wb9omc@ea.ecn.purdue.edu (Duane P Mantick) (10/18/89)
From: wb9omc@ea.ecn.purdue.edu (Duane P Mantick) Since many people seem to have an interest in the XB-70, I think perhaps some documentable information may be in order. The following has been gleaned from "Wings" magazine, February 1986, Volume 16, no. 1. Much of what is in the article is derived from USAF or from North American Rockwell and/or subcontractor files. I suspect that it is probably 99.9% accurate. To avoid sucking up TOO much bandwidth, I will simply state certain items that seem of relative importance or are relevant to previous discussions in this newsgroup. XB-70A #1 was rolled out May 11 1964. It was the result of competition primarily between North American and Boeing for the WS110a (Weapons System) contract, which goes back to the early 50's. The engine was the General Electric YJ93-GE-3 which was an enlarged J79 - it had Mach 3.2 capability at 90,000 feet. Rated in the 30,000 lb. thrust class. The *cancelled* YJ93-GE-5 high energy boron fuel version was similar. (note: that is to say it was never implemented or used in either ofthe XB's, as far as I can tell) Engine was designed to operate continuously in afterburner and used JP-6. North American also designed a fighter around this engine, the Sabre III, which lost out to the F-15 Eagle for production. The secret to much of the XB-70's performance was "compression lift". This meant essentially that the aircraft rode on part of it's own shock wave; the design numbers indicate that when compression lift and the hinged wingtips were combined, 30% of the 500,000 lb weight of the aircraft was neutralized at high speed. Initial contract let out to North American on Jan. 2, 1958. "Boeing would build the wing, LTV the leading edges; AVCO the aft upper fuselage; AiResearch the central air data computer; B.F. Goodrich the wheels and brakes; Cleveland Pneumatic the landing gear; Curtiss-Wright the folding wingtip actuator system; General Dynamics the main wing stainless steel sine-wave spars; Hamilton Standard the environmental control system; Liquidometer the aircraft's fuel management system; IBM its bombing/navigation system; Sperry its inertial platform. There were 2000 principal suppliers participating in the North American WS-110A program." The name Valkyrie came from a USAF service-wide name-the-plane contest, which was decided on July 3, 1958. "In Norse mythology, Valkyrie is a beautiful hand maiden of the gods, who roams the skies on her galloping steed and decides the outcome of battle." The boron fuel project was killed by GE on August 10, 1959 as being too expensive and "smoky". There were three 28 foot diameter braking parachutes for landing purposes as well as 84 stationary and 80 revolving brake discs. XB-70A-2 was rolled out May 29, 1965. It was generally reckoned to be the better of the two as it had a 5 degree wing dihedral, an automatic air induction control system (to slow the supersonic air to subsonic speeds before feeding it to the engines) and an increased fuel capacity. #2 spent a total of 1 hour and 37 minutes at the design speed of M3 as opposed to only 2 minutes for #1. #1 was later refitted with the auto. AICS system. A recon version of the XB-70 apparently bit the dust because the CIA's A-12 (forerunner to YF-12 and SR-71) had flown on April 26, 1962; 29 months BEFORE #1 XB-70's first flight. The SR-71 flew December 22, 1964 - meaning the USAF had three high altitude M3 recon units before the XB-70 even demonstrated that capabliliity. The article is quoted as saying that the A12 could provide the recon at a lower cost than any part of the XB-70 program could. Another cancelled program offshoot was the Model NA-257, or F-108 Rapier, on September 23, 1959. This was a proposed M3 long range interceptor. Structually the same as the XB70, the F-108 would have been powered by two of the J93-3 engines - capable of M3 at 80,000 feet. Scheduled to fly in March of 1961 it was cancelled in the mockup stage. Quite possibly this was due to the YF-12 program. A side note: the YF-12 used the same radar, fire control system and armament that the Rapier would have had. The B-70 program was cancelled December 3, 1961, article states: "There was no ignoring the fact that Russian anti-aircraft missiles could hit and bring down any high flying target, no matter how fast or sophisticated." (note: I wonder about that......) Despite the cancellation some work went on that resulted in the two XB's that we know flew, and one YB-70. The YB was being built when it was axed on March 5, 1964. The accident. June 8, 1966 during a photo seesion, an F-104 Starfighter piloted by Joe Walker struck the right wing tip, rolled onto its back, took chunks from BOTH vertical stabilizers, hit the left wing tip and then exploded and crashed into the desert. The #2 XB flew on for 16 seconds before it snap-rolled and went into a dive. Pilot Al White was able to activate his encapsulation system although his right arm was caught between the ejection hand grip and upper capsule door - when he yanked his arm inside, he separated his upper arm from the shoulder socket (ouch!). He received additional back and internal injuries because the shock pad on the bottom of the capsule did not open and the impact bladder didn't inflate. It has been estimated that he hit the ground at 43 g's........ Major Carl S. Cross did not eject, for whatever reason, and went down with the ship, so to speak. First flight of #1 on September 21, 1964 lasted one hour and 7 minutes. Second flight of #1 on October 5, 1964 lasted 55 minutes. Third flight of #1 on October 12, 1964 lasting 1 hour and 35 minutes - first supersonic flight. Fourth flight on October 24, 1064 flying supersonic for 40 minutes including cycling the wing tips. Fifth flight on February 16, 1965. Eighth flight on March 8, 1965 attained Mach 2.14. First flight of #2 on July 17, 1965. 17th flight of #1 on October 14, 1965 first M3+ flight (M3.02 attained) at 70,000 feet. 17th flight of #2 on January 3, 1966 Mach 3.05 at 72,000 feet. ??th flight of #2 on February 17, 1966 was heaviest takeoff at 538,310 lbs. ??th flight of #2 on March 19, 1966 was highest flight at 74,000 lbs. ??th flight of #2 on April 12, 1966 was fastest at M3.08. ??th flight of #2 on May 19, 1966 was longest sustained M3+ for 32 minutes over 8 western states. 46th flight of #2 on June 8, 1966 was its last. Accident. #1 had been limited to Mach 2.5 because of skin losses during high speed flights. 83rd flight of #1 on February 4, 1969 lasted 3 hours 19 minutes going from Edwards AFB to Wright-Patterson AFB where the XB-70 was presented to the USAF Museum. Pilot Fitz Fulton, copilot Ted Sturmthal. The two aircraft flew 129 times totalling 252 hours 38 minutes. Of that, 145 hours 28 minutes was subsonic, 55 hours 50 minutes supersonic. For the scale modelers amongst us, the tail number on #1 is 20001 while on #2 it was 20207. Many of #1's test flights were done in cooperation with NASA and thus the craft had the yellow-stripe NASA logo painted above the tail number (YF-12 had virtually the same marking during its stint as a test aircraft). Note also that the only other obvious identifying feature between the two was the black radome on the bottom of #2's nose; #1 was all white in this area. There also appears to have been one of the old round NASA logos on #1 just below the left side cockpit window - this was also used below the right cockpit window during that phase of it's life. When I went to the USAF museum and saw #1, I was struck by the fact that this aircraft was actually 1950's technology! To say the least, one wonders what such an aircraft could do if built with the technology acquired over the last 30 years. Composites instead of steel honeycomb, for example. Improved engines and electronics.... anybody care to speculate on possible performance? Anybody care to speculate on the price? Duane
military@cbnews.ATT.COM (William B. Thacker) (10/20/89)
From: att!dptg!ulysses!smb > The B-70 program was cancelled December 3, 1961, article states: "There was > no ignoring the fact that Russian anti-aircraft missiles could hit and bring > down any high flying target, no matter how fast or sophisticated." (note: > I wonder about that......) Remember when this happened, only a few years after a U-2 was shot down over the USSR. That wasn't really supposed to happen, either. But Soviet missile progress outstripped U.S. expectations. It probably didn't to make the same mistake in judgement again.
dep@ius3.ius.cs.cmu.edu (David Pugh) (10/24/89)
From: dep@ius3.ius.cs.cmu.edu (David Pugh) In article <10406@cbnews.ATT.COM> military@cbnews.ATT.COM (William B. Thacker) writes: >Remember when this happened, only a few years after a U-2 was shot >down over the USSR. That wasn't really supposed to happen, either. >But Soviet missile progress outstripped U.S. expectations. It >probably didn't to make the same mistake in judgement again. Was the U-2 really shot down? I've heard an alternate theory that the U-2 had either a mechanical problem/structural failure/etc. Arguments for the later theory included: o No intelligence on the Soviets having a missle capable of downing a U-2. o No other downed U-2s (the US stopped overflights over the USSR, but Soviet clients could have probably gotten the SAM and had lots of opportunity to use it). (I know the Soviets claimed to shot the U-2 down, but that makes better press than saying it fell out of the sky. Probably much more acceptable to Congress-critters too.). -- ... He was determined to discover the David Pugh underlying logic behind the universe. ...!seismo!cmucspt!ius3!dep Which was going to be hard, because there wasn't one. _Mort_, Terry Pratchett