Sunday morning loops and rolls

Hi Guys,

Hope you enjoy, you'll need to watch on a device that supports adobe flash, otherwise video quality is crappy thanks to Google who now own YouTube.

I am at the end of my Phase 1 and am slowly working through the manouvers that I want to include on my CofA.

If you watch closely, at the end of the first loop I fly though my own prop wash.

I pulled 4G on my first loop, the loop itself was nice, but the Gs felt horrible.

In each successive loop after that I tried to pull less G, and eventually got it down to 3.7G. I was aiming for 3.5 but did not quite get there.

I am also trying to work out a good entry speed, I was using 150 knots, but as I was pulling less G the stall warning was just starting to going off in my ears as I went inverted over the top when I relaxing my pull

I am still learing, so any suggestions on entry speeds etc. are welcome

http://www.youtube.com/watch?v=OU4uvSZPliA&feature=youtube_gdata_player

Cheers
Eddie

eddieseve said:

I am still learing, so any suggestions on entry speeds etc. are welcome



Cheers
Eddie

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Vne for loop entry if you want them truly round.

Hi Smokey,

So I gather that the dive before the loop is then the normal thing to do?

I am not sure I want to dive to Vne, at least not just yet, so for weekend fun type areos, what are typical entry speeds that most people are using?

RV-4 constant speed prop,,, engine set at 22” and 2400 rpm,,, straight and level cruse, about 170 MPH,,, I do whatever I want and never touch the power. My loops are intentionally not round, there egg shaped, as tall as I can get them without stalling at the top, I can do a loop like this with only 2.5 Gs and never exceed 3 Gs. This is what I consider “gentlemen” aerobatics, intended for my enjoyment only, not any judges on the ground. I also don’t dive to enter a loop, it’s not necessary.

loops

I do round loops all the time with entry speeds as low as 125 knots. I do formation loops with a Pitts at 130 knots that are round. There is no requirement to dive to Vne. The RV airplanes perform very nicely at a wide range of speeds. Van used to loop his RV -4 at 100kts. I like the feel of the controls at lower speeds especially in roll axis.

Chris M

Hi Chris,

How hard do you initially pull for loop entry at 130 knots?

Like Russ I am interested in gentlemans aeros, but I am not sure if I am pulling too hard, I am not to keen to stall inverted, but I guess I should experience that as part of Phase 1 so that I have at least covered unusual attitudes and recovery.

Guess I should grab an instructor and get a few more pointers doing aeros in the RV, all my training has been in a Citabria, thus my tendancy to dive slightly before entering the loop.

eddieseve said:

Hi Smokey,

So I gather that the dive before the loop is then the normal thing to do?

I am not sure I want to dive to Vne, at least not just yet, so for weekend fun type areos, what are typical entry speeds that most people are using?

Click to expand...

Eddie,

You can enter a loop at cruise speed and only pull 2.5 to 3 G's as long as you accept an "L" shaped loop. Just be careful about pulling G's at slow speed at the top of the loop (float it). You can stall while inverted if you get to aggressive.

eddieseve said:

Hi Chris,

How hard do you initially pull for loop entry at 130 knots?

Like Russ I am interested in gentlemans aeros, but I am not sure if I am pulling too hard, I am not to keen to stall inverted, but I guess I should experience that as part of Phase 1 so that I have at least covered unusual attitudes and recovery.

Guess I should grab an instructor and get a few more pointers doing aeros in the RV, all my training has been in a Citabria, thus my tendancy to dive slightly before entering the loop.

Click to expand...

2 Gs on the way up, diminishing the higher you get tell it?s almost 0 G across the top. I have stalled at the top before, releasing back pressure corrects the stall and if it rolls a little I have just continued the roll to recover upright with the nose below the horizon, I have also continued the loop, I have only had this a few times and the airplane gives you a nice bump to tell you it stalled.

I have done some loops at slow speeds but don?t know what I pulled.

ronschreck said:

Eddie,

You can enter a loop at cruise speed and only pull 2.5 to 3 G's as long as you accept an "L" shaped loop. Just be careful about pulling G's at slow speed at the top of the loop (float it). You can stall while inverted if you get to aggressive.

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"float it" that's the perfect description for what i'm doing at the top of my loops.

I'm just a junior flopper, but one thing I noticed that might help in the loop is to take a quick peek out the sides when you're going inverted at that point where all you see is sky, rather than to continue looking up and forward while you're waiting to pick up the horizon. Equal amount of horizon on each wing. I generally use 150-160mph for entry, initially pull maybe a little harder for the up line than you appear to be doing, regularly make eggs, and average 3g or less. But what does a flopper know?

loops

A nice loop can be flown at 2.5 G. The pull is changing during the course of the loop. As speed decays on the upside the back pressure is decreased until you are inverted. If you pull too hard over the top you will feel the stall buffet, just ease off the pressure a little. As you come over the top the pull is increasing as speed increases. You would think a loop was an easy figure but a good one takes alot of practice. There are contest guys on this forum who can disect the manuever better than I.

disclaimer... the above is not meant as flight instruction.

ps. Doing loops in a glider is a good way to learn them. My first loop was in an Aeronca Champ.
Chris M

Thanks guys,

I really appreciate the feedback, I'll go out and do more practise next weekend to see if I can improve.

As far as the looking left and right goes, yes I forgot to do that and will incorporate into the next session

Cheers

For most of you guys trying to do actual round loops, don't worry about it. I've never seen anyone do a good round loop who hasn't received a good bit of ground critiquing by another knowledgeable acro pilot. Even among competition pilots who receive a good bit of ground critiquing, a truly round loop is one of the most difficult figures to fly perfectly, partly because it must be wind-corrected. It's almost impossible to self-critique a round loop until you learn what it's supposed to look and feel like from inside. And it's almost impossible to learn this without help from the ground. Such is the case for any truly precise aerobatic figure. So unless you have a good ground critiquer, don't put too much effort into trying to make it perfectly round, because it probably won't be, and it really doesn't matter. Just do what feels good. So with that being said, you really don't need to worry about G pulls and entry speeds too much...use whatever works, and whatever you're comfortable with. Even round loops can be done across a range (but not necessarily a wide range) of speeds. A lot of it depends on the airplane and engine/prop combo, and how much you want to load the airplane. If you're doing fun loops, you could possibly do those anywhere from under 100 mph to Vne.

And don't worry about stalling inverted. Stalling inverted is no different from stalling upright - just unload and continue around or roll upright. I've seen some folks mention that stalling at the top of a loop puts you at risk of entering an inverted spin. It doesn't. If you monkey-foot the rudder for some reason at the top of a loop, you could possibly spin, but it'll be an upright spin because it's a positive G figure. I've never seen anyone do a negative G stall (required for an inverted spin) during a positive G loop. If you're doing outside loops, that's different. Aerobatics and spin training goes without saying.

What he said...

sandifer said:

For most of you guys trying to do actual round loops, don't worry about it. I've never seen anyone do a good round loop who hasn't received a good bit of ground critiquing by another knowledgeable acro pilot.

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I thought I was doing some pretty good figures until Eric Sandifer coached me from the ground. His critiques really helped. This is one guy who knows what he is talking about!

ronschreck said:

I thought I was doing some pretty good figures until Eric Sandifer coached me from the ground. His critiques really helped. This is one guy who knows what he is talking about!

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Ron, but I didn't have a thing to say about your loops. They were already very nice. I assumed you Team RV guys helped each other with those.

sandifer said:

And don't worry about stalling inverted. Stalling inverted is no different from stalling upright - just unload and continue around or roll upright. I've seen some folks mention that stalling at the top of a loop puts you at risk of entering an inverted spin. It doesn't. If you monkey-foot the rudder for some reason at the top of a loop, you could possibly spin, but it'll be an upright spin because it's a positive G figure. I've never seen anyone do a negative G stall (required for an inverted spin) during a positive G loop. If you're doing outside loops, that's different. Aerobatics and spin training goes without saying.

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Eric, thanks for your comment. Very informative. I've often wondered whether stalling upside down at the top of a positive G loop could result in an inverted spin.

What about a hammerhead. Is it possible to fall into an inverted spin from the top of a hammerhead.

Captain Avgas said:

What about a hammerhead. Is it possible to fall into an inverted spin from the top of a hammerhead.

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Yep, if you push the stick way too far forward during the pivot. It's like any other aerobatic figure where you can stall/snap/spin out if you really hamfist it. A bit of forward stick is needed during the pivot to control the gyroscopic precession that attempts to pitch the nose toward the canopy, but the amount that's needed is nowhere near enough to stall the airplane. Metal props require more forward stick than wood/composite. It took about 6" of forward stick in the Pitts with my metal prop, and that dropped to about 1.5" after installing the Catto. The "hammerspin" risk is typically associated with pilots first learning to fly hammers...they just way over-do it. It's not the sort of thing you typically do more than once. But just like flying any other aerobatic figure for the first time, you don't want to have yourself as the instructor.

I had always heard folks talk about getting into an inverted spin during hammers, but had never experienced it. So one day in the Pitts I tried to do it. After initiating the pivot, I pushed the stick full forward, kept full rudder in, and waited. What resulted wasn't what I would call a normal inverted spin. Since full power was applied and the nose was pointing toward the ground, what resulted would more aptly be called a high AoA outside snap roll...that was accelerating with increasing negative G. I pulled the power and recovered. There was over -3G on the meter, and I hadn't let it go for more than a few seconds. Renowned spin instructor Rich Stowell has some good informational videos showing the "hammerspin" and he mentions that in an airplane like the Pitts, if you let this full-power "hammerspin" continue, that the negative G could increase to the point of exceeding the G-limit of the airplane if not recovered quickly. Based on the one I did, I believe that. But in any case, there's nothing you can do in most airplanes that pulling power and neutralizing all controls will not recover you from very quickly.

Good discussion

Great discussion.

Control inputs on hammers

It also might depend on the type of aircraft. I routinely had to use full forward stick and full right aileron in my S2B to keep it from going on it's back/torquing at the very top. It won't spin unless you have an angle of attack, which is usually caused from not using enough forward stick (or going past the vertical in the initial pull) and letting the plane get on it's back some as it nears the top. I had several students fall backwards into spins because of this, and once when I was a safety pilot at a competition. The plane gets about 10-15 degrees on it's back, combine that with a late kick and there you go!

N355DW said:

It also might depend on the type of aircraft. I routinely had to use full forward stick and full right aileron in my S2B to keep it from going on it's back/torquing at the very top. It won't spin unless you have an angle of attack, which is usually caused from not using enough forward stick (or going past the vertical in the initial pull) and letting the plane get on it's back some as it nears the top. I had several students fall backwards into spins because of this, and once when I was a safety pilot at a competition. The plane gets about 10-15 degrees on it's back, combine that with a late kick and there you go!

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Good points Damon. And even if you do a perfectly vertical pivot @ zero AoA w/ lots of forward stick, if you stop the pivot with the forward stick still applied, and hold the opposite rudder a little too long, around you'll go too. I love hammers...such a simple looking figure, but so many ways to screw them up. But when done perfectly, I think they're one of the prettiest figures.

N355DW said:

It also might depend on the type of aircraft. I routinely had to use full forward stick and full right aileron in my S2B to keep it from going on it's back/torquing at the very top. It won't spin unless you have an angle of attack, which is usually caused from not using enough forward stick (or going past the vertical in the initial pull) and letting the plane get on it's back some as it nears the top. I had several students fall backwards into spins because of this, and once when I was a safety pilot at a competition. The plane gets about 10-15 degrees on it's back, combine that with a late kick and there you go!

Click to expand...

Good points Damon. And even if you do a perfectly vertical pivot @ zero AoA w/ lots of forward stick, if you stop the pivot with the forward stick still applied, and hold the opposite rudder a little too long, around you'll go too. I love hammers...such a simple looking figure, but so many ways to screw them up. But when done perfectly, I think they're one of the prettiest figures.

sandifer said:

Good points Damon. And even if you do a perfectly vertical pivot @ zero AoA w/ lots of forward stick, if you stop the pivot with the forward stick still applied, and hold the opposite rudder a little too long, around you'll go too. I love hammers...such a simple looking figure, but so many ways to screw them up. But when done perfectly, I think they're one of the prettiest figures.

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Indeed. I think if you do what you described but with a bit of positive angle of attack all the way through, you could be on your way to doing a double hammerhead, although I have never pulled off a good one, even in a Model 12 Pitts, which has the power to weight ration in it's favor. The Extra 300L didn't need as much control input, but it was a very hard airplane to spin, although it did better inverted spins than upright. I never had a student do an accidental spin in that airplane.

The hammerhead is and will always be my absolute favorite maneuver. I remember when I first got my B - after learning how to land the darn thing - I was lucky to have a very experienced competition pilot teach me the basics. I remember days of going out and just doing one hammerhead after another, for as long as I could. Nothing like that feeling of weightlessness, hanging on the prop just long enough, and watching that wing slice straight down a road or section line, nailing the pivot right on the point....<sigh>.....I need to get back to work and get flying!

I like your video very much because it seems to be one of the few aerobatic videos where the camera is positioned so we can see really well what you are doing with the stick (and even get an idea if you are doing anything with the rudders), at the same time as we are seeing what the airplane is doing relative to the horizon.

N355DW said:

Indeed. I think if you do what you described but with a bit of positive angle of attack all the way through, you could be on your way to doing a double hammerhead...

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Or a knife edge spin if you hold full forward stick and left rudder. I was referring to the situation where a student applies full right rudder to stop the pivot while continuing to hold a large amount of forward stick and rudder for too long...a nice little outside snap/spin would result. But yeah, if you continue to hold the (left) rudder you pivoted with, that would put you in double hammer territory.

Sometimes I wonder why it took so long for certain airshow manuevers to be invented. I remember one of the very first vertical rolls I did - I pulled vertical, rolled left, and kept going. I centered the stick, and even moved it to the right and it kept rolling left...I just accidentally re-invented the torque roll. I realized what happened and recovered, but then wondered why it wasn't commonly seen until Charlie Hillard did it in 1972.