Is Boeing finished?

Interestingly it was the Russians who developed the industrial techniques for titanium structures. Indeed they had build titanium-hulled submarines (in the early '80s) befire we made even much progress in using the metal on aircraft structures. (Boeing's variable sweep winge SST design was abandoned because of reoccuring cracks in the titanium wing root structure & hinge.

A decade ago Airbus was well ahead of Boeing in applications of composite structural components. They chose to invest their money into a larger-than-ever aircraft usung marginal improvementsd in existing technology. Boeing chose to invest in significant improvements in the basic technology and apply it to cionventional fuselage designs with upgraded aerodynamics. It appears that the payoff on the latter bet will be greater and more reliable than the former.

I must admit I was impressed with the A380 when I first saw it fly. The hiccups in delivery schedules are only to be expected, annoying though they are. But the basic question has still to be resolved...is the future of air travel shifting large numbers hub to hub or smaller numbers direct. [That is if you think air travel as we have know it has[/i] a future. I wouldn't buy airbus or boeing.]

The SR-71 was all titanium in 1958. It leaked like a sieve until it got up to speed and the Ti expanded. We knew alot about Ti but only with TiGR composites do we have a strong as steel, light as AL material
I recall the disaster that the Russians had with the nuclear sub Komsomolet, which sunk almost like the Vasa . It was double hulled with an inner hull of Ti.. Stress cracks were shown on that baby and it wasmostly because they machined the incorrect tolerances and didnt allow for Ti's great expansion coefficient.

I imagine that only wings and tails and trailing pieces will be TiGR. Otherwise the plane fuselages will be taking on rather bizarre shapes to accomodate the expansions. I always thought that the composite used in the shape they had developed in the "Aurora" was nifty, sort of a triangular X-section, that way the Ti/graphite could be used and expansions could be accounted for in a non stress inducing cross section.

Its interesting how new materials are literally at the cutting edge of engineering design. I remember how Rolls Royce were pioneers with carbon fibre for jet fan blades as far back as the 1970s. That was for their RB211 engine if memory serves correctly. It was a disaster...it nearly bankrupted the company. It served as a salutory warning. But the engine was a success with conventional nimonic type alloys.

I'm fascinated by the potential for carbon nano tubes. It could make possible the space elevator. Arthur C Clarke said it would be built 50 years after people stopped laughing. How about gently lifting vitrified radioactive waste from nuclear power production gently into space then dumping it in the sun?

Nuclear waste disposal problem solved.

However, back to aeorplanes. You mentioned Aurora Farmerman. Is that just a concept or is it real. And what is it exactly, some sort of scram jet powered aircraft?

Aurora is one of the worst kept secrets in our development programs. Its a severely swept delta wing with no vertical stabilizers. Its supposedly a TiGR composite "wing" and its got 2 engines a standard and a (ithink) scramjet. so its supposed to be superfats, but remember, we had the SR-71 and that is one bigass momma with an incontinence problem. We saw it when they brought it to Dulles and then to the air museum outside of DC. I think its top "official" speed was almost 2500mph (mach 3.3 and could cruise all week at 3.2). The only reason it couldnt fly faster was that it had a functional speed brake that was allowed to kick in when skin temps got over 400 degrees C


because of its design, the blackbird used to burn JP-7. You can actually extinguish a fire using JP-7 (well you could put out a butt in it).
I reacll that some **** we used to use to set off mine charges where we didnt want to pollute the minepool water with deisel. We would shoot tetraethyl borane at the shotholes of PETN. They would shoot tet borane into thgeexhaust nozzles of the blackbird just to start it up.

One of the intended economies of the A380 was to be its capability to deliver more passengers per landing slot at the already traffic-choked major airports capable of handling the beast. The term "Landing Slot" does not refer to a parking place on the ground, it refers to the required plane-to-plane in-air separation within the approach and landing corridors. Essentially, the smaller the leading plane, the more closely a following plane may position itself in the que. Its a little more involved than that, but that's close enough to get the idea across. The problem is turbulence, and the bigger the plane, the greater, and longer-lasting, the turbulence in the wake of its passage through the air. If you watch landing ops at a major commercial airfield, you might see a couple light commuter aircraft land fairly close in time to one another, the lead plane just turning from the main runway onto a taxiway as the follow-on plane touches down. Next in line might be a mid-size airliner or two, one following the second commuter plane fairly quickly, with the second airliner noticeably further spaced, landing a relatively good deal later than its similarly-sized predecessor, which, btw, will leave the main runway via a taxiway further down than the one used by the lighter commuter planes. Now, lets drop a heavy into the pattern. The heavy will be spaced according to the aircraft in front of it, but it will be noticeably longer yet before the next plane, regardless of size, follows on, and if, as often happens, the next happens as well to be a heavy, there will be yet more delay, before it touches down, and still longer delay before anything follows it onto the runway. The heavies also will be using the taxiways most distant from the touchdown area. The A380's size - with its resultant greater wake turbulence - has resulted in its type being assigned what amounts to 2 landing slots following just-completed airworthiness tests of the flying prototype.

The A380 generates yet more turbulence:



What we seem to have here is Moby Jet, with the EADS directorship playing Ahab tangled in the lines.

BBC: Aurora ???

Watch the video after reading the article - pretty neat.

As FM says, Aurora has gotta be the worst-kept secret the Airforce has.

GoogleSearch: Plane Aurora Secret

The SR-71 also evolved out of a "black program" (i.e. no budget line item, secret management & oversight), then called the YF-12A, a supposed advanced fighter. In addition to the then new structural and engine inlet technology, it introduced stealth technology, particularly involving the concept of designing the aircraft shape as an equivalent corner reflector, confining reflected RF energy to intense narrow beams. All of this was closely guarded for quite a long time. The titanium technology was not available to Boeing in 1967 as they struggled to fabricate a titanium wing box and hinge for their initial SST design.

Information on these things inevitably leaks out over time, but in fact a good deal of it was kept secret for a long time. Same with Aurora. The antecedents to this project started over 25 years ago.

Interesting commentary about the wake turbulence from large aircraft by timber. A key element of it for landing aircraft is the large vortex shed by any aircraft the moment the nose is dropped on landing and the wing ceases to produce appreciable lift. The strength and duration of this vortex is directly proportional to the lift or weight of the landing aircraft. The same phenomenon occurs at takeoff as the nose is rotated, and because the aircraft is then full of fuel, the shed vortex is even stronger. On a dry dusty day you can literally see these standing vortices just above the runway. Not too much of a problem for similarly sized aircraft, but a very big one for smaller aircraft following a large one. Timber's point about "slots" is indeed correct and it also slows departing aircraft from the same runway.

I don't think that hub and spoke air route networks will ever disappear completely. However the trend over recent years has been decidedly to reduce their concentration as major hubs are served by increasing numbers of airports in the region and by low-cost airlines generally focusing on point-to-point networks..

In any event it seems fairly clear that the forecasts of Boeing's imminent doom were very far off the mark.

Couple years back, at Oshkosh, I had occasion to find my Orion much more involved with the wake turbulence of a C5A than I had anticipated - even several minutes behind the behemoth, just crossing its wake, the ride was a real attention-getter.

I'm sure it was - in a light. low wing loading aircraft. My (limited) experience in them is that you are wrestling with even light gusts all the way to touchdown. A 35,000 lb fighter at 130Kts just plows through that stuff: same with even a 737 or an A330.

1 does this vortex condition mean that only specific airports will be usable for the A380? Im thinking Bangor Maine (11000 ft) or Dulles?. Cant they make the thing with a variable sweep wing ?

I think timber's description of the effect on aircraft route and terminal operations was accurate. Some airports may choose to use one runway for 'heavies' and another for smaller aircraft, but in any case the mimimum interval between landing and departing aircraft on the same runway will have to be increased when one is a 'super heavy'. Because the main terminals in the world; LAX Frankfurt, etc generally operate so close to capacity this will have upstream effects on traffic flow, more or less as timber described it.

The vortex thing is an interesting (to me) feature of fluid mechanics. In a free fluid vorticity or circulation is conserved (basically conservation of angular momentum). The flow over a lift-producing wing can be represented as the sum of a linear flow equal to the aircraft speed and a circulating flow around the wing (in effect increasing the velocity on the top surface of the wing and decreasing it on the bottom. The "vorticity", or the mathematical line integral of velocity on any closed path surrounding the wing (cross section), is directly proportional to the lift produced by the wing. The conservation principle means, for example, that, at the moment of rotation on takeoff, an aircraft sheds or leaves behind a vortex equal in strength and opposite in rotation to the the one that remains with the wing as it is rotated to a positive angle of attack relative to its forward motion. The same thing happens at touchdown. These shed vortices are real and for heavy asircraft they are powerful. Moreover they can behave as a fairly rigid body for 20 or 30 seconds as they dissipate. I recall once taxiing out for takeoff at MCAS Yuma Arizona as a heavily loaded C-5 took off. You could vividly see the shed vortex in the swirling dust of the desert around the runway- it lasted for almost 40 seconds. I took my time in calling for takeoff.

I deal in Darcy flow and viscous flow. I have no use for high Reynolds numbers Thanks for the info, is The A380 a bigger gamble than they figured?

All the really interesting stuff happens at high Reynolds numbers. (I did my disertation on turbulent viscous flow). What is Darcy flow? You know a lot of stuff I don't.

I suspect that in the long run the A-380 will indeed achieve a degree of success. However I doubt that it will end the market for smaller aircraft, including tho 747 & 777 & the like, as was suggested by the author of this thread. It is interesting that a lot of these things were also said about the 747 when it was introduced, but it has been a long-term success for Boeing.

One interesting factor is the fact that as a structure gets larger, it gets weaker. The remedy is added structural weight relative to fuel and payload. The 747 worked because Boeing figured out a way to control wing flutter with less structural weight. Subsequent advances in materials, as already discussed, have lilely enabled another large step forward, perhaps for the A-380, but there is an ultimate limit out there.

The question of the moment is whether it is more advantageous to use the new, lighter materials to lower specific fuel consumption, or to build a significantly larger aircraft. Recent trends in fuel prices suggest the former, but much depends on the relative details of performance of the competing new aircraft.

Just a hunch, and years if not decades from finding out, but its my guess we've pretty much reached the practical limit of scale with conventional wing and fuselage designs. Without absolutely astounding advances in materials, the blended wing/lifting body concept seems to me to offer the best bet for quantum increase in airframe payload capacity.

Probably true if you want supersonic or high subsonic speeds. If you are content with a true airspeed of 470Kts (today's aircraft), it's hard to beat a high aspect ratio moderately swept wing and high bypass ratio turbofan engines. Lighter structures will reduce fuel consumption, and in today's conditions that's a benefit that is hard to pass up.

sO MACH 8 is a functional problem because of friction heat? Unless we start making the entire plane out of ceramics Isuppose. TiGR is a great heat sink buit it lights up like a flare gun if it gets over 650C (same temps as melting of alpha quartz, thats why they sometimes are found together in ore bodies.

Georgeob Darcy flow is at reynolds numbers well below 1, where viscous forces exceed dynamic forces and we consider laminar flow as lightnin speed..
All ground water equations (with exception of fractured rock formations) use DArcy's LAw , drumhead theory and /or rely on expansion of water. an "expansionless " medium.

I did my dissertation on transport of dissolved rare earth elements in ground water so Im mostly a slow fluid guy with high hopes of hitting paydirt in the ppm range. Thats where my chem morphed into geology. Never looked back, cause I cant stand workin indoors for more than a week at a time.

The flow of cold molasses or liquid glycerine around around an obstacle?

I have scanned some groundwater models that use the diffusion equations (Ficke's law) to model the spread of contaminants. "Where are the transport terms...?", I thought. "How do they know there are no liquid flows (i.e. at real Reynold's numbers)? I guess the answer is in your phrase "except fractured rock formations. Interesting. Mostly I am concerned that the bastards are fulfilling the contract and making money. Perhaps too bad.

Try hiring a govt agency like the USGS to generate a model, youre grandchildren may not see a product..

As Fickes second law says. "chemical diffusion cannot proceed as fast as the water flowing in porous media because the ions in solution are always stopping to get a cappucino or justgetting lost by taking "short cuts"." Of course I changed some of the more quantitative aspects for clarity. Thats why we make up models, we use them to try to explain why things are taking so damn long.

If you need me to explain this to your hydrogeologists , I have a Powerpoint demo that I use for Community groups and boyscouts. :wink:


I will now return you to your own previous wisecracks.

I have no further comments about the fate of aircraft companies or about the A380, except these two points

Do you think planes will ever get as big as cruise ships?

I shall never get my head full of my own inflated self worth because, although a large part of my work is to provide sources of Ti ores to various international companies who make sheetstock for things like airplanes and fountain pens, the other portion of my product is used to make white paint for barns and window sills and white pigment for paper.

Good posts guys interesting reading. Yes titanium oxide is very white. A380 very big. George, I asked the question is Boeing finished a year ago and it was based on the premise that either Boeing or Airbus had called it right ref hub to hub or direct flights. The jury is still out. However, what I did not of course anticipate is that Airbus and its holding company could be just as venal corrupt self serving and nepotistic as anything in the US