Could you do this in a 747-400?

[Hempy]

Came across this interview with Tex Johnston...707 Barrel Roll (http://www.youtube.com/watch?v=rILk6-4SMJQ). He mentions how safe it is, why don't we see this at air shows etc?

[distracted cockroach]

A well flown barrel roll is a 1 g manoeuver ie you are not pulling positive or negative g. As such their should be no stresses placed on the aircraft. An A320 for example is certified from -1g to +2.5g clean (0 to +2 with the flaps out), so a 1g barrel roll would be perfectly safe BUT I don't know any airline aircraft that are certified for aerobatic manoeuvers. As such, any attempt to roll an airliner would be viewed as a pretty reckless act by everyone from the manufacturer to the local aviation authorities so is highly unlikely to be seen at an airshow!
That said, I know of an old (WW2 vintage) ex instructor who is reputed to have rolled every aircraft he ever flew (GA only...up to Cessna 402/404 size)
Some of the aero-heads out there may be able to provide you with more info, but an aerobatic certified aircraft will certainly have to have demonstrated more than just a simple barrel roll, and will likely be rated to roughly -2g to plus 6g or better (I'm casting my mind back to C152 Aerobat numbers, but the mists of time are concealing the actual numbers from me!)
Tex Johnson is a legend, but from a time where such acts were admired rather than frowned upon. Doubt it would happen today.
Cheers
DC

[Buster Hyman]

The girls in the galley would have some issues I imagine!http://www.emotihost.com/yeah.gif

[gliderboy]

Guys
A Barrell Roll is not a 1G manouevre! It IS a positive G manoeuvre- but to get the pitch rate to describe a "barrel" around the horizon requires more than 1G initially eg up to 3G depending on aircraft.
An AILERON Roll on the other hand (if flown correctly) can be a 1G manoeuvre
Gliderboy

[J430]

Buster
Properly executed they would hardly spill a drop!...Coffee that is you filthy minded readers:}
J:E

[Pinky the pilot]

Dunno about barrel rolling a non aerobatic a/c but my late Father looped an Airspeed Oxford and lived to tell the tale!!:ok:
Knew a bloke in PNG who claimed to have looped a BN2 and tried to convince me to attempt same. My reply cannot be posted here but it was along the lines of .....Get :mad: !!!!!!!

[Buster Hyman]

Could you tell my mided was filthy from where you are???http://www.emotihost.com/wootrock.gif

[The Messiah]

Now an aileron roll is perfectly ok for any aircraft if performed correctly but Pinky a loop is an entirely different story. The bottom of a loop puts high stresses on the tailplane and will stretch the underside skin and should only be done in aerobatic type aircraft as their tailplanes are beefed up to withstand it.

There are old pilots and bold pilots but no old bold pilots.

[18-Wheeler]

As mentioned above, yes you could barrel-roll a 747 no probs.
It's a positive but low-G manoeuver and well within the factory limits of the 747.
FWIW the China Airlines 747-SP that did the high-dive years ago pulled about 5G's on the recovery, so they're plenty strong.
The avionics probably wouldn't be too happy about going inverted though.

[J430]

Ohhh Buster.........a guilty conscience:= :}

Fixed the other spelling mistake while I was at it.

J:E

[Buster Hyman]

Tis okay...I gave it a quick tidy up & she's apples now!!
http://www.emotihost.com/barmy.gif

[*Lancer*]

The China Airlines SP never flew again though...

[Animalclub]

Didn't a TAA pilot roll a TAA Viscount? Or was this "kid the new boy" talk (a long time ago)?

[JimmyReeves]

If you fly a barrel roll properly it would only be about 1 G. There are two times when you can pull more than 1 G, firstly uring the intial pitch up prior to rolling over and the other, when your attitude ends up too low upon the exit of the roll. We should ask Bob Hoover this question.

[CoolCat]

guys... A proper roll has to be only around 1G because if it were more or less than 1G this couldn't happen...

http://www.youtube.com/watch?v=Xp2Uc9XvmjY

[ScottyDoo]

This is why physics is a requirement at most airlines. Even high school physics.

You wouldn't have a bunch of pilots who think you can change direction (accelerate) without applying a 'g' loading to the aircraft.

Ok, you're right, it's a 1 'g' barrell roll..... :ugh:

[rmcdonal]

Sure it could be higher then 1g. The cup would sit in the same spot, the liquid would pour, only thing is stuff would feel a little heavier. That applies all the way down to almost 0g....after that it gets a bit weird.

[ScottyDoo]

Excellent. I look forward to the demo of a 1 'g' barrell roll at the next Avalon airshow.

As well as the rarely seen 1 'g' loop. :ok:

[Pinky the pilot]

Messiah; I am well aware of the stresses involved in aerobatics!

Hence my reply to the 'urger' concerned, which was :mad: !

[CoolCat]

I still haven't exactly understood why that guy can pour a drink upside down.
And yeh, actually I think you would be changing the value of 'G' if you're rolling because you're still changing direction and therefore accelerating.

Edit

I think the centrifugal force has a lot to do with it.

[AerocatS2A]

Two great piloting misconceptions. A barrel roll is a "one g manoeuvre" and if you fly slower than the stall speed, you will stall.

The posts above serve as a good example of why we should all go out and do an aerobatic rating and then some consolidation. Only then do you really get an understanding of what your aeroplane is (and isn't) capable of.

[A185F]

Ok I don't want to start any sh*t here but there is a common misconception that an AILERON ROLL is a Barrel Roll. It is Not.

In Hover's youtube vid there with the coffee he is basically performing an aileron roll which if performed correctly can maintain 1g. Basically just getting some speed, raising the nose to a high attitude and just rolling with ailerons with a bit of rudder . The idea of the high nose attitude is that as you roll you lose height i spose and by the time you roll round to wings level your nose should be about on the horizon (instead of pointing down and starting to spiral out of control. Theoretically there should be no elevator input once the nose is checked at it's angle.

http://www.fsstation.com/customimages/aerobatics/1.gif



A Barrel roll is basically flying (not rolling) around the inside of a barrel in a corkscrew manner. It is combining a loop and a roll and therefore there is a fair amount of pulling as well as rolling so high gs (well not high, but more than 1)

http://www.flightsimbooks.com/jfs/75-1.jpg

As I said, I don't want to start any sh*t because everyone has a different Idea about how to fly an aeroplane. However, I am just outlining that there is a difference between the 2 maneuvers and that a Barrel roll is NOT a 1g maneuver.

[Squawk7700]

Good diagrams. Makes perfect sense how the nose drops in the aileron roll in order to maintain 1G or less. If executed seems like it can be done perfectly as in the video.

Knowing little about aero's, is a Barrell roll 2 G, as in 1G normal plus 1G for the maneouvre? Last one I was in felt more than 1.

[AerocatS2A]

It depends on how tight you want to make it. I think I used to do them at about 3 g, but it's a while ago, memories fade (3g at the bottom, over the top the gs would normally be a little less than one.) You could do one at 2 g, but with a low pitch rate, you are in danger of running out of airspeed before getting around the top of the manoeuvre. The faster your steed is and more power it has, the more leeway you have for doing a low g gentle barrel roll.

[PS2A_yay!]

Aerocat has hit the nail on the head.

When doing a barrel roll in the PS2A I used to pull a consistant 3g throughout. The tighter the barrel becomes, the more g is required to maintain its shape. However less g will cause decreasing airspeed at the top point of the barrel, causing it to 'bottom out' severely. Remembering also the entry and exit altitudes of the barrel will be identical if coordinated.
The lesser g in the barrel can also be compensated by lengthening the barrel with a lesser roll rate.

The aileron roll as pictured above can be done correctly at 1g in most high performance aero aircraft, due to the requirement of only needing aileron to roll.

Either way, they can be both a hell of a lot of fun!!

[xer]

Seen it done in the 400 sim a few years ago with no problems.(Motion off of course)

[distracted cockroach]

A320 has been rolled in the sim by an experienced aerobatic pilot, with appropriate computers turned off.

[4Greens]

Barrel rolls in 707's were abandoned after a Boeing pilot threw an engine off.

[rmcdonal]

distracted cockroach: I was of the impression that couldn't do anything fancy in the Airbus due idiot proofing? Or is that the part of the sim they turned off?
Not having a go, just curious. :confused:

[distracted cockroach]

A320 has 3 levels of fly-by-wire redundancy "laws", Normal, Alternate and Direct, each with varying levels of protection. In Normal Law, "g", angle of bank and pitch protection would prevent aerobatic manoeuvers. When you begin to turn off flight control computers (or have failures) you end up in Alternate Law where most protections are lost (except load factor protection) This is the mode used in the sim for "unusual attitudes" and recovery, and it is definitely possible to roll the aircraft.
Cheers
DC

[Fantome]

When the RAAF operated 748s at Canberra in the VIP squadron a bloke named Gordon Terrell rolled one the day before his discharge. If I remember rightly he was a Kiwi and left to fly BAC 111s somewhere in the Pacific.

[Taildragger67]

Barrel rolls in 707's were abandoned after a Boeing pilot threw an engine off.

:eek:

In fact :eek::eek:.

[flog]

First up, an aileron roll must have a negative G component as you roll through inverted. I can't recall the last time I stood on my head and managed to land on the roof and stay there. No matter how fast you're rolling (and those new little buggers can get around in over 400deg per second), a roll will take you through inverted and into negative G territory UNLESS you apply a positive G vector onto the airframe. Now a Barrell Roll will allow you to maintain whatever G you require through the manouver as you ARE applying a positive G load onto the airframe at all times - through introduction of elevator.
You can do a barrell roll at 1G, or 2G, or 5G if you really hoiek it around. IF you've got the skill to pull it off. What must happen (especially in a 707) is for it to stay positive or else those little turbines under the wings are going to starve, flame out and you're going to have fun recovering.
O, and alot depends on the aircraft too. A low thrust Citabria might have to pull more G to get through the loop as it's only pulled along by 150HP. A 300 horsey single place Pitts (a la Bulldog, RIP) or Edge540 has the thrust to start level and pull the plane through the manouver without pulling much G. Thrust in a 707 last I checked was pretty significant, especially in Tex's case as there was only him and a few other bodies on board a very lightly loaded aircraft.

IMHO.

[Taildragger67]

If the a/c was loaded and not in perfect balance throughout the manoeuvre, could there not be a risk that the contents of the holds could hit the hold ceiling, potentially deforming it and thereby fritzing the control runs (leaving aside any crew and punters distributed across the cabin ceiling)?

[flog]

Not if he had at least +1G throught the manouver. Everything would sit on the floor just as if the aircraft was sitting at the ramp.
Lateral movement is still an issue, but Tex was (still is in fact, can anyone confirm he's still kicking?) gooood.

[Taildragger67]

Flog,

Indeed - that's my point - if it wasn't very well balanced throughout such that > +1g was maintained at all times, my thinking is you'd have containers punching through the cabin floor.

[AerocatS2A]

What does being balanced have to do with the g?

You don't need greater than 1 g, you need positive g. This means greater than 0 g. You can go over the top in a loop or barrel roll with less than 1 g, but as long as it is still positive, everything will stay in place.

First up, an aileron roll must have a negative G component as you roll through inverted.
Maybe a terminology issue here but to me you are describing a slow roll. A slow roll involves rolling through 360 degrees using rudder and elevator to maintain level flight throughout. In a slow roll you will transition from +1 to -1g back to +1g. The way I used to do aileron rolls, you'd pitch up a good 30 degrees or so, roll using ailerons only and allow the nose to drop through the horizon. Because the nose is allowed to drop you don't experience any negative g. The higher the roll rate, the less you need to pitch up to make it work.

[Peter Fanelli]

The China Airlines SP never flew again though...


Suggest you check your facts.

http://aviation-safety.net/database/record.php?id=19850219-0

Here is the aircraft as it is today.

http://www.airliners.net/open.file/0883168/L/

[First_Principal]

Barrel rolls in 707's were abandoned after a Boeing pilot threw an engine off.

Actually it appears it was't the barrel roll that ripped the (three!) engines off but rather an intentional skid/dutch roll (and not by the Boeing pilot who was on board either!). The 'plane flipped inverted and from that position the Boeing pilot took over and, according to one story, intentionally barrel rolled in order to recover the situation. He almost made it. There's a bit more information here (http://www.time.com/time/magazine/article/0,9171,892808,00.html?iid=chix-sphere) and here (http://aviation-safety.net/database/record.php?id=19591019-0) and here (http://en.wikipedia.org/wiki/Boeing_707)

[hoggsnortrupert]

Bob Hoover, Truely is:
Meet the man once when I was flying Commanders out of Wiley Post Bethany OKL, circa 86:
Man I wish I had made the most of the opportunity, to have his name in my log book!
As funny as it seems and I can not figure out why, but a prominent Aussie Aviator, and Instructor with his flying school at Bankstown, reminds me of him.
Every time I do a check with him I have to check myself, and not call him BOB?
I guess the man impressed me!:ok:
I must confess: The commander IS a JOY to fly! :ok:
( Anyone know of any jobs going on one?):ok:
Chr's
H/Snort.

[flog]

Aerocat,
The way I used to do aileron rolls, you'd pitch up a good 30 degrees or so

Damn terminology. I'd call this a really flat barrel roll if there was no negative G through it. But I see your point.

[Yakfivefive]

Bob Hoover


Now who cares about big machines rolling/barrel rolls the MAN Bob is my hero.

[ScottyDoo]

You can do a barrell roll at 1G

No, you can't.

[flog]

Quote:
Originally Posted by flog
You can do a barrell roll at 1G

No, you can't.

Ok, maybe not 1G, but well within airframe limits for almost anything (the Wright Flyer might have issues).

[404 Titan]

Some people need to have a good read up on torsional loading and what it does to an aircraft before saying things like:
but well within airframe limits for almost anything
:=

[flog]

Some people need to have a good read up on torsional loading and what it does to an aircraft before saying things like:

Some people are engineers with aero endorsments and know that a well executed Barrell Roll will effect no torsional load on an airframe beyond that required for a normal steep turn. You just happen to be changing the frame of reference through 360deg on the way through instead of staying in a level plane.

Edit - Why does this make me angry?

[404 Titan]

flog

And some people here use to be aerobatic instructors. First of all a barrel roll “IS NOT” a 1g maneuver. During any properly executed barrel roll or loop for that matter, the aircraft will experience up to 3g. The Airbus A340’s and A330’s I fly now are limited to +2.5g & -1.0g in the clean configuration and if I remember correctly most non-aerobatic light aircraft are the same. Now if you or some others here want to venture into the world of being a test pilot without being qualified, go right ahead. And before you tell me about Tex and the Dash 80 or the French pilot with the Concorde, they were both test pilots.
Aerobatic Figures
by Dr. Guenther Eichhorn
Barrel Rolls
The Barrel roll is a combination between a loop and a roll. You complete one loop while completing one roll at the same time. The flight path during a barrel roll has the shape of a horizontal cork screw. Imagine a big barrel, with the airplanes wheels rolling along the inside of the barrel in a cork screw path. During a barrel roll, the pilot always experiences positive Gs. The maximum during the maneuver is about 2.5 to 3 G. The minimum about 0.5 G.

[Wanderin_dave]

So you've got your 747 (or C172 for that matter) up and into the barrel roll and it falls out from the top......... 2 thoughts probably pop into your head.

"i wonder how strong this thing really is'' (you're about to find out)

and

''i wish i was in an aero's plane right now''

DON'T try aeros maneuvers in non aeros a/c!!!!!

[18-Wheeler]

So you've got your 747 (or C172 for that matter) up and into the barrel roll and it falls out from the top......... 2 thoughts probably pop into your head.

"i wonder how strong this thing really is'' (you're about to find out)

The Chinese found out accidentally that the 747-SP's can take up around 5G's without too much trouble. :)
3G's would be no big deal for a 747.

[404 Titan]

18-Wheeler

The 747SP owned by China Airlines that discovered Vmca after an engine shutdown in cruise never flew again. Structural damage to the wing caused by the high g’s and flight well beyond Mmo (just past Mach 1 infact) bent the main wing spar and caused deformation to the upper wing skins. So yes while it held together and proves Boeing builds a great aircraft, it also clearly demonstrates the dangers in flying an aircraft beyond its certified limitations.

[Peter Fanelli]

The 747SP owned by China Airlines that discovered Vmca after an engine shutdown in cruise never flew again.
Not true. Suspect you are thinking about the 727 that went out of control in the US.

From an earlier reply..


Suggest you check your facts.

http://aviation-safety.net/database/...?id=19850219-0 (http://aviation-safety.net/database/record.php?id=19850219-0)

Here is the aircraft as it is today.

http://www.airliners.net/open.file/0883168/L/

[404 Titan]

Peter Fanelli

I stand corrected. I suspect I have lost a few too many cells from the grey matter with the passage of time. Still the damage was substantial and clearly demonstrates the dangers when an aircraft is operated outside of its limitations.

DON’T DO AEROBATICS IN A NON AEROBATIC AIRCRAFT

[ScottyDoo]

Quote:
Quote:
Originally Posted by flog
You can do a barrell roll at 1G

No, you can't.
Ok, maybe not 1G, but well within airframe limits for almost anything (the Wright Flyer might have issues).


Not "maybe", definitely.

To change direction and maintain 1'G' is a physical impossibility.

Unfortunately, many pilots these days do not have a solid grounding in Physics as well as Mathematics. If they did, the afore-mentioned statement would be self-evident.

Many people seem to confuse performing a relatively low 'G' but constantly positive 'G' maneouvre with a fictional 1'G' maneuouvre.

[currawong]

I am performing a 1 g manoeuvre right now. By sitting here.
Pouring a coffee during a barrel role is feasible.
Pouring a coffee during an aileron role is not.
The last time I attempted a loop, it turned out, by definition, to be a barrel role.:}

[chemical alli]

tried it in the sim and found the 744 a little bit nose heavy coming out of it ,lots of warnings. anyway who cares its not intended to give the pax a thrill just get em from a to b

[Wombat35]

Almost Scotty...

I can change direction at 1 G... as long as I don't maintain level..


Currawong...

you can also do an aileron under +ve g at all times... you just can't do a level one. Start with the nose high and finish with the nose low... it's still an aileron roll as you are not looping.

Cheers Wombat :8