What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Looking for advise on RV-7 Aerobatics

Rene Bubberman

Well Known Member
Hi group,

We are flying now for a month and I'm exploring the first frontiers of RV aerobatics. We have instuction from a very experienced pilot who used to fly aerobatics in an RV-6, so the basis and the safety is there. Now I'd like to read and study about this subject too, to better prepare myself for the flights. Do you have tips, threads and some recommended reading for me?
 
Fun stuff

Hi group,

We are flying now for a month and I'm exploring the first frontiers of RV aerobatics. We have instruction from a very experienced pilot who used to fly aerobatics in an RV-6, so the basis and the safety is there. Now I'd like to read and study about this subject too, to better prepare myself for the flights. Do you have tips, threads and some recommended reading for me?
Have you done and practiced on all your basic PPL maneuvers (to proficiency):

Stalls, power on, pwr off & accelerated
Steep turns
Slow flight

What you will find is the RV's do acro effortlessly and you almost need no rudder. In fact I recommend no rudder at first. Loops and Aileron rolls are easy once you learn the range of entry: speeds, power settings and G-forces.

DO YOU HAVE A G-METER? I highly recommend you get one. Not only is it a safety device if you plan on intentionally exploring the aircrafts G-limits, it will add consistency to your maneuvers. MOST all aerobatics can be done at 3G's may be 3.5G's with two people. If you are pulling more than 3G's entering a loop or recovering from one, you're doing it wrong.

Search the archives for key words like Acro or Aerobatics. There are lots of great aerobatic books out there.

As far as spins, I do them but only one or two turns. RV's, especially side-by-side RV's have some fun and fast spin characteristics once fully developed, say after 2 or more turns. I assume you have the bigger rudder? The reason for that rudder mod was improved spin recovery. If you have the small rudder I would not recommend fully developed spins with TWO PEOPLE aboard. I don't think the small rudder makes it unrecoverable, just not as positive during recovery. (Rudder Bulletin: http://www.vansaircraft.com/pdf/sb02-6-1.pdf )

One thing you must know about spins, is any aerobatic maneuver can result in a stall if botched (in any attitude or at almost any speed), which is the precursor to any spin. Of course the FIX to avoiding a stall is RELEASE THE BACK PRESSURE, regardless if you are inverted at the top of a loop and feel a buffet, release the back pressure. The good news is RV-7's are spin resistant if you are coordinate, like most planes, and they recover quickly in the early or "incipient" spin stage and with in acceptable FAA limits from a 6 turn spin. So some intentional practice stall/spin entries may be in order with early recovery. You need PRO spin control inputs to get it to start. As soon as you relax the Pro spin control input, it stops spinning immediately in the incipient stage.

I have not explored the full meal deal spins where it "winds-up", but the recovery is still the same: rudder opposite of spin, once auto-rotation stopped, stick forward to recover from stall, than recover from nose low attitude. CG should be well fwd of the aft ACRO limit of course for all aerobatics. Also the FAR's require when there is a crew of two, both need Chutes to be legal.

There was an excellent article in the RVator from some UK RV-8 pilots, who put their RV-8 through a full stall flight test and documented it in detail. They tried different spin entries, directions, power settings and different recovery techniques. As expected all stalls where recoverable and stall entries to the left are easier to enter and take more time (turns) to recover. The right spins are harder to enter and maintain even with full pro spin controls, due to the gyroscopic affect of the engine/prop and may be prop (corkscrew) slip stream changing the rudders effectiveness.
 
Last edited:
If you are pulling more than 3G's entering a loop or recovering from one, you're doing it wrong.
"Wrong" is a strong word. :D You can do loops all day long with 4 or 5 g's at entry & exit (standard don't kill yourself disclaimer applies). You certainly don't need to though. 3-3.5g's works great for just about everything.
 
Well its my opinion based on doing RV acro

"Wrong" is a strong word. :D You can do loops all day long with 4 or 5 g's at entry & exit (standard don't kill yourself disclaimer applies). You certainly don't need to though. 3-3.5g's works great for just about everything.
We can agree to disagree, but that's my opinion. It sounds like we agree, but certainly you can use 4g, 5g or 6g pull-ups but WHY? Its really poor form. I think you miss my point.

The word "wrong" may be strong, but it's the correct word in my opinion. The other way to say it, there is "NO NEED" to pull more than 3.5g's to make a good loop.

You say 5g's. OK, why not 6g's? My main concern is if you start at 5'gs you may end up at over 6'gs during the recovery, especially if you screw it up. If you're pulling more than 3 or 3.5's to initiate a loop, you're wasting energy and it's a less elegant maneuver. If you do competition acro in a RV, you do have to pull more g's to say in the acro box. However we are talking about learning and beginners acro.

The bottom line is RV's have a "fat" highly cambered wing that do not like load factors over 3g's. Pulling more than 3-3.5g just bleeds exponentially more speed off. Why does Van say "keep it light"? The lower the angle of attack the less drag, and the drag curve has a slope on it that gets steeper with AOA (load factor). Also when teaching I've made a few observations, one being new acro pilot's almost always over control & pull too many g's. Ask for 3g, they pull 4g.

The IAC (international aerobatics club) says a LOOP is started with a 3-4 g's pull-up; LINK So that is what the IAC says. Pulling more initial g's in a RV just gets you a tighter loop or a very egg shaped one. My worry is if you're going too fast over the top, the recovery at the bottom can be way too fast, closer to Vne than I personally like or is safe. Now I'm not saying to under do the pull-up or entry speed either.

I find people fly too fast and pull too hard out of fear. Pilots have worries about stalling and doing a inverted flat spin? I'm not sure you can even intentionally do an inverted flat spin in a RV? (any one done this?) Pilots fear being too slow over the top, so they start faster and pull harder (which is counter productive to maintaining speed). Yes you can get slow and stall. So what. What if you stall at the top? LET THE BACK PRESSURE GO AS USUAL. The plane will do what it always does, the nose drops and the plane flys again, finish the loop. If you really mess up, the plane will roll upright (naturally due to dihedral), and than you than recover from a nose low attitude (power idle, wings level pitch up to level).

When I teach a student a loop, I have them intentionally stall at the top of a loop, inverted of course; I tell them to pull back harder on the stick, causing a stall buffet. The plane buffets, and its no big deal. Than I have them release the back pressure. WOW, the plane flys again as smooth as can be with no snap roll or inverted spin. People also worry about "floating" over the top like that is bad, but they don't understand the forces and angle of attack. First again not to "float" is wrong. Stall speed is real low at 0-0.5 g's, which is the ideal over the top pos load factor (according to the IAC LINK). Some where in the 0-0.5g over the top is correct; anything more is wrong. :D

Entry speeds for loops can also be over done. I'm not going to recommend since Van has those, but it can be as slow as 140 mph. I like 140-160 mph, but it varies with plane, weight, density altitude, engine and prop. Like load factor of pull-up you can go faster but you can also exceed Vne if you screw up, but not so much with a loop but stuff happens. Just be careful of the Split-S, the entry should not be over 140 mph, since speed will increase through the whole maneuver which is all down hill.

I rather stall at the top of a loop, upside down (it does not matter right side up or down a stall is a stall), than getting the nose pointing straight towards the ground screaming near Vne. Pulling too many g's at the initial pull-up can result in high speed and high g recoveries. None of this has anything to do with making the perfect LOOP, just a safe one and giving more margin to the g and speed limits. None of the above is a substitute for a competent instructor and flight training.
 
Last edited:
I have not explored the full meal deal spins where it "winds-up", but the recovery is still the same: rudder opposite of spin, once auto-rotation stopped, stick forward to recover from stall, than recover from nose low attitude.

A fully developed spin will likely continue if you just apply full opposite rudder and wait for the autorotation to stop. It's an incomplete recovery technique. The opposite rudder is vital, but unless you un-stall the wing, the spin will continue. In my experience, this is true in all the RVs I've done fully developed upright spins in.

Even in the developing stage, spins stop when the wing is unstalled. But don't take my word for it. Try to exit a spin on a particular heading sometime. You'll notice that the timing of the pitch input is what allows you to stop the spin with precision.

The best emergency spin recovery technique for an RV is power off, ailerons neutral, full opposite rudder, and then un-stall the wing.

Using an incorrect and/or out-of-order recovery procedure can lead to an aggrevated spin mode or inability to stop the spin. Power or aileron inputs will be counter productive. Likewise, attempting to unstall the wing before opposite rudder has been applied will tend to accelerate the spin.

Spins are not rocket science, but I do recommend thorough ground and flight training with an experienced aerobatic instructor before trying these things in an airplane by yourself.

--Ron
 
The 3-4g pull thing is simply part of an extremely general description of maneuvers by IAC. It's not part of the definition of a spin or a competition requirement. You can make the loop as big or small as you like.

It's interesting that your students tend to pull harder than intended. I find the exact opposite -- that beginners initially pull less than desired because they're not used to significant g loading and have some natural trepidation about a) using large control deflections, and b) the possibility of "hurting" the plane.

--Ron
 
Thanks!

Thank you guys, this input is most helpful and I'll discuss it with my instructor. Do you have similar advise regarding the various types of Rolls?
 
You are right

The 3-4g pull thing is simply part of an extremely general description of maneuvers by IAC. It's not part of the definition of a spin or a competition requirement. You can make the loop as big or small as you like.

It's interesting that your students tend to pull harder than intended. I find the exact opposite -- that beginners initially pull less than desired because they're not used to significant g loading and have some natural trepidation about a) using large control deflections, and b) the possibility of "hurting" the plane. --Ron
You are absolutely right and I guess my students are retarded? :D Again high speed and higher g's are not necessary in my opinion, and RV's bleed energy off like crazy when you load the wing past approx +3.5g range. To nit pick, however there are limits to how big or small of a loop you can make, based on aircraft & energy. You can start at Vne and do a 2g pull-up and loop, but it may not be round and possibly, if over-controlled, unsafe. Staying away from the +6g and Vne or even too far past Va speed's. Its one thing to botch a maneuver, another to pull the wings off. Respect the limits. Thus the "recommend" entry speeds and load factors for beginners, middle of the envelope.

If I was Chuck Yeager or Bob Hoover (or had their skill) I'd be doing loops with the engine turned off at runway level, but sadly I'm not that skilled. :( So I keep it in the middle of the envelope and recommend pilots practice with an instructor and observe recommend entry speeds and load factors, which are NOT arbitrary or capricious. IAC recommends 3-4 g's for many good reasons. I let other folks push the limits of g's and speed. If you are flying a 12g plane with symmetric wing and an advanced acro pilot with a low level waiver, that's a different story.

Everyone has opinions about acro and some of its from fear or lack of knowledge. Pilots see the airshow pilot do these monster ++9g pull-ups and have no idea what they are looking at. That is extreme acro, not sports-mans acro, and it's totally inappropriate for a RV. There is no substitute for a good acro instructor and actual training in a good acro plane (not necessarily a RV). RV's are fine acro planes but actually too easy to fly and a little on the clean side for an acro trainer. The latter issue, cleanness is a factor in building too much speed fast in the down lines (ie nose pointed towards the ground). Talk is fine but actual practice is priceless. I think most who fly acro will find the 3-4g initial pull-up loop is just right. Good luck
 
Last edited:
Here's an AC on stalls & spins (+ old FAA video)

Advisory Circular
LINK

Here is a very old video but its a classic with stall recovery and some good through the screen views. Its old school (transferred from film) but frankly it covers everything about basic stalls and spins. (It brings back a lot of memories, but its all very relevant. There ain't nothing new under the sun. It's all the same as it always was.)

mms://media.americanflyers.net/asf/AF_FAA_Stalls.asf

It's almost 16 minutes LONG and the spin and spin recovery starts at 10 min.
 
Last edited:
Its one thing to botch a maneuver, another to pull the wings off. Respect the limits.
Indeed! Everyone should be careful with what they do & pay attention to their personal & aircraft limits.

My point wasn't that people should be doing acro at 5g's in their RVs...just that it's not impossible. I've flown acro in quite a few aircraft & there are definite differences in how you fly different planes. I really enjoy flying acro in my -6 at around the 3-3.5g range. However depending on what (video) I'm trying to get, I'll vary the g, airspeed, and (*gasp*) roundness of over the top maneuvers. ;)

Pulling your wings off would suck. Nobody do that. Ok?
 
Do you have similar advise regarding the various types of Rolls?
Inverted fuel & oil? I don't have either, so I keep ALL acro in my -6 at 0.5g or higher. I certainly wouldn't win in aerobatic competitions with that, but I like keeping the engine humming & the oil pressure up.
 
Acro

I'm having a blast flying acro in the 7a,

I probably have a gigantic 30 hours of actual acro time and am happy that i fitted the inverted fuel and oil...Yes I had a hard time not allowing my Immlemens going negative.

Not sure why (they are OK now) but I never lost oil pressure either.

Would I add inverted fuel and oil again?...Hmm not sure..I do like flying upside down just for fun so for me its sort of worth it.

Flying gentle acro (snap rolls are so slow its comical) is a sort of art form.

Of course as others have said...training is paramount and such training should include every which way to botch a manouver and recover.

First thing I had Steve Wolf show (after the Immlemen) was a totally botched immelmen..."Oh yeah, no big deal"...:)

frank
 
Just curious, I haven't done any in our 6 yet, how do these planes hammerhead?
Fine I think, but kind of tricky without the inverted systems.

The hammerhead is the only maneuver, that I, a not very good aerobatic pilot, managed to completely botch when first trying it. I was trying to keep some positive G by keeping the upline less than vertical and ended up with the engine quitting and me floating "flat-on-my-back at 10,000 feet." No harm though.
 
Yeh, floating on your back at 10K isn't a huge deal as long as you use some of those 10K to recover and get her up and running again.. :D
 
Just curious, I haven't done any in our 6 yet, how do these planes hammerhead?

I can only comment on my RV-3, but it will do a pretty nice hammerhead. I would definitely encourage some basic acro training. I would not want to subject an RV to a tailslide condition. When to initiate the hammer at the top is the most critical to not only avoiding the tailslide, but the quality of the maneuver. The right aileron and forward stick during the turnaround are pretty mechanical inputs, done in sequence that don't require much finesse. You can experiment with the amounts of aileron and elevator to keep the pivot aligned on a plane. It's near full right aileron and medium forward stick in the RV-3. Really satisfying when done right. It's a zero G maneuver on the upline, turnaround, and downline, but you can cheat the upline and downline to keep it a little positive. I haven't had problems with engine sagging or oil thrown from the breather.
 
The first couple of hammerheads that I did were quite interesting. I had not come to a complete stop going up and when I cranked it over I was instantly on my back in an inverted spin. Now things are better.
 
In the 7a

I found the hammerhead is best done with full left rudder and about half right aileron.

If you don't get the aileron in there it rolls and thats when it ends up on its back.

Frank
 
Hammerhead technique: What I was taught anyway

The first couple of hammerheads that I did were quite interesting. I had not come to a complete stop going up and when I cranked it over I was instantly on my back in an inverted spin. Now things are better.

I was was taught to start to aggressively kick in full LEFT Rudder and start to apply Right aileron as the plane's airspeed passed ~50 mph.
In our type of small lycoming powered planes the airspeed is dropping really quickly at this point so it's only a second or so between that and zero airspeed if you are going straight up. But this extra second or two of full rudder application/counter aileron application before forward airspeed is used up will pretty much almost guarantee not to end up in a tail slide or on your back from my own limited experience and really gets that turn down going again just like the they draw it up.

lucky
 
Wow.. Good read...

I need to find some time to get some aerobatic instruction before I start doing too much in the RV..
 
Yes indeed!

Training goes without saying.

I still found afterward that things are little different in the RV from the Zlin I learned in....1500 foot loops as opposed to 500ft for a start...:).

The temptation in the hammerhead when having learned on a lower performing airplane is to rotate too early....I.e the RV seems to go up forever and you chicken out and kick the rudder hoping to get it over with...:)

What happens is the tail then comes out of the prop blast and it continues to climb upwards rotated at about 30degrees...it just seems to be stuck there.

Its a little unerving but eventually it goes over.

Its a lot of fun...Actually WX has improved I'm off to do some more...:)

Frank
 
The first couple of hammerheads that I did were quite interesting. I had not come to a complete stop going up and when I cranked it over I was instantly on my back in an inverted spin. Now things are better.

Bingo....been there done that! Caused by 2 things. 1) Either not using any aileron when you still have some vertical speed - or - 2) Going past vertical on the way up, pushing-then pushing some more-then pushing some more. Just as the airspeed runs out, you are pushing, past vertical, and WHAM...you're on your back and in a spin.

These RV's will stall quite quickly the wrong way (inverted) and can catch you by surprise. A Hammerhead looks quite simple but takes a little more though/inputs than a roll or loop to execute properly. But, get it mastered and you can do them all day long. Quite fun to just go up, hammerhead, then half a roll on the way down. You can see-saw back and forth like this for a number of them and won't get too far out of the practice area that way.

My 2 cents as usual (having fallen over on my back out of a hammerhead more than once myself).

Cheers,
Stein
 
Loop Power Setting

Great info on aerobatics from everyone. I'm just starting to do aerobatics in my RV-7A and I've gotten mixed info regarding the use of power in a loop or any over the top maneuver. Do you maintain a constant power setting from start to finish or do you reduce power at the top of the loop so as not to overspeed on the back side. How have you all been controlling your throttle?
 
Great info on aerobatics from everyone. I'm just starting to do aerobatics in my RV-7A and I've gotten mixed info regarding the use of power in a loop or any over the top maneuver. Do you maintain a constant power setting from start to finish or do you reduce power at the top of the loop so as not to overspeed on the back side. How have you all been controlling your throttle?


Full power! If the loop is round you will find that your exit speed is very near to your entry speed. If you start the loop with 4 Gs you will probably need 4 Gs to finish the loop. Slack off the Gs on the last quarter and speed will run away and the loop won't be round.
 
Do you maintain a constant power setting from start to finish or do you reduce power at the top of the loop so as not to overspeed on the back side.

This is a fallacy. If you left the throttle alone and oversped while exiting at the same altitude you started from, then you just defied the laws of physics. :) You're not going to gain airspeed unless you exit significantly lower than you started, meaning you did something wrong. What Ron said. Some decent basic aerobatic training puts these types of questions to bed.
 
Last edited:
This is a fallacy. If you left the throttle alone and oversped while exiting at the same altitude you started from, then you just defied the laws of physics. :) You're not going to gain airspeed unless you exit significantly lower than you started, meaning you did something wrong. What Ron said. Some decent basic aerobatic training puts these types of questions to bed.

This (and more) is covered in "Better Aerobatics" by Alan Cassidy. He explains this quite well. I am an engineer but keeping full power to yield less airspeed on the down loop was counterintuitive to me.

I gotta get the actual training!!
 
Full power! If the loop is round you will find that your exit speed is very near to your entry speed. If you start the loop with 4 Gs you will probably need 4 Gs to finish the loop. Slack off the Gs on the last quarter and speed will run away and the loop won't be round.

Do you use full power with a fixed pitch prop?
 
Do you use full power with a fixed pitch prop?

Yes. Done properly you will likely exit a loop with almost the same speed you had a the entry. If you are concerned about an overspeed on exit you might choose to enter at a lower speed. RVs can easily loop from level flight at cruise speeds.
 
I have to speak up on this one.

I flew about 1500 hours and still fly a fixed pitch O-320 E2D .. I do use full power all the way up and most of the way over the top aiming for about 0.1 to 0.5 positive G over the top,

HOWEVER I would not even consider using full power on the way down as it would over rev way past red line RPM.

Keeping the loop round and progressively and slowly adding G on the way down will control air speed and bring you out at the same altitude as entry, but I can't imagine not pulling back on the RPM as the nose drops below the horizon on the way down and the RPM wants to push past red line. Otherwise it certainly would in my ship. (CP-328 super emeraude / CAP 10 )


I only took aero training with a CS prop Pitts, and I agree with Ron on leaving the power alone in that case.
 
I have to speak up on this one.

I flew about 1500 hours and still fly a fixed pitch O-320 E2D .. I do use full power all the way up and most of the way over the top aiming for about 0.1 to 0.5 positive G over the top,

HOWEVER I would not even consider using full power on the way down as it would over rev way past red line RPM.

Keeping the loop round and progressively and slowly adding G on the way down will control air speed and bring you out at the same altitude as entry, but I can't imagine not pulling back on the RPM as the nose drops below the horizon on the way down and the RPM wants to push past red line. Otherwise it certainly would in my ship. (CP-328 super emeraude / CAP 10 )

I only took aero training with a CS prop Pitts, and I agree with Ron on leaving the power alone in that case.

Just curious: What speed do you enter a loop and at what speed does your prop hit 2700 RPM? I'll admit to having little experience with a fixed pitch prop. Maybe Eric Sandifer will chime in here. I have heard his Pitts wind up to 3300 on many occasions! :D
 
I have to speak up on this one.

I flew about 1500 hours and still fly a fixed pitch O-320 E2D .. I do use full power all the way up and most of the way over the top aiming for about 0.1 to 0.5 positive G over the top,

HOWEVER I would not even consider using full power on the way down as it would over rev way past red line RPM.

I've never flown an airplane that will gain energy through a loop, assuming a constant power setting (full power or not) and an equal entry/exit altitude. The power setting in a Pitts during acro is usually full or idle (for spins) but I've done many loops in fixed pitch RVs from ~160mph where I added full power just before the intial pull and left it there all the way through. But I'd pull power back a bit off full after exiting level, but not on the way down. You won't exit with excess RPM/airspeed unless your exit altitude is lower than you started. How round or egg-shaped the loop is makes no difference.

But yeah there's certainly no problem turning well over 2700 RPM in Lycomings with a fixed pitch prop. Pitts drivers have been turning 3300-3400 RPMs briefly on downlines for decades.
 
I have a 3-blade Catto FP on my 8A, it gets the same engine RPM for a throttle setting/airspeed combination going up/down or sideways. Hit 2700 RPM around 150 KIAS with full throttle. If your loop is symmetrical (same G-load coming back down as going up) you should be at the same speeds, and thus the same RPM. I did initially go to idle when going down a loop (per Van's recommendations), but now don't see the need. If you mess up and start getting too much speed than do throttle back (and increase the G-load, RV's short wings have lots of drag at high loadings), but for normal maneuvers it isn't needed.

I have gained altitude doing a loop, but it was by pulling harder on the downline than the upline. Came out higher but slower than I started.
 
Back
Top