Ranking Aerobatic Aircraft

Greebo

N9017H - C172M (1976)
Joined
Feb 11, 2005
Messages
10,976
Location
Baltimore, MD
Display Name

Display name:
Retired Evil Overlord
Welcome!

Welcome to the new "Pilots of America" Forums. You've found us in our infancy right now - we're still working out the specifics of our setup and administration - but feel free to register an account, hop on in and say hello!

In the near future, we will be setting up a series of Aviation related forums for US based Pilots and anyone else with an interest in or, more likely, passion for aviation.

Right now our Administrative Council is still working out the details, and as decisions are made, the look, feel, and content of these forums are subject to potentially radical change. So please pardon our dust, put on a set of non-polarized sunglasses, put your tray up and lock it and return your seat to its upright position, and take off with Pilots of America!

Chuck "Greebo" Haeberle, PP-ASEL
 
Re: Citabrias ...

Ken Ibold said:
Late to the party (there was some kind of air show I had to go to ...)

To sum up: A Pitts is a dedicated acro machine that in its time was world class (and is still very good, even by modern standards). A Citabria is not and never was.
Ken, following up on your comment about modern standards, which aircraft is considered today's best acro machine? Also, what are the qualities that define the best aerobatic planes? I'm guessing horsepower and wing shape are two. Is more power always better, or just up to a point?
 
Re: Citabrias ...

Toby said:
which aircraft is considered today's best acro machine? Also, what are the qualities that define the best aerobatic planes? I'm guessing horsepower and wing shape are two. Is more power always better, or just up to a point?

From the looks of it, and a few world aerobatic championships, Kirby Chambliss chose the Edge 540. It has an unbeliveable roll rate (420 degrees a second). It is my favorite to watch. Here is a pic from Luke Day 2005
 
Last edited:
Re: Citabrias ...

Toby said:
Ken, following up on your comment about modern standards, which aircraft is considered today's best acro machine? Also, what are the qualities that define the best aerobatic planes? I'm guessing horsepower and wing shape are two. Is more power always better, or just up to a point?

Toby,

Not Ken but I couldn’t resist the question.

In my opinion, the best measure of aerobatic airplanes is what Alan Cassidy developed and calls an “Aerobatic Performance Index”. He discusses it in his book (page 64). It uses a “formula” place a value on an aircraft as an aerobatic performer. In summary, there are three components of this index:

Power/Weight ratio
Maximum level speed
Maximum roll rate

The calculation is:
pwi = Power (hp) / Weight (kg) / 0.36
msi = Max level speed (knots) / 165
rri = 1.6 / e(220/(roll rate exp 1.1))
API = pwi * msi * rri * 50

The roll rate is complicated but is designed to give decreasing benefit to roll rates in excess of 420 degrees / sec.

As Cassidy himself states, “[The index] has not been put to any official use in defining standards, but it has been useful in policy discussions and bar talk alike.”

I believe I have a spreadsheet at home that does the calculations and if I find it this evening I’ll edit this post and include it as an attachment. You can input the numbers for your own airplane and see how it stacks up.

As an overview, here are a few aircraft and their API’s:

Pitts S2A – mid 30’s
Extra 200 – mid 40’s
Pitts S2B - low 50’s
Giles G202 – mid 60’s
Extra 300S – mid 70’s
Sukhoi 31 – mid 80’s
Edge 540 (highest) – low 90’s

The “best of the best” in these rankings are the Edge 540, the Sukoi 31, the Pitts S-1-11B (described to me by one airshow pilot as a huge engine with a balsawood airframe), and the CAP-232. Sad to say Extra 300/L is no longer considered a serious unlimited contender. I’ll have to calculate its API tonight. I’m going to guess somewhere in the mid 60’s.

Chip
 
Re: Citabrias ...

Chip,

Excellent! I look forward to the spreadsheet.

No wonder I liked the Sukhoi. I have to find out which model it was. Somehow I'm thinking 29, but I don't know where I got that number. Let us know how the Extra stacks up.

At what API is an airplane able to do all the maneuvers, I wonder? I mean all the basic maneuvers including the vertical ones.

Also, I wonder which aircraft has the highest + and - G loading?

Sorry, this thread is creeping away from the initial subject. Should I move it?
 
Seemingly lost in this discussion of the BEST is the fact that an entire generation of pilots learned aerobatics in aircraft that had flat bottomed airfoils, no inverted anything, relatively low power to weight ratios, and high drag, in fact aircraft that had performance remarkably similar to a current, garden variety, 7GCAA Citabria, not even a Decathalon. Given that they learned aerobatics in such pedestrian aircraft it is nothing short of amazing that the WWII fighter pilots had so much success in combat??????????

We seem to be obsessed with having the best when in fact as a trainer an aircraft with less performance, lower power, higher drag, lower roll rate will force the student to develop better planning, better stick and rudder skills. Bill Kershner spent years teaching aero in Cessna 150/152 Aerobats because they were easy for the student to fly, because they were cheap.......

Duane Cole put on a flawless exhibition everytime he strapped on his clipped wing, 150 HP/inverted fuel/oil, Taylorcraft. In fact I've seen the audience turn away from a high-energy snarling Pitts performance in boredom BUT stand transfixed in awe watching Duane FLY, no tumbling all flying, a graceful performance in the T-craft, and end it with the same performance deadstick. No one ever looked away when Bob Hoover FLEW his very graceful demonstration in anything, especially the Aero Commander.

BEST...............for what? High-energy, high G aero, audience appreciation, training, all VERY different missions, all have very different requirements. Instead of obsessing on the best aircraft we should concentrate on developing the highest level of skills suitable to our mount of choice.

There was a time when airshows were flown in clipped wing Cubs, Great Lakes, Stearmans (both stock and 450 HP), Citabrias.........before Decathlons, a good argument can be made that those shows were more interesting to watch, and that it required a different skill set, much closer attention to available energy, to do aero in a long winged, high drag, low thrust, flat bottomed, aircraft.

Tom-
 
A Cessna AEROBAT is the best.

Skyport said:
Seemingly lost in this discussion of the BEST is the fact that an entire generation of pilots learned aerobatics in aircraft that had flat bottomed airfoils, no inverted anything, relatively low power to weight ratios, and high drag, in fact aircraft that had performance remarkably similar to a current, garden variety, 7GCAA Citabria, not even a Decathalon. Given that they learned aerobatics in such pedestrian aircraft it is nothing short of amazing that the WWII fighter pilots had so much success in combat??????????

We seem to be obsessed with having the best when in fact as a trainer an aircraft with less performance, lower power, higher drag, lower roll rate will force the student to develop better planning, better stick and rudder skills. Bill Kershner spent years teaching aero in Cessna 150/152 Aerobats because they were easy for the student to fly, because they were cheap.......

Duane Cole put on a flawless exhibition everytime he strapped on his clipped wing, 150 HP/inverted fuel/oil, Taylorcraft. In fact I've seen the audience turn away from a high-energy snarling Pitts performance in boredom BUT stand transfixed in awe watching Duane FLY, no tumbling all flying, a graceful performance in the T-craft, and end it with the same performance deadstick. No one ever looked away when Bob Hoover FLEW his very graceful demonstration in anything, especially the Aero Commander.

BEST...............for what? High-energy, high G aero, audience appreciation, training, all VERY different missions, all have very different requirements. Instead of obsessing on the best aircraft we should concentrate on developing the highest level of skills suitable to our mount of choice.

There was a time when airshows were flown in clipped wing Cubs, Great Lakes, Stearmans (both stock and 450 HP), Citabrias.........before Decathlons, a good argument can be made that those shows were more interesting to watch, and that it required a different skill set, much closer attention to available energy, to do aero in a long winged, high drag, low thrust, flat bottomed, aircraft.

Tom-
 
That's odd.

How did the posts in this thread get attached to one of my old old posts?
 
Skyport said:
BEST...............for what? High-energy, high G aero, audience appreciation, training, all VERY different missions, all have very different requirements. Instead of obsessing on the best aircraft we should concentrate on developing the highest level of skills suitable to our mount of choice.
Tom-

Tom, you are correct and your is point well taken. I fell into the "best means highest performance" trap, and that isn't the case. And I couldn't agree more with your statement about "developing the highest level of skills suitable to our mount of choice."

The flip side of this is how often I hear that I should learn aerobatics in a lower performance aircraft before moving to something like an Extra. I don't agree with that at all. Learning to fly aerobatics in a Citabria does not prepare me for flying aerobatics in an Extra, just like learning to fly aerobatics in an Extra does not prepare me for flying aerobatics in a Citabria. "You're only current in what you're current in." It's all about "skills suitable to our mount of choice."

Thanks for the reset.

Chip

(By the way, my current favorite airshow performance is Bobby Younkin in the Super Decathlon. Absolutely unbelievable what he can do with that airplane.)
 
Greebo said:
That's odd.

How did the posts in this thread get attached to one of my old old posts?


Uh, I have no idea. I think Brian was messing with the thread tools and he must have screwed something up. :rolleyes:

Chip
 
gibbons said:
Uh, I have no idea. I think Brian was messing with the thread tools and he must have screwed something up. :rolleyes:

Chip

For the right $$$$ amount, I can be bought to back your story up
 
I think Joe needs at least 2 or 3 flight hours worth for me to buy this story.

And I need a few too.

You already know my paypal address though. :)
 
As promised, here's the spreadsheet. You can plug the numbers into the spreadsheet yourself (green cells) to see where your mount falls on the scale.

It's an attempt to quantify a subjective argument about performance, but I think it has value. It may be difficult to see the difference between a Pitts S2B and a Pitts S2C, but the magnitude of difference in performance between a Super Decathlon and a Sukhoi 26 is apparent.

Yours for discussion.

Chip
 
Last edited:
Harold Johnson was famous for low altitude loops, rolls, and spins..................in a Ford Tri-motor. I strongly suspect he would be capable of quickly checking himself out in an Extra and doing a similar performance. I doubt that there are many (any) Extra pilots who could quickly do the opposite.

How many have ever seen an aero performace in a stock Stearman, if you've ever flown one you will surely appreciate the skill required. For many years after WWII that, and the 450 HP version, was the aero mount of choice, in fact the oft maligned 7GCAA/GCBC has a better HP to weight ratio and is in fact a much better aero mount than a stock Stearman, and quite comparable to a 450 Stearman.

Once again, learn to fly what you have, learn to make one plane sing and dance and you will be able to quickly makes others walk and talk.

Tom-
 
gibbons said:
The flip side of this is how often I hear that I should learn aerobatics in a lower performance aircraft before moving to something like an Extra. I don't agree with that at all.

Once again, we will have to agree to disagree. Where is Marty Mayes, btw? I miss him.

gibbons said:
(By the way, my current favorite airshow performance is Bobby Younkin in the Super Decathlon. Absolutely unbelievable what he can do with that airplane.)

You should be flying with him in the Decathlon when he does maneuvers. It's like no other flying I've ever done. It was smooth as silk, and flawless flying; like a dream.
 
Last edited:
Skyport said:
Once again, learn to fly what you have, learn to make one plane sing and dance and you will be able to quickly makes others walk and talk.
Tom-


Tom, it's nice to have you posting here. You add years of experience and a wealth of knowledge. :)
 
Last edited:
Skyport said:
Harold Johnson was famous for low altitude loops, rolls, and spins..................in a Ford Tri-motor. I strongly suspect he would be capable of quickly checking himself out in an Extra and doing a similar performance. I doubt that there are many (any) Extra pilots who could quickly do the opposite.

Tom-

I have no doubt that he could, but could he make the Extra or an Edge 540 fly to it's fullest extent in short order? Low altitude loops, rolls, and spins aren't even close. How long do you think it would take Wagstaff to figure out how to roll anything, including a Tri-motor at any altitude?

But we're talking hypothetically here. My point is simply that you learn to fly any aircraft well by flying THAT aircraft, and not by flying any other.

Chip
 
gibbons said:
As promised, here's the spreadsheet. You can plug the numbers into the spreadsheet yourself (green cells) to see where your mount falls on the scale.

It's an attempt to quantify a subjective argument about performance, but I think it has value. It may be difficult to see the difference between a Pitts S2B and a Pitts S2C, but the magnitude of difference in performance between a Super Decathlon and a Sukhoi 26 is apparent.

Yours for discussion.

Chip
Thanks for the spreadsheet, Chip. I'm out of town right now, but will work with it when I get home.

I don't see why you say it's subjective. If you're calculating weight: power and other quantifiables, the results should be pretty clearcut.
 
Hmmm would this be the ultimate Necropost??????? It being ThreadID 1 and all :D
 
Re: Welcome!

Welcome to the new "Pilots of America" Forums. You've found us in our infancy right now - we're still working out the specifics of our setup and administration - but feel free to register an account, hop on in and say hello!
It is 4 years later and you are still working on the "specifics"

;)
;)

:D:D
 
Re: Welcome!

Welcome to the new "Pilots of America" Forums. You've found us in our infancy right now - we're still working out the specifics of our setup and administration - but feel free to register an account, hop on in and say hello!

In the near future, we will be setting up a series of Aviation related forums for US based Pilots and anyone else with an interest in or, more likely, passion for aviation.

Right now our Administrative Council is still working out the details, and as decisions are made, the look, feel, and content of these forums are subject to potentially radical change. So please pardon our dust, put on a set of non-polarized sunglasses, put your tray up and lock it and return your seat to its upright position, and take off with Pilots of America!

Chuck "Greebo" Haeberle, PP-ASEL

In the beginning.... there was a blue board
 
Last edited:
Re: Citabrias ...

Toby,

Not Ken but I couldn’t resist the question.

In my opinion, the best measure of aerobatic airplanes is what Alan Cassidy developed and calls an “Aerobatic Performance Index”. He discusses it in his book (page 64). It uses a “formula” place a value on an aircraft as an aerobatic performer. In summary, there are three components of this index:

Power/Weight ratio
Maximum level speed
Maximum roll rate

The calculation is:
pwi = Power (hp) / Weight (kg) / 0.36
msi = Max level speed (knots) / 165
rri = 1.6 / e(220/(roll rate exp 1.1))
API = pwi * msi * rri * 50

The roll rate is complicated but is designed to give decreasing benefit to roll rates in excess of 420 degrees / sec.

As Cassidy himself states, “[The index] has not been put to any official use in defining standards, but it has been useful in policy discussions and bar talk alike.”

I believe I have a spreadsheet at home that does the calculations and if I find it this evening I’ll edit this post and include it as an attachment. You can input the numbers for your own airplane and see how it stacks up.

As an overview, here are a few aircraft and their API’s:

Pitts S2A – mid 30’s
Extra 200 – mid 40’s
Pitts S2B - low 50’s
Giles G202 – mid 60’s
Extra 300S – mid 70’s
Sukhoi 31 – mid 80’s
Edge 540 (highest) – low 90’s

The “best of the best” in these rankings are the Edge 540, the Sukoi 31, the Pitts S-1-11B (described to me by one airshow pilot as a huge engine with a balsawood airframe), and the CAP-232. Sad to say Extra 300/L is no longer considered a serious unlimited contender. I’ll have to calculate its API tonight. I’m going to guess somewhere in the mid 60’s.

Chip

I would think the Christen Eagle would be in there between the S2A & B/C...Always a fun plane to fly....a little tricky in a strong x-wind though IMHO.
 

Attachments

  • eagle1 003.jpg
    eagle1 003.jpg
    165.2 KB · Views: 11
Last edited:
WTF? Does Chuck still exist in the ether of the pilot world?
 
Back
Top