Could you do this in a 747-400?

[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.





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)



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.

[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.

In fact .

[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/...?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 and here and here

[hoggsnortrupert]

Gentleman:

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!
I must confess: The commander IS a JOY to fly!
( Anyone know of any jobs going on one?)
Chr's
H/Snort.