t-scotta@uunet.uu.net (06/08/91)
From: microsoft!t-scotta@uunet.uu.net Steve Williams commented in his article, "I don't think that the B-1 has a poor history of reliability. It is an unusual plane, pushed to the maximum limit of performance. One example is the unusual design of its fuel tanks which has to be incorporated into its swing wing design. Its leaking fuel problem is nothing unusual." Have I missed something or do all swing wing aircraft leak fuel. I don't think that the F-14 or the Tornado, to other swing wing aircraft leak fuel to any noticeable extent. True, these planes are fighters(well ok interceptors), and are lots smaller so there is less stress at the wing/fusalage(sp) joints. But the basic design(swing wing) is the same. Another aircraft that is well know for leaking fuel is the SR-71. However, this was designed in on purpose because of the extreme temps. in which it operates. On the SR-71 at speed, the metal heats up, expands, and seals the tanks. I don't believe the B-1B can fly fast enough to generate the required heat for that to happen. Also, the fuel involved is an important factor. The SR-71 fuel is rather special. It is my understanding that even a lit match dropped in, say a pool of SR-71 fuel(JP-7??), will NOT cause the fuel to burn. So lots of SR-71 fuel on the ground is not problem, as opposed to lots of standard jet fuel on the ground, which is much easier to light, and is an easy way to loose a good ground crew. :) I think that the B-1B has some signifigant problems that really need to be sorted out. If the AirForce is forced to ground all of it's B-1Bs then there is something really wrong with the plane and in my opinion should be fixed. Once these problems are corrected, the B-1B will be able to prove itself as a good airplane. Scott Avery No Flames intended or implied My opinions are all my own.
yarvin-norman@CS.YALE.EDU (Norman Yarvin) (06/11/91)
From: yarvin-norman@CS.YALE.EDU (Norman Yarvin) microsoft!t-scotta@uunet.uu.net writes: >> Its leaking fuel problem is nothing unusual. > >Have I missed something or do all swing wing aircraft leak fuel. As I understand it, fuel leak problems are common during development of aircraft largely because of the use of fuel tanks integral to the wing. This means that the same surface serves as a wing, which means it is stressed by airflow and bends to take up the stress, and as a fuel tank, for which it must be hermetically sealed. I presume swing wings exacerbate this problem because the pattern of stress changes as the wing moves. Jet aircraft generally carry monstrous amounts of fuel; their wings are practically huge fuel tanks. Leaking fuel is unacceptable in an operational aircraft, but as a development problem it is not an indication of the designers' incompetence. -- Norman Yarvin yarvin-norman@cs.yale.edu