eugene@eos.arc.nasa.gov (Eugene Miya) (05/06/89)
From: eos!eugene@eos.arc.nasa.gov (Eugene Miya) If you follow up to this article, note that the distribution is usa only, please distribute followups as such. In article <6185@cbnews.ATT.COM> punch@tut.cis.ohio-state.edu (William F Punch) writes: >My father works for GE and had worked on those engines Interesting. B-1 production was set up to deliberately require parts from as many states as possible. It took 49, you can guess which state didn't contribute. >My question is how big a difference is there between the A and B? I >know the A was supersonic and the B subsonic, but how about payload, >range etc. What were the technical reasons for changing the B to >subsonic (or was it all just political/money)? Does the B1 program >suffer a lot from getting only B's instead of the original A's. Most of the changes were with avionics, a few small aero changes (blunter snout). Much had to do with change of mission to a cruise missile platform. It got heavier. Minor stuff. >To stretch things even farther, how different is the B1A from the >original XB-70 (range, payload, speed)? Were any of the results from the >B-70 program used in the B1, or was all that lost? Why was the B-70 >cancelled (I remember a crahs but assume the cancellation was politics). The two planes had completely different missions. They were designed at the same site, North American Aviation Los Angeles Division which became NA Rockwell, and now Rockwell Intl. Also the site of the P51, etc. The B-70 began as a fast, high-altitude delivery system. It was designed to fly at the limits of turbojet engines using new concepts like riding (catching lift) its shock wave. What shot it down was Francis Gary Powers U-2 flight when he got shot down over the SU. That was the death of high, fast bombers. Very evident. The delta wing design made slower, lower altitude flying difficult (less stable). Starting the engines was quite a sight. Its design did contribute to the two American SST designs. The B-1 is a low flying, slower, low-signature pentration plane. It gains stability using a variable geometry (swing wing) with many fighter like features. The B-1 is a smaller plane in several ways, but has a great carrying capacity considering its size and weight. The B70 was never finally rated for payload since the program was canceled, but you can look up projected figures (more than B-52), also the improved yields of new weapons made the big capacity less necessary. All planes contribute something to the understanding of future planes. Very few of B-1's engineers were B-70 people. There was about a 10 year difference in design time. I believe a total of about 50,000 engineers were employed by B-1 at its peak. Thousands in the hanger I used to work in. We also had one of the more advanced CAD/CAM systems at the time (early 1970s). The B-1 is indicative of "build a plane of many small parts" philosophy. The Shuttle is a result of this philosophy. In contrast is the Boeing, few, complex but big parts machined from a block of aluminum. Exercise, what philosophies are McD/D, Lockheed, Northrup, G/D? There's lots more, that is Rockwell's responsibility. You can write Rockwell at LAX and probably still get B-70 (and B-1) info (I did when I was younger). Longish signature follows "Type 'n' now" Another gross generalization from --eugene miya, NASA Ames Research Center, eugene@aurora.arc.nasa.gov resident cynic at the Rock of Ages Home for Retired Hackers: "You trust the `reply' command with all those different mailers out there?" "If my mail does not reach you, please accept my apology." {ncar,decwrl,hplabs,uunet}!ames!eugene Live free or die.