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PSA53
Topic Author
Posts: 2939
Joined: Tue Aug 19, 2003 1:54 pm

SST, U.S. Style

Sat Oct 25, 2003 6:57 am

There was the U-2 and the SR-71 that did supersonic.But there was a
third. The North American XB-70 or Valkyrie.This was designed as the
first supersonic transport bomber. Three of the type were built in which
the first type flew on 9/24/64. XB-70a was powered by six General
Electric,yj93-ge3, which were 19 3/4 feet long. The GE's produced
30,000 lbs thrust and on 4/12/66, went Mach 3.08.

The nose was adjustable for proper modes of flight. The aircraft
stood 30 feet high, delta wing(retractable tips) length of 105 feet.
The Valkyrie was 185 feet in lenght and two vertical stabilizers on
the delta wing and a forward canard w/ flaps just behind the cockpit.

I can account for two of the three types.
Sadly, a fighter escort on a test flight, which is unclear to me, collided
into the Valkyrie,taking off the vertical stabilizers and heavy damaged
to the delta wing, sealed it's fate.

The second,last time I heard, is at Wright-Anderson AFB, Ohio.

What happen to the third? Does anyone know? Or was it built?

But I wonder, if someone ever had thought of turning it into civilian
application. But the U.S. did have a large supersonic transport.

Your thoughts on the Valkyrie?


Tuesday's Off! Do not disturb.
 
RickB
Posts: 807
Joined: Mon May 19, 2003 3:11 am

RE: SST, U.S. Style

Sat Oct 25, 2003 7:06 am

Psa53,

The U2 was in no way supersonic im afraid !!

Also the B58 was supersonic long before the Valkyrie was even thought of and the Valkyrie was made of stainless steel - like the Mig25 Foxbat - it was too heavy - so foil thickness steel was used - not very good for survivability, too visible on radar and not entirely convincing that it would meet its range/payload requirements.

RickB

[Edited 2003-10-25 00:07:14]

[Edited 2003-10-25 00:09:54]

[Edited 2003-10-25 00:10:38]
 
PSA53
Topic Author
Posts: 2939
Joined: Tue Aug 19, 2003 1:54 pm

RE: SST, U.S. Style

Sat Oct 25, 2003 7:23 am

I apologize,the U-2 is not a supersonic transport.
I don't know spy planes and assumed it.

The sources of the Valkyrie.
Discovery Wings
Book on the Valkyrie.

That's two confirmations!

Sorry about the problem.

Tuesday's Off! Do not disturb.
 
RickB
Posts: 807
Joined: Mon May 19, 2003 3:11 am

RE: SST, U.S. Style

Sat Oct 25, 2003 7:30 am

The Valkyrie was definately supersonic - it achieved Mach3 on a number of occasions (well ship 2 did - ship number 1 had some skin seperation issues so was speed limited to mach 2 or 2.5 I seem to remember but it may of tried mach3 at some point hence the reason why they found out about the skin issues). The Valkyrie was beset with problems from the word go however so it was never certain that it would enter service. Good looking aircraft though !!

RickB
 
pilotpip
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RE: SST, U.S. Style

Sat Oct 25, 2003 7:47 am

Boeing also had a design that looked much like the concorde. Dubbed the 2707. TWA and some other airlines had orders(TWA also ordered the concorde). But Boeing decided to scrap the program due to costs. Good Call.
DMI
 
RickB
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Joined: Mon May 19, 2003 3:11 am

RE: SST, U.S. Style

Sat Oct 25, 2003 9:03 am

Pilotpip - you must of missed the bit where the US SST program cost the same amount of money as spent by the UK on Concorde - only difference is we got an aircraft to fly as opposed to a wooden mock up !! Good call? One billion dollars and no aircraft at all?

Oh - and the decision to scrap it had nothing to do with Boeing - it was congress that canned it due to spiralling costs to government.

The Boeing 2707 went through a number of iterations from its 'fanciful' original swing wing design until it looked exactly like the Lockheed design that wasn't originally chosen !!

RickB

[Edited 2003-10-25 02:05:59]
 
airways6max
Posts: 474
Joined: Sat Aug 09, 2003 6:22 am

RE: SST, U.S. Style

Sat Oct 25, 2003 9:33 am

Boeing did make an attempt at Supersonic transport with the 2707, but it didn't get very far due to rising costs and loss of government support. Supersonic travel will never really take off until someone invents a way for supersonic aircraft to break the sound barrier without creating a sonic boom. The 7E7 will be the next step in aircraft technology, with a more aerodynamic design than today's aircraft. There probably will be a Sonic aircraft, much like Boeing's Trans-Sonic Cruiser and I predict that it will begin flying around 2040 and maybe, in a hundred years, there will be super-sonic travel, in the U.S. and elsewhere.
 
RickB
Posts: 807
Joined: Mon May 19, 2003 3:11 am

RE: SST, U.S. Style

Sat Oct 25, 2003 9:38 am

Airways6max - no Boeing didn't get very far because its design was far too ambitious at the time. The design then went through a number of iterations until it became pretty much identical to the Lockheed design that lost out to the Boeing design originally. If the US Government had just selected the Lockheed design in the first place - the US could well of had a competitor to Concorde.

The US also spent a billion dollars not getting far - fortunately, just like Concorde it was tax payers money.

RickB

 
GDB
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RE: SST, U.S. Style

Sat Oct 25, 2003 10:05 am

The real killers for the 2707 was a spec way too ambitious, Mach 3, later Mach 2.7, so it would have to be made out of titanium, difficult and expensive.
The two false starts with the -100 and -200 swing wings (until it looked like the weight of all that hinge gear would mean a payload of 0%)
The tailed delta -300 was too late, 2707 went the way of much of the US space programme in 1971.
The capacity was right, yet the range probably not much better than Concordes.
Think Concorde is loud? Fancy being near a 2707 on take off, reheated turbojets nearly twice as powerful as the Olympus 593 engines!
However, Boeing had a spec from the government that was unworkable. They tried hard but they had no supersonic experience, however Boeing's airliner pedigree was thought to be more important when they were selected to build the US SST, to the surprise of many.
The 747 was developed in parallel, seen as mostly being a cargo aircraft (hence the hump) once the 2707 was in service.
So really, the 747s eventual great (and deserved) success was more luck than judgment, in the 60's at least.
The 70s with all the oil shocks and resistance to airport expansion, was another matter.
Imagine if Boeing had decided in 1966 that both the 2707 and 747 was too much to take on at once, with the 747 being dropped? (The 90% of 2707 development paid by tax $ probably ensured both programmes went ahead).
Would airlines now have a choice between MDD and Airbus?


 
AvObserver
Posts: 2605
Joined: Sat Apr 06, 2002 7:40 am

RE: SST, U.S. Style

Sat Oct 25, 2003 10:14 am

"The second,last time I heard, is at Wright-Anderson AFB, Ohio.

What happen to the third? Does anyone know? Or was it built?

But I wonder, if someone ever had thought of turning it into civilian
application. But the U.S. did have a large supersonic transport."

XB70 #1 is in the Presidential Hangar at Wright-PATTERSON (not Anderson) AFB as part of the Air Force Museum's Presidential tour. I saw it-staggeringly long, quite a bit bigger than Concorde BUT the XB-70 was NOT an SST, it was a strategic bomber prototype. It might've had potential, however, for an SST derivative, as was once proposed for the B-58 Hustler (in VIP transport form). XB70 #2 was the one that crashed. I believe I read that subassemblies for #3 were in place when the program was cancelled but it was never finished. I'm not aware from what I've read that any thought was given to a civilian version. It was obsolete as a bomber, due to its high altitude, Mach 3 only flight profile, a potential sitting duck for improving Soviet missiles and interceptors.

"The Boeing 2707 went through a number of iterations from its 'fanciful' original swing wing design until it looked exactly like the Lockheed design that wasn't originally chosen !!"

That Boeing farted around with the swing-wing for too long was probably why so much money was spent without result. It probably looked good on paper, seeming to solve the conflicting low and high-speed performance issues but when they got around to engineering it, the complexity, maintenance issues and weight doomed it. Had Lockheed's L-2000 been chosen instead, the U.S. might've had at least an SST prototype in the air although I'm sure that with the sharply higher fuel costs resulting from the first Arab oil embargo in 1973, even that would never have gone into service.
 
USAFHummer
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RE: SST, U.S. Style

Sat Oct 25, 2003 12:42 pm

The midair collision with the XB-70 involved an F-104 Starfighter, piloted by civilian test pilot Joe Walker, on a photo shoot...the F-104 flew way too close in formation with the XB-70's starboard (?) wing, and the vortices of the massive wing just sucked the F-104 right in, causing the collision...from what Ive read apparently Walker was way out of his league trying to fly that close to the XB-70 in formation...he was killed in the accident though...

Greg
Chief A.net college football stadium self-pic guru
 
wedgetail737
Posts: 5373
Joined: Mon Aug 04, 2003 8:44 am

RE: SST, U.S. Style

Sat Oct 25, 2003 12:45 pm

Aerodynamically, I think the Sonic Cruiser could do it. I don't think the engine technology is there yet.
 
FedExDC-10
Posts: 186
Joined: Tue Aug 29, 2000 7:53 am

RE: SST, U.S. Style

Sat Oct 25, 2003 12:53 pm

AvObserver is correct. The XB-70 at Wright-Pat is the only one.
 
User avatar
RayChuang
Posts: 8139
Joined: Sat Jun 24, 2000 7:43 am

RE: SST, U.S. Style

Sat Oct 25, 2003 1:57 pm

The USA may be back in the supersonic transport business sooner than people think.

Gulfstream Aerospace is working on something that may look like this:



Unlike the Concorde, the proposed Gulfstream supersonic business jet will dramatically reduce (if not completely eliminate) the problem of people hearing the sonic boom on the ground, and the jet engines will meet today's strict rules on noise and exhaust emissions. There is surprisingly strong interest in such a plane; Warren Buffet's NetJets company has expressed interest in buy a fleet of them to be operated on a fractional share basis on transatlantic flights.

 
B2707SST
Posts: 1289
Joined: Wed Apr 23, 2003 5:25 am

RE: SST, U.S. Style

Sat Oct 25, 2003 6:09 pm

No third XB-70 was planned or built. The Valkyrie was diverted from weapons system to research program on December 3, 1959, when the Eisenhower Administration cancelled the B-70 bomber. Two XB-70s were completed as high-speed, high-altitude test planes, in part to support the growing SST project. Thus on April 14, 1967, as Boeing prepared to cut metal in Seattle, SST Program Director General J. Maxwell commented that "this is the advanced aeronautical program in the United States. This is the only one."

http://www.labiker.org/xb70.html has lots of great information on the XB-70.

North American, Boeing, and Lockheed all entered the Phase I competition of the US/SST program, which required designs to be submitted in early 1964. North American's was quickly dropped, because the conflicting requirements of a military-spec'ed strategic bomber and an efficient civilian airliner are too different to bridge with one design. Oddly enough, during the Advanced Manned Strategic Aircraft program, the Air Force seriously considered using modified Boeing 2707 airframes as XB-70 replacements (I have a picture of a B2707 bomber refueling in midair from a KC-5, which also never materialized). The same objections were raised and the idea faded away, although SST purchases as light freighters, troop transports, and medevac aircraft were seen as likely. By the way, the AMSA eventually because the B-1A.

I don't think there's any doubt that Boeing underestimated the engineering challenges of an SST generally (though this was true of all four firms that tried to build one) and a swing-wing design in particular, but the Achilles' heel that initially surfaced on the 2707-100 design was stability, not weight. After moving the engines and support systems from under the 733's wing box to under the 2707's tail, Boeing found that it had to enormously increase elevator and elevon surface areas. This was to compensate for the decreased moment arm caused by the center of gravity's rearward movement. Much of the 2707-100's giant fixed tail comprised control surfaces of one sort or another.

When a final round of wind tunnel tests and computer analyses came in after Boeing won the FAA contract, it was found that extreme flight conditions (e.g. a microburst) requiring maximum upward pitch in a very short time frame could cause structural failure of the fuselage - on such a long aircraft (308 feet) the downward load on the tail induced unacceptable bending of the forward fuselage. Subsequent stiffening and addition of canards to balance pitch loading sent the 2707-200's weight spiraling upward to between 750,000 and 800,000 pounds. For inexplicable reasons, the FAA refused to allow MTOW to exceed 675,000 pounds, so as GDB mentioned, the payload was squeezed to virtually nothing. In a desperate attempt to get the weight down, Boeing had no choice but to drop the swing wing mechanism.

The final fixed double-delta 2707-300 was an extremely poor performer. In order to clear airport noise limits with the decreased lift/drag ratio of a delta vs. a variable-sweep wing at low speed, the -300's main (aft) delta was swept at only 50 degrees and was comparatively much larger than Concorde's or the L-2000's. The large area and low sweep cost it severely in supersonic cruise: the 2707-100's L/D at Mach 2.7 was 8.5; Concorde's at Mach 2 is about 7.5; and the 2707-300's would have been a paltry 7.3. Subsonic L/D also fell substantially. In order to compensate for lower L/Ds, resolve flutter problems on the lightly-loaded high-span delta, and keep the payload around 250 seats, maximum gross weight passed 800,000 pounds in early 1971 and was headed higher - far higher than the -200 but with lower performance. The 2707-300 would not have been a successful aircraft in scheduled service.

2707-100:


2707-300 (not to scale with above; the -300 was 8 feet shorter than the -100):


--B2707SST
Keynes is dead and we are living in his long run.
 
srbmod
Posts: 15446
Joined: Tue Mar 20, 2001 1:32 pm

RE: SST, U.S. Style

Sun Oct 26, 2003 12:00 am

In the mid-1990s, MDD had the HSCT in the planning stages as a 300 pax SST with a Mach 2.4 cruising speed (@ 65,000 ft).



Until the means of reducing the sonic boom are mastered, there will be no civilian supersonic aircraft developed. That is one of the reasons why the various projects by Gulfstream, Dassault, and Sukhoi has never gotten too far from the drawing board. Until someone develops an commercial a/c engine that can achieve supersonic flight without the use of afterburners (P&W does have the F119- PW-100 it developed for the F-22 Raptor which can do this), many designs will stay on paper.
 
GDB
Posts: 13995
Joined: Wed May 23, 2001 6:25 pm

RE: SST, U.S. Style

Sun Oct 26, 2003 5:35 am

Too true srbmod, matching the Olympus 593's 43% thermal efficiency at Mach 2, 50000+ feet, yet also meet the increasingly tough demands of noise, emissions and match today's airliners for fuel consumption at subsonic speeds, is a very expensive and tough call.
 
RickB
Posts: 807
Joined: Mon May 19, 2003 3:11 am

RE: SST, U.S. Style

Sun Oct 26, 2003 6:03 am

srbmod,

As GDB says - its worth remembering that the Olympus 593 also gives Concorde the ability to supercruise (i.e. no reheat is used whilst cruising at Mach 2.0) - its only taken the military nearly 40 years to catch up with civil aerospace !!

RickB

[Edited 2003-10-25 23:04:26]
 
dw747400
Posts: 1100
Joined: Wed Aug 15, 2001 8:24 am

RE: SST, U.S. Style

Sun Oct 26, 2003 12:57 pm

AvObserver is correct, flight vehicle #3 was planned and in initial construction when the program was canceled. I have a book (which incidently was bought at Wright-Pat) containing diagrams of specific changes to AV3 compared to AV1 and 2, as well as procurement listing for various components, etc. Evidently it was stored for a number of years and then sold off for scrap.

Just to add to what has already been stated... she is one impressive bird. If you ever have a chance to make it to Wright-Patterson, be sure to take the bus out to the Experimental Hangar and take a look.
CFI--Certfied Freakin Idiot
 
PSA53
Topic Author
Posts: 2939
Joined: Tue Aug 19, 2003 1:54 pm

RE: SST, U Style

Sun Oct 26, 2003 1:21 pm

Wright-Anderson AFB? Where the hell did I get that?
I back tracked last night,went into the Valkyrie book,
reviewed video tapes on Valkyrie, and I couldn't find
my or any other miscue/misprint mistakes.

As I left my store tonight,we are in sales, there was
an Anderson application. I put 2 and 2 together. Yesterday,
the Valkyrie book was on top of the application.I taking
rough notes out the book and guess what happen?

GREAT! I feel wonderful!

TEST PILOT FOR HIRE HERE! CHEAP!
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