Robinson R44
Senis Semper Fidelis
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Seems this will help to increase sales of R44's, and give PPL(H) pilots a bad press!
DON'T DO IT! will be a bad end to your exciting day
Vfr
DON'T DO IT! will be a bad end to your exciting day
Vfr
Why do people keep repeating the myth that a barrel roll is a 1 g manoeuvre? Think; how do you depart straight and level flight to commence the initial climb and, then, how do you pull out of the final dive?
I agree it is not (or does not need to be) a high g manouevre, but it does require more than one to be pulled.
I agree it is not (or does not need to be) a high g manouevre, but it does require more than one to be pulled.
Join Date: Nov 2003
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Well, there is a margin, but not much. Not much at all...
Since it is a teetering rotorhead, it will need positive G during the whole manouvre, so one (not me!) could pull 0.5g over the top so not to loose too much height. The problem with this is that the responsiveness in the helicopter deteriorates, since it need the helicopters weight to pull on the rotordisc to respond. Less weight, less response - 0g no response, at least to my knowledge. There's been a 206 doing a barrel-roll due to stupid parachutists, having the same rotor construction principle and limitation.
The dynamics of aerobatic flight is very interesting and a good discussion would definately bring up a few learning-points on the design of a teetering rotorhead and other designs. And an understanding of why the POH says no to such things. Sometimes it's a design limitation other times a rule-limitation.
Saying that a barrel-roll is a 1g manouvre, shows a lack of understanding of the manouvre. First you have the pull-up, the more you pull it into the vertical, the more g you can pull over the top and keeping it positive. The interesting part is that if you pull it up too much, there's no energy or speed left for you to work with over the top. If you on the other hand don't pull it up far enough, you will probably see the ASI-needle pass the redline twice, and having to pull lots and lots of g's at the bottom.
From a teetering rotorhead point of view, I'd guess a split-S with a low speed entry would be better, but then, if you survive the first part, the obvious risk of overspeed is another thing to contemplate.
This is all in theory. Myself after competing on international level aerobatics in planks, I've never rolled a Cessna or Piper. I know they can do it, but they aren't built or certified to do it, so I don't. Horses for courses.
Bottom line is that if you have the experience and skill to perform it flawlessly, you also have the experience to never attempt it. If you don't have the experience to make it, it WILL be the last experience. And insurance premiums rises for everybody else.
Now get me that BO-105!
/2beers
Since it is a teetering rotorhead, it will need positive G during the whole manouvre, so one (not me!) could pull 0.5g over the top so not to loose too much height. The problem with this is that the responsiveness in the helicopter deteriorates, since it need the helicopters weight to pull on the rotordisc to respond. Less weight, less response - 0g no response, at least to my knowledge. There's been a 206 doing a barrel-roll due to stupid parachutists, having the same rotor construction principle and limitation.
The dynamics of aerobatic flight is very interesting and a good discussion would definately bring up a few learning-points on the design of a teetering rotorhead and other designs. And an understanding of why the POH says no to such things. Sometimes it's a design limitation other times a rule-limitation.
Saying that a barrel-roll is a 1g manouvre, shows a lack of understanding of the manouvre. First you have the pull-up, the more you pull it into the vertical, the more g you can pull over the top and keeping it positive. The interesting part is that if you pull it up too much, there's no energy or speed left for you to work with over the top. If you on the other hand don't pull it up far enough, you will probably see the ASI-needle pass the redline twice, and having to pull lots and lots of g's at the bottom.
From a teetering rotorhead point of view, I'd guess a split-S with a low speed entry would be better, but then, if you survive the first part, the obvious risk of overspeed is another thing to contemplate.
This is all in theory. Myself after competing on international level aerobatics in planks, I've never rolled a Cessna or Piper. I know they can do it, but they aren't built or certified to do it, so I don't. Horses for courses.
Bottom line is that if you have the experience and skill to perform it flawlessly, you also have the experience to never attempt it. If you don't have the experience to make it, it WILL be the last experience. And insurance premiums rises for everybody else.
Now get me that BO-105!
/2beers
stick a empty fuel drum on its side
hover taxi towards it
use the downwash to roll the barrel
then you can truthfully say you've done a barrel roll in a R44
Just don't try the aerobatic version!
hover taxi towards it
use the downwash to roll the barrel
then you can truthfully say you've done a barrel roll in a R44
Just don't try the aerobatic version!
Really? silly me. I shall have to berate my old ab-initio FW instructor (A2 QFI) for incorrect gen. Even Neil Williams seems to have got it wrong too, then!
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Neil Williams: Seldom wrong...
An easy way to look at the barrel roll:
If you take a flat gift-wrap string and make a loop with it (looks lika loop) and then pull the ends apart until the string is straight, there will be a 360deg twist on it (roll). Everything in between is a barrel roll.
Too easy!
If you now take the ends and tie a knot instead, it's a snap-roll or lomcevak, depending on the knot-tieing skills.
As a final show: Take a pair of scissors and cut the string (and maybe your fingers) in multiple small pieces and suddenly you have a R44 doing a barrel-roll
/2beers
If you take a flat gift-wrap string and make a loop with it (looks lika loop) and then pull the ends apart until the string is straight, there will be a 360deg twist on it (roll). Everything in between is a barrel roll.
Too easy!
If you now take the ends and tie a knot instead, it's a snap-roll or lomcevak, depending on the knot-tieing skills.
As a final show: Take a pair of scissors and cut the string (and maybe your fingers) in multiple small pieces and suddenly you have a R44 doing a barrel-roll
/2beers
Famous last words:
I wonder if ..... ?
Watch this!!!
I'll show you somthing.
Do you think that thing could do ......?
To find out, you could buy a shiny new R44 and install radio controll equipment and then we could all watch from the ground if that would work out. You could even program all the control inputs. PM me, when you are ready. I want to see the crash, too.
I wonder if ..... ?
Watch this!!!
I'll show you somthing.
Do you think that thing could do ......?
To find out, you could buy a shiny new R44 and install radio controll equipment and then we could all watch from the ground if that would work out. You could even program all the control inputs. PM me, when you are ready. I want to see the crash, too.
Join Date: Feb 2004
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In theory sounds fantastic,yet then I woke up 
.
Leave the throwing around to the proper bits of kit .
areobatics for the plank pilots normal vfr civil choppers leave well alone.
sets a not particular good note for a ppl,new shiny chopper and the wrong attitude.........look what i can doooooooooooo?
Another point what operations manual civil choppers do allow you to do areobatics any takers,but I bet there are not many if any?
.Leave the throwing around to the proper bits of kit .
areobatics for the plank pilots normal vfr civil choppers leave well alone.
sets a not particular good note for a ppl,new shiny chopper and the wrong attitude.........look what i can doooooooooooo?
Another point what operations manual civil choppers do allow you to do areobatics any takers,but I bet there are not many if any?
Scalextric for Men
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Maybe some kind person with a massive computer and CGI software might do this. Then we could all see it and stay alive. Gravity is okay it's the sudden stop.
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thanks for the input, to cut a long story short, an aerodynamics arguement between colleagues led to debate on the theoretical possibility. Have since also heard rumors that it has been done in an r22? Am wishing i had of chosen another name than doucheman after having the dictionary meaning explained, but been a work nickname for too long. Thanks again
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Don't know about an R44, but I know of a Bell 407 that did a loop and roll at an air show in South Africa.
See http://hagar.up.ac.za/christo/Bell407Loop.wmv
Far as I know, the aircraft has been grounded ever since.
See http://hagar.up.ac.za/christo/Bell407Loop.wmv
Far as I know, the aircraft has been grounded ever since.
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407 loop
and this was debated at great length in an earlier thread... see The Great Loop Debate
recommended reading for doucheman
recommended reading for doucheman
Passion Flying Hobby Science Sponsor Work
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Barrel loop
1. I have seen quite some years ago a 206 do it, so yes, it is possible. But NO you should not do this (I'll try to find out if the pilot is old and bold....)
2. Same old story as before about my R44 simulator : it really starts working well, but it takes quite some time to learn to fly with it . This looks more difficult than the real thing, you only have visual clues. I also approach it off-line, that is create sec by sec control sequences that I playback, but that takes time...
Up to now I stick with hover, landing, take-off, autorots etc and validiate standard enveloppes. Of course loops etc are tempting, and this is btw of course the first things my kids want to do with it, but so far margins seem incredibly thin and they seem to crash...
Computer used : standard (uptodate) PC.
Delta3
2. Same old story as before about my R44 simulator : it really starts working well, but it takes quite some time to learn to fly with it . This looks more difficult than the real thing, you only have visual clues. I also approach it off-line, that is create sec by sec control sequences that I playback, but that takes time...
Up to now I stick with hover, landing, take-off, autorots etc and validiate standard enveloppes. Of course loops etc are tempting, and this is btw of course the first things my kids want to do with it, but so far margins seem incredibly thin and they seem to crash...
Computer used : standard (uptodate) PC.
Delta3
I remember reading somewhere on Rotorheads about an R22 rolling, airborne, not on the ground. (When? What thread? Dunno. Too many late nights ppruning, like right now...) If I remember correctly, it sounded like a low-G tail rotor-coupled roll. 
Somehow the pilot survived, and Frank R. couldn't wait to talk to the lucky SOB. 
Somehow the pilot survived, and Frank R. couldn't wait to talk to the lucky SOB.
The R in 44
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Yes, this thread has been done before. But apart from the inadvisability of such shenanagins, why do people say such things cannot be done? Of course any helicopter can be looped and/or rolled, no matter how many (or few) blades it has. The various laws of nature are not suspended simply because we do not like the airframe or it's attached rotor system.
Well Rotordog....old trusty partner....shuck about 80 pounds and rent a 22 and put on a demo for us. Same construction as the 44 , more plentiful and a lot cheaper, thus easier to replace should theory and reality take divergent paths (along with some rather sensitive bits). We could watch a video tape of yer demo by remote computer....no need for solid overhead cover that way thus not as difficult logistically.
If you were to invite the IMAX crew done...we could slow the film speed way down....watch the blades as they twist, scoop, tuck, dive, warp, feather and all that....and see just how the dynamics work out. Think of the fame that would await you here.....with accolades from all around.
If you were to invite the IMAX crew done...we could slow the film speed way down....watch the blades as they twist, scoop, tuck, dive, warp, feather and all that....and see just how the dynamics work out. Think of the fame that would await you here.....with accolades from all around.
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Since everybody knows that helicopters actually can't fly, the big thing is to get them off the ground. Once that has been dealt with, it shouldn't take more skill to actually roll it, should it?
For people lacking that skill, a good dynamic rollover with lots of bouncing around should count as a roll but then the guy or girl inside would need a low level endorsement/waiver first
For people lacking that skill, a good dynamic rollover with lots of bouncing around should count as a roll but then the guy or girl inside would need a low level endorsement/waiver first