. I am assuming a non inverted fuel and oil system. Have fun and always be at least three mistakes high.
chuck ross Vernon BC
 
YGBSM

Mark Fullerton is begging me to come fly competitive aerobatics but not sure if the increase maintenance cost is worth it.
I have not totally decided yet. 48 years of loving aviation as a career and hobby.
Jack

What is this increased maintenance cost? I should add that to the list of excuses people have given me for not flying aerobatics. The most common one is "I'm too old for that". (Haven't heard that from anyone older than me yet!)

I have been flying aerobatics in my RV-8 for eleven years now. I do the same yearly condition inspection as those who do not fly aerobatics. I do keep an eye out for maintenance issues between inspections; shouldn't we all do that?

PS: Mark Fullerton is one of the best aerobatic coaches around. You should definitely take the plunge!
 
Hartzell requires annual inspections on a blended airfoil prop I am told
Most Acro planes do not reach TBO
Can't speak for others but my RV has 2100+ hours on the engine and still going strong after 8 years of air show aerobatics and 7 years of aerobatic competition.:)
 
Yes you and the rest are still running your composite Hartzell props that were made for acrobatics when The team was together.



Let's not get this wrong I love acrobatics. Just don't have a real need to prove much to myself. Kinda of like old Bob Hoover. Just love to do my own energy management. Like I said no firm choice yet on competitions.
Jack
 
just fun

Participating in an aerobatic contest was a bucket list item several years ago. Now it's just fun and a chance to associate with my good buddies like Ron and Jerry, as well as the best pilots in the world. You don't need to compete to join the group.:)
Bill McLean
RV-4 slider
lower AL
 
Hartzell requires annual inspections on a blended airfoil prop I am told
Most Acro planes do not reach TBO

If you're already doing acro, why do you feel competition acro would accelerate your maintenance schedule? One of the widespread misconceptions about the sport is that you must beat the airplane significantly harder compared to recreational acro. Not the case at the Primary/Sportsman level. Unfortunately the term "competition" conjures up images of Sean Tucker's flying, which is the polar opposite of competition style acro.

Regarding not reaching TBO, there are two main reasons acro planes don't reach TBO...many tend to spend a lot of time sitting, and many have high compression pistons which means the top end won't last as long. I have known many folks with standard compression motors turning over 3,000 RPM on each flight go well over 1,500 hrs when flown regularly. I'm approaching 1,700 hrs on my motor. Still going strong. Flying a little Sportsman level acro in your RV really isn't gonna change your cost of ownership.

I've never considered the sport to be an opportunity to "prove" anything to myself or others, or to "compete" with anyone. It's just a way to have fun, challenge yourself, enjoy the learning process, and make friends with great folks.
 
If you're already doing acro, why do you feel competition acro would accelerate your maintenance schedule? One of the widespread misconceptions about the sport is that you must beat the airplane significantly harder compared to recreational acro. Not the case at the Primary/Sportsman level. Unfortunately the term "competition" conjures up images of Sean Tucker's flying, which is the polar opposite of competition style acro.

Talking with a friend on the way home from an IAC chapter practice day last weekend, we both agreed that IAC acro as coached that day was quite a bit more violent than recreational acro or even mock ACM. I think the concern is valid and wouldn't dismiss it. Before dismissing it as poor coaching, I'd add that the coach is on the U.S. Unlimited team so it's not a newbie coaching a newbie.

And there are, in fact, maintenance items. Engine mounts/isolators, stretched horizontal attach bolts, and more are documented and findable via this forums search mechanism. Not common or even serious/expensive, but they are there.
 
Coach

Talking with a friend on the way home from an IAC chapter practice day last weekend, we both agreed that IAC acro as coached that day was quite a bit more violent than recreational acro or even mock ACM. I think the concern is valid and wouldn't dismiss it. Before dismissing it as poor coaching, I'd add that the coach is on the U.S. Unlimited team so it's not a newbie coaching a newbie.

And there are, in fact, maintenance items. Engine mounts/isolators, stretched horizontal attach bolts, and more are documented and findable via this forums search mechanism. Not common or even serious/expensive, but they are there.
A coach from the Unlimited team MAY BE and in this case probably is a very poor choice for a Sportsman coach.
 
A coach from the Unlimited team MAY BE and in this case probably is a very poor choice for a Sportsman coach.

For sure, but that's not the point - the point is that people with RVs and new to IAC (but not aerobatics) are being coached to fly their plane...well, not all that differently from how Mr. Tucker flies his airshow. Maybe this was an isolated incident, but it's not the first time I've seen it happen either.
 
The Point

For sure, but that's not the point - the point is that people with RVs and new to IAC (but not aerobatics) are being coached to fly their plane...well, not all that differently from how Mr. Tucker flies his airshow. Maybe this was an isolated incident, but it's not the first time I've seen it happen either.
Agreed. prospective Sportsman Pilots need to seek out someone like Giles Henderson, the master of the clip wing Cub. If you have an opportunity to look at Sportsman results all the way back to the mid 70's you can see how many Pitts pilots were beaten by Giles.
Beating up the airplanes evolved from the high performance monoplanes, especially the Sukhoi, in turn the sequences in Advanced and Unlimited gradually got much tougher. Just to further clarify the Sukhoi Vne is approximately 270 statute and the airplane is very happy at 11 G.
There is absolutely no reason to exceed 4 G's in a Sportsman sequence in any RV. An above average pilot can probably make it look good at 3.5.
 
For sure, but that's not the point - the point is that people with RVs and new to IAC (but not aerobatics) are being coached to fly their plane...well, not all that differently from how Mr. Tucker flies his airshow. Maybe this was an isolated incident, but it's not the first time I've seen it happen either.

I don't understand the comparison to Tucker's flying. He sees 280mph speeds, +9/-7G, lots of snaps and high speed gyroscopic/shoulder roll maneuvers that twist the **** out of everything on the airplane. Sean has his airplane rebuilt after every airshow season for a reason. I've never seen an RV subjected to anything like this type of flying.

I'm not new to the sport, judging, or coaching and I can tell you that everyone has a personal style, including experienced coaches. I said beating up the airplane significantly more than recreational acro is not required and that's true. Lots of folks mess around with loops and rolls in the 3.5-4G range. It takes about 4.5G to make round looping segments. That's not much more stress on the airplane. There's no need to pull more than that doing basic Sportsman level acro in an RV.

I cannot help how others choose to coach, but folks need to realize that there is room for personal style in this sport and the goal is not to make every pilot some sort of violent robotic carbon copy of some other pilot's perceived ideal flying style. I've seen many successful flying styles in my years participating in and judging Regional contests. Pilots need to choose the flying style that works for them and that they are comfortable with and understand that thrashing the controls and pulling 6Gs is not required for an RV to post very good scores at a contest.
 
And now, side-slipping back over toward the centerline.....

The OP's question was rudder input for a roll. Good question, which generated good answers of interest to a major part of the audience. Very, very few of us will ever enter an IAC competition, no matter how generous the encouragement. However, a big segment of the fleet will do some low stress rolling. Rolls also tend to be self-taught. When done wrong they can kill, as apparently happened with at least one popular VAF contributor in recent times. So let's talk about them.

BTW, the zombie question (reviving a seven year old thread) was how to record roll rate on a G3. Anybody know?
 
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