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XB-70 Valkyrie

Unread postPosted: 19 Nov 2004, 22:11
by habu2

Unread postPosted: 19 Nov 2004, 22:12
by RyanCollins
Thank you, habu2... :)

But, what happened with the Valkyrie...? (I don't know much about it...)

Unread postPosted: 19 Nov 2004, 22:24
by Occamsrasr
Two B-70s were built. One, AV2, crashed in the desert on June 8, 1966 after participating in a "General Electric" photo shoot. Several GE powered planes got in formation to take pictures and a F-104 rolled over the top of the B-70, killing the pilot of the Starfighter and causing the B-70 to spin. The pilot survived but the co-pilot did not.

AV1 was retired to Dayton, Ohio for the Air Force Museum in February of 1969. It is still there, by the way.

The B-70 was designed to study the effect of compresion lift at high speeds, and as such had wingtips that folded down. The B-70 incorporated 6 YJ-93 turbojets, a derivative of the J-79 core.

The Soviet Union developed the MiG-25 to counter this threat, even though the B-70 program was canceled.

I am sure there is lots more but that was all from memory.

Unread postPosted: 19 Nov 2004, 23:21
by RyanCollins
This is what I founnd about the specifications of XB-70

North America XB-70 "Valkyrie"

Specifications:
Span: 105 ft.
Length: 185 ft. 10 in. without boom; 192 ft. 2 in. with boom
Height: 30 ft. 9 in.
Weight: 534,700 lbs. loaded
Armament: None
Engines: Six General Electric YJ-93s of 30,000 lbs. thrust each with afterburner.

Performance:
Maximum speed: 2,056 mph. (Mach 3.1) at 73,000 ft.
Cruising speed: 2,000 mph. (Mach 3.0) at 72,000 ft.
Range: 4,288 miles
Service Ceiling: 77,350 ft.

I got this pictures of the "front view of the XB-70 with all three wingtip angles":

Unread postPosted: 20 Nov 2004, 01:19
by habu2
My pics of AV-1 at WP USAF Museum are here

Image

The XB-70 program was really killed by the development of the ICBM, in addition to being way over budget and the fallout from the crash/loss of AV-2.

Unread postPosted: 21 Nov 2004, 02:34
by TC
Also, the latest Soviet SAM (I believe SA-2) was another factor that led to the B-70's cancellation. I have heard that the program was actually cancelled before the midair, which by the way killed test pilot Joe Walker. Walker was the chief test pilot in the X-15 program after Scott Crossfield left the program. The Valkyrie was/is a beautiful jet though, still one of the best looking planes ever built, in my opinion.

Beers and MiGs were made to be pounded!

Unread postPosted: 21 Nov 2004, 09:15
by KarimAbdoun
Just to get something straight, the XB-70 was an X-plane, experimental not an operational bomber?
Just to be sure

Unread postPosted: 21 Nov 2004, 19:59
by habu2
Not officially one of the research "X-Planes", the X prefix did denote prototype/experimental though. NASA later used AV-1 as a research aircraft, but it was never one of the "X Planes" like the X-1, X-15 etc.

Midair refuel TSR.2 and XB-70

Unread postPosted: 23 Jul 2007, 19:02
by bdn12
Did the XB-70 and TSR.2 have the ability to aerial refuel?

RE: Midair refuel TSR.2 and XB-70

Unread postPosted: 24 Jul 2007, 04:03
by habu2
I don't know about the TSR.2 but the neither of the two XB-70s had provisions for inflight refueling. The third XB-70 was to have a refueling receptacle forward of the windscreen and was to test supersonic refueling, but the program was canceled before #3 was built.

RE: Midair refuel TSR.2 and XB-70

Unread postPosted: 24 Jul 2007, 08:30
by snypa777
TSR.2 had a retractable IFR probe on the left of the forward fuselage.

http://www.vectorsite.net/avtsr2.html A good TSR.2 page.

RE: Midair refuel TSR.2 and XB-70

Unread postPosted: 24 Jul 2007, 13:30
by johnwill
Habu2,
If the XB-70 was to test supersonic refueling, what were they planning to use for a tanker?

Re: RE: Midair refuel TSR.2 and XB-70

Unread postPosted: 25 Jul 2007, 02:45
by habu2
johnwill wrote:Habu2,
If the XB-70 was to test supersonic refueling, what were they planning to use for a tanker?

The books I have didn't say, but they assumed it would be another XB-70 (KB-70?)

IMO the best XB-70 book is "Valkyrie" by Dennis Jenkins and Tony Landis, highly recommended for Valkyrie fans.

The XB-70 and the YJ93.

Unread postPosted: 03 Nov 2008, 22:20
by Kryptid
The XB-70 was capable of cruising at Mach 3. It was powered by six YJ93 turbojets, which impresses me. Unlike the SR-71, which used the unique J58 engines which combined aspects of the turbojet and the ramjet, the YJ93 was a raw turbojet.

Classically, one is told that simple turbojets do not do well at Mach 3 and can even be destroyed by such speeds. What special design implementations were there in the YJ93 that allowed it to do what other turbojets could not?

If a Mach 3 turbojet could be designed in 1960's, then why haven't we seen more Mach 3 turbojet designs in more recent years? Surely we would be able to design engines with such capabilities with even greater efficiency than the YJ93?

What are the drawbacks to Mach 3 turbojets? High costs? Long maintenance times? Poor performance at low altitudes and low airspeeds? Large size?

RE: The XB-70 and the YJ93.

Unread postPosted: 04 Nov 2008, 01:35
by Roscoe
Fuel flow sucks, and long term health due to the high temps are also lousy