In one of those Concorde movies, it shows the plane doing a full loop. Is this possible? Also, in another movie (but it could have been the same), someone mentions something about inverted flight tanks. So, I’m presuming that planes that have to ability to fly upside down have these inverted flight tanks?
Inverted flight tanks? No idea. I am sure a concorde could roll and fly inverted, although I don’t know for how long. As for looping, it probably could, but it would have to be a pretty big loop so it didn’t get too g loaded… Actually, the more I think of it I am not so sure if it could. The Olympus engines are horribly inefficient at lower (sub mach) speeds, and it only breaks the sound barrier at FL350 or so if memory serves. Maybe if it used its burners in a lower altitude? Hmmmm… I don’t know for sure. It would also have to be more or less empty with little fuel as well, I think. I would say a definite maybe. 
Eric
Little OT, but in the same vein:
Back in the '70s, during the testing program, a Boeing test pilot did a full barrel roll in a 737 :eek: (empty, of course). He said it was fun, but he didn’t want toever try it again.
You’re both missing the important questions: Could it loop or fly upside down supersonicly?
Thanks for the quick reply, bernse.
But, I should probably elaborate on the inverted flight tanks thing. I think what the movie meant was, if a plane were to fly inverted, the fuel inside of the tank would shift, so as to not come into contact with the fuel pump, and thus, there’d be no fuel to power the engine while inverted.
So, I’m assuming that these inverted flight tanks have fuel pumps on both sides of the tank, but of course, that’s just a big guess. I’m completely talking out of my ass here. So, hopefully someone will come along and straighten everything out.
Actually it was a 707 prototype in 1955. See “Tex” Johnston’s obituary here:
http://seattletimes.nwsource.com/news/local/html98/tex_103098.html
Loop while supersonic? No way. It would have to be such a big loop so it wouldn’t bust up on the ascent, the aircraft would certainly stall.
Roll inverted supersonic? I suppose it would be possible, but I would think the craft would also possibly bust up because I think there would be a very real possible the pilot would loose control doing it. The pilot would have to nose up more than usual to avoid losing to much altitude in making the roll. However, I think that since he would be doing over mach, his altitude would very rapidly increase. Likewise, if he didn’t nose up enough, his altitude would fall like a rock in process of doing the roll. I am not an aeronautical engineer, but I would have to say my best guess would be theoritically possible, but not bloody likely, from my meager experience (having only flown a small, single engine aircraft).
Eric
Aw, you don’t have to go all the way to Seattle for that story. It’s right here in Cecilville. Great link, though.
A correctly performed barrel roll is quite a bit different than conventional slow rolls and can be performed by a lot of non-aerobatic planes. Moderate, positive G loads are maintained throughout the maneuver so the plane never “feels” upside down and inverted fuel or oil systems aren’t needed. I’ve seen films of the interior Bob Hoover’s Aero Commander showing a glass of water that never spills through a complete roll though earth and sky swap positions outside.
A barrel roll in a heavy may not be as violent as Patty Wagstaff doing a snap roll in her Extra 300 or the late Art Scholl doing a lomcevac (sp?) in his Chipmunk but it’s still pretty damn cool.
I’m quite sure a talented pilot could perform barrel rolls with the concorde at Mach speeds. But I have very serious doubts whether the structural integrity of the concorde could handle a loop de loop. The concorde was designed to go fast, not to be a stunt plane.
However Boeing claims that the structure of their line of planes—say a 747—could handle a loop. I’m not sure if they’ve tested this though.
Inverted tanks:
Regular fuel tanks have the fuel lines connected to a very low point in the tank (not the lowest - sediment collects there). If you roll inverted and the tanks aren’t absolutely full, the fuel intake will be in dry air and the engines will run out fuel once the lines empty.
Aerobatic planes that fly inverted can solve this problem several ways. One is to have a flexible hose with a weight attached to it. That way, no matter which way the tank is oriented the fuel pickup will be near the bottom.
Another way is to have a small header tank with a pickup in the middle, so that if the airplane is inverted the engine will keep going for a fair length of time.
Big jets don’t have any of these devices, so if you rolled one inverted they would probably start flaming out within perhaps a minute or so.
Another OT along the same lines, I’ve read that nuclear B-52 crews were at one time trained to do an Immelman (half loop, followed by a half roll) as a method of avoiding the blast of their own bombs. Apparently they stopped practicing it because it did put a lot of stress on the airframe.
This isn’t necessarily true. As Padeye pointed out, an aircraft can fly inverted without the need for a specially designed fuel and oil system by performing a barrel roll. In a barrel roll the pilot flies the plane around the axis of rotation, as if inside a barrel. During this maneuver the plane only experiences positive G’s.
This is what the previously mentioned Tex Johnston claims he did with the Dash-80 when he rolled it during a test flight.
I’ve read accounts of an AC-130 gunship (C-130 turboprop cargo plane with lotsa guns hanging out the left side, for close air support) doing a split-S (half roll to inverted, nose over into a dive, half roll and pull up to fly level again) to avoid a surface-to-air missile. Tossed the gun crew around a little, but came through unscratched. Of course, Hercs are unusually spry for heavies.
I think rolling or looping a Concorde (especially trying a roll at supersonic speed) would give you nothing but Concorde chunks falling into the ocean. I’m quite sure the wings would rip right off. Maybe a low speed roll, like the 737 stunt (and he did THAT right over Seattle!) would be ok, but the Concorde was designed for fast, straight flight. We’re not talking about an F-16 here…
Brian Trubshaw barrel rolled Concorde during test flights from Filton Bristol.
In case you hadn’t heard, it looks like noone will ever barrel roll a Concorde again. It’s looking more and more like the Concordes will all be heading for aerospace museums or the scrap yard.
Well, its not even close to a done deal by anymeans. If it does end up that way though, what a bloody shame. Those are about the most beautiful aircraft ever built.
Eric