Mach 2, 60,000 foot B-1R

From this week's AvWeek. Boeing responded to an Air Force RFI against a
requirement for improved bombers by suggesting re-engining the B-1 fleet
with F-119 engines with the following characteristics: Mach 2 cruise, 3000
mile radius, 60,000 foot ceiling (with a couple of hours loiter).

Is this plausible? From others in this group, I though the B-1 was marginal
above 30,000 feet.

On Tue, 1 Jun 2004 19:50:12 -0400, "Paul F Austin"
wrote:

From this week's AvWeek. Boeing responded to an Air Force RFI against a
requirement for improved bombers by suggesting re-engining the B-1 fleet
with F-119 engines with the following characteristics: Mach 2 cruise, 3000
mile radius, 60,000 foot ceiling (with a couple of hours loiter).

Is this plausible? From others in this group, I though the B-1 was marginal
above 30,000 feet.


1. Different engines.

2. I think the Mach 2 figure was dash speed. I don't recall it
saying it could cruise that fast. One thing I was wondering is the
B-1 lost Mach 2 capability when they changed the inlets. Are they
going to change them again?

3. The B-1A could do Mach 2.2 at 60,000ft so the basic airframe is
capable of it. Comes down to the engines, intakes, weight. The
article raised more questions than it answered.


I also thought the aritcle talking about the F-22 chasing down Mach
0.6 cruise missiles a particularly desperate move. If they want to
sell the F-22s capabilities why don't they mention how it will enable
the US to maintain air supremacy over any battlefield anywhere? For
one thing if you're against an opponent you'd use F-22's against
they're not likley to be using Mach 0.6 cruise missiles. And if the
missiles are supersonic or the ballistic variety their scenario pretty
much falls apart. Why don't they mention the deterent value a
squadron or two of F-22's deployed to Taiwan in a crises would be? Oh
wait, that's not PC. The areas where the F-22 will really shine are
those where the F-15 might have a difficult time and that's against a
country with relatively large numbers of modern, high performance
aircraft. And that means China, India and East Asia in general. For
those who scoff at the idea of China ever being a threat you need to
take off the blinders. The whole China / Taiwan thing is going to
come to a head eventually and if we plan to stick to our word (fat
chance these days) then we had better be prepared.

The F119 engines make sufficient thrust to allow high altitude supersonic
cruise at a Mach somewhat less than Mach 2 while not requiring any
significant change to the current fixed inlets. The tradeoff is a
significant reduction in range.
Scott Ferrin wrote in message
...
On Tue, 1 Jun 2004 19:50:12 -0400, "Paul F Austin"
wrote:

From this week's AvWeek. Boeing responded to an Air Force RFI against a
requirement for improved bombers by suggesting re-engining the B-1 fleet
with F-119 engines with the following characteristics: Mach 2 cruise,
3000
mile radius, 60,000 foot ceiling (with a couple of hours loiter).

Is this plausible? From others in this group, I though the B-1 was
marginal
above 30,000 feet.


1. Different engines.

2. I think the Mach 2 figure was dash speed. I don't recall it
saying it could cruise that fast. One thing I was wondering is the
B-1 lost Mach 2 capability when they changed the inlets. Are they
going to change them again?

3. The B-1A could do Mach 2.2 at 60,000ft so the basic airframe is
capable of it. Comes down to the engines, intakes, weight. The
article raised more questions than it answered.


I also thought the aritcle talking about the F-22 chasing down Mach
0.6 cruise missiles a particularly desperate move. If they want to
sell the F-22s capabilities why don't they mention how it will enable
the US to maintain air supremacy over any battlefield anywhere? For
one thing if you're against an opponent you'd use F-22's against
they're not likley to be using Mach 0.6 cruise missiles. And if the
missiles are supersonic or the ballistic variety their scenario pretty
much falls apart. Why don't they mention the deterent value a
squadron or two of F-22's deployed to Taiwan in a crises would be? Oh
wait, that's not PC. The areas where the F-22 will really shine are
those where the F-15 might have a difficult time and that's against a
country with relatively large numbers of modern, high performance
aircraft. And that means China, India and East Asia in general. For
those who scoff at the idea of China ever being a threat you need to
take off the blinders. The whole China / Taiwan thing is going to
come to a head eventually and if we plan to stick to our word (fat
chance these days) then we had better be prepared.

On Wed, 2 Jun 2004 13:42:25 GMT, "breyfogle"
wrote:

The F119 engines make sufficient thrust to allow high altitude supersonic
cruise at a Mach somewhat less than Mach 2 while not requiring any
significant change to the current fixed inlets. The tradeoff is a
significant reduction in range.

I thought the requirement for adjustable inlets was to avoid the
supersonic shockwave impinging on the compressor and stalling the
engine. If so, then the thrust of the F-119 isn't oging to help at
all.

Peter Kemp

The F-101 produces enough thrust for Mach 1.2 to 1.25 and the shock is
stable somewhere in the inlet ducting. The F-119 should produce enough
extra thrust to increase the max Mach significantly. Sure, the shock front
moves aft as Mach increases and at some point the shock will reach the fan
and bad things happen. F-16's & F-18's reach 1.6 (1.8?) Mach with fixed
inlets.

"Peter Kemp" wrote in message
news
On Wed, 2 Jun 2004 13:42:25 GMT, "breyfogle"
wrote:

The F119 engines make sufficient thrust to allow high altitude supersonic
cruise at a Mach somewhat less than Mach 2 while not requiring any
significant change to the current fixed inlets. The tradeoff is a
significant reduction in range.

I thought the requirement for adjustable inlets was to avoid the
supersonic shockwave impinging on the compressor and stalling the
engine. If so, then the thrust of the F-119 isn't oging to help at
all.

Peter Kemp

On Wed, 2 Jun 2004 21:23:08 GMT, "breyfogle"
wrote:

The F-101 produces enough thrust for Mach 1.2 to 1.25 and the shock is
stable somewhere in the inlet ducting.

It sounds like you're missing the point. The F101 has enough power to
take the B-1 to Mach 2.2 and had done so prior to the inlet redesign.
Since the inlet redesign it can't go there anymore. Period. More
thrust isn't going to get you a higher top speed. More thrust
(particularly dry thrust) will get you more speed for a given weight
but if the inlets weren't an issue they'd have been fixed from the
start or else a clean B-1B would still be able to hit Mach 2+. It
can't.



The F-119 should produce enough
extra thrust to increase the max Mach significantly.

If you are comparing dry thrust to dry thrust then sure.



Sure, the shock front
moves aft as Mach increases and at some point the shock will reach the fan
and bad things happen. F-16's & F-18's reach 1.6 (1.8?) Mach with fixed
inlets.

The B-1's speed is limited by the inlets, not the engines. True, the
F119 is optimized for higher speed than the F101 but the inlets will
still make a difference.







"Peter Kemp" wrote in message
news
On Wed, 2 Jun 2004 13:42:25 GMT, "breyfogle"
wrote:

The F119 engines make sufficient thrust to allow high altitude supersonic
cruise at a Mach somewhat less than Mach 2 while not requiring any
significant change to the current fixed inlets. The tradeoff is a
significant reduction in range.

I thought the requirement for adjustable inlets was to avoid the
supersonic shockwave impinging on the compressor and stalling the
engine. If so, then the thrust of the F-119 isn't oging to help at
all.

Peter Kemp

FWIW ISTR the Mne on the F102A was M 1.5 because of its simple
intakes. Again FWIW the only way you could fet anywhere near 1.5 was
in a dive . . .1.3 level was attainable, though.
Walt BJ

breyfogle wrote:

The F-101 produces enough thrust for Mach 1.2 to 1.25 and the shock is
stable somewhere in the inlet ducting. The F-119 should produce enough
extra thrust to increase the max Mach significantly. Sure, the shock front
moves aft as Mach increases and at some point the shock will reach the fan
and bad things happen. F-16's & F-18's reach 1.6 (1.8?) Mach with fixed
inlets.

Know some pilots who swear they've gone 1.4, but only for very short
times. The biggest limiting factor are those two big RCS vanes in each
inlet.

Michael Kelly
Bone Maintainer

Why bother converting a B-1 into a supersonic reconnaissance plane,when
they could reactivate the SR-71's? What advantage would there be?

--
Jim Yanik
jyanik-at-kua.net

"Jim Yanik" wrote in


Why bother converting a B-1 into a supersonic reconnaissance plane,when
they could reactivate the SR-71's? What advantage would there be?

"R" is apparently from "Rengine" not "Reconnaissance". The article describes
responses to an Air Force RFI for improved bombers.