"Priceless" in Afghanistan

BUFDRVR wrote:

Doesn't that thing do over the shoulder nuke deliveries? Pull up, throw
nukeout, continue over the top, 1/2 cuban 8 type thing, accel and run like
hell???I'll bet it does...

It was designed to do "lay down" nuclear bomb runs, not loft. I've seen them do
some pretty agressive (for a big plane) pitch outs, but I'm not sure if they
could execute an immelman or not.

Don't see why not. If the high-altitude designed B-47s could do them (admittedly,
with some serious wing fatigue problems as a result), then the low-altitude
stressed B-1 shouldn't mind.

Guy

Don't see why not. If the high-altitude designed B-47s could do them
(admittedly,
with some serious wing fatigue problems as a result), then the low-altitude
stressed B-1 shouldn't mind.

It's not a stress issue, it's an excess thrust issue. The Bone may be able to
pull off an immelman,but I'm betting you won't find too many pilots eager to
test out that theory.

By the way, the B-47 could do many things niether the B-52 or B-1B can do.


BUFDRVR

"Stay on the bomb run boys, I'm gonna get those bomb doors open if it harelips
everyone on Bear Creek"

In article ,
(BUFDRVR) writes:
Don't see why not. If the high-altitude designed B-47s could do them
(admittedly,
with some serious wing fatigue problems as a result), then the low-altitude
stressed B-1 shouldn't mind.

It's not a stress issue, it's an excess thrust issue. The Bone may be able to
pull off an immelman,but I'm betting you won't find too many pilots eager to
test out that theory.

If it's qn excess thrust issue, than that would weight it even further
into the "Yes, sure the B-1 can do an Immelman" side. Of all the
things the B-47 didn't have, thrust was probably the most obvious.
According the the B-47S Standard Aircraft Characteristics, Takeoff
Ground Roll for a loaded B-47E-IV, without RATO, could be upwards of
10.500'. That's not exactly a high t/w. (A better context for excess
thrust numbers woudl be SEP at Combat Weight - in that case, the B-47E
data gives us 4450 '/mion @ Sea Level, a 1965-era B-52H gives
6500'/minute. (Score one for the Buff)

For that matter, I've flown planty of Immelmans in sailplanes - it's
hard to find a lower T/W than 0. (Although the roll at the top _was_
kinda sloppy_ What would be more important is Drag/Weight. If you'ge
got a really slippery shape, you won't lose speed as quickly with the
nose high.
If thrust exactly equalled drag (SEP = 0), it'd take _anything_ pulled
straight up anout 260 seconds to lose 300 KTS. Your entry adn exi t
speeds would be rather dependant on the airplane, of course. but
there's plenty of energy for a 2-3 G pull through 180 degrees.


By the way, the B-47 could do many things niether the B-52 or B-1B can do.

Well, fly around the pattern trailing a parachute is one...
Tobogganing behind an overstressed KC-97 would be another.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

If it's qn excess thrust issue, than that would weight it even further
into the "Yes, sure the B-1 can do an Immelman" side. Of all the
things the B-47 didn't have, thrust

Remember, the B-47 did their immelmans from high altitude (and entered from a
dive obviously), the Afghanistan Bone would be entering from straight and
level, thus it becomes an excess thrust issue.

Well, fly around the pattern trailing a parachute is one...
Tobogganing behind an overstressed KC-97 would be another.


Cruising around, fully loaded (albeit a smaller load than a BUFF or Bone) at
40K+ and .90 mach. Doing an immelman at high altitude (not possible for a
BUFF...maybe for a Bone, but not from 30K+).




BUFDRVR

"Stay on the bomb run boys, I'm gonna get those bomb doors open if it harelips
everyone on Bear Creek"

In article ,
(BUFDRVR) writes:
If it's qn excess thrust issue, than that would weight it even further
into the "Yes, sure the B-1 can do an Immelman" side. Of all the
things the B-47 didn't have, thrust

Remember, the B-47 did their immelmans from high altitude (and entered from a
dive obviously), the Afghanistan Bone would be entering from straight and
level, thus it becomes an excess thrust issue.

Are you sure about that? Remember, the wing loading's a lot higher
than that of the B-52. Not a whole lot of excess G at altitude.
They did use Immelmans as an escape maneuver when they decided tht low
level was the way to go, and that the best way to do that was with a
LABS delivery. It didn't last long though, In the first 3 months that
they tried it in the field, they lost 3 airplanes due to structural
failure. They modified their technique to a low-level ingress with a
pop up to about 10-12,000' to drop a drogued weapon, and a diving turn
away immediately after weapon release.


Well, fly around the pattern trailing a parachute is one...
Tobogganing behind an overstressed KC-97 would be another.


Cruising around, fully loaded (albeit a smaller load than a BUFF or Bone) at
40K+ and .90 mach. Doing an immelman at high altitude (not possible for a
BUFF...maybe for a Bone, but not from 30K+).


Well, I'll admit I'm a little on the young side to have flown a
B-47. (But I was at Pease when the last one in service was flown in
to be a gate guard - U.S. Navy markings, and a North American
Autonetics crew. That was 76 or 77 or so) But I've known plenty of
peolple who have. For a loaded B-47, 40 Kft was about all you'd get.
Placard Limits are 425 KIAS up to Mach 0.86, meeting at 'bout 17.500'
I could run a o.86 at 36,000 (tropopause), but that was about it.
The 425 KIAS limit was pretty definite. Aince the wings were so
flexible, the ailerons would twist the wings, reducing, and eventually
reversing roll control. 425 KIAS was the point where you didn't have
any roll control.


--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

BUFDRVR wrote:

If it's qn excess thrust issue, than that would weight it even further
into the "Yes, sure the B-1 can do an Immelman" side. Of all the
things the B-47 didn't have, thrust

Remember, the B-47 did their immelmans from high altitude (and entered from a
dive obviously), the Afghanistan Bone would be entering from straight and
level, thus it becomes an excess thrust issue.

See below.

Well, fly around the pattern trailing a parachute is one...
Tobogganing behind an overstressed KC-97 would be another.


Cruising around, fully loaded (albeit a smaller load than a BUFF or Bone) at
40K+ and .90 mach.

Nope. B-47E SAC: Max. Spd, 606 mph (M0.84) @ 16,300 ft.; 557 mph (M0.842) @
38,550 ft.; Max. cr. spd., 495 mph (M0.75) @ 38,550 ft.; Svc. Ceiling 40,500 ft.

Doing an immelman at high altitude (not possible for a
BUFF...maybe for a Bone, but not from 30K+).

The Immelmanns were done from the deck while making LABS tosses, starting in
1957. They went down there for the same reasons the B-52s did: defenses had
driven them from high altitude to low. There were 6 B-47 crashes in the spring of
1958 brought on by fatigue failures due to these and pop-up maneuvers, which is
why Project Milk Bottle was instituted, to replace the wing milk bottle connecting
pin.

Guy

Guy Alcala wrote in message ...
BUFDRVR wrote:
SNIP
Some of the B47 wing failures were due to high speed low altitude
flying in turbulence. 420 KIAS down around Avon Park Range (FL) in the
summer can get real bumpy. As I remember McCoy AFB (Orlando Intl now)
got its name from a SAC brigadier who bought it, along with his crew,
as his B47 lost a wing in a LABS maneuver.
FWIW if the Bone engines are anything like the J79 at 700 KIAS they're
putting out maybe 25% more thrust than under static conditions. I have
seen the J79's fuel flow rise from about 8500 pph static to over 12000
pph going from 0 KIAS (brakes locked) to 600 KIAS at 500 feet off the
end of the runway. Even so, with the kinetic energy of 700 KIAS that
elephant should be able to leap tall buildings.
Walt BJ

Cruising around, fully loaded (albeit a smaller load than a BUFF or Bone)
at
40K+ and .90 mach.

Nope. B-47E SAC: Max. Spd, 606 mph (M0.84) @ 16,300 ft.; 557 mph (M0.842) @
38,550 ft.; Max. cr. spd

Hmmm, I stand corrected, I thought the -47 was faster than a BUFF at
altitude...apparently not.

The Immelmanns were done from the deck while making LABS tosses, starting in
1957.

Well, I've seen a picture (I'll try to find it) of a B-47 nearly inverted and
while exact altitude is difficult to determine, there's no visable terrain in
the shot....which has always left me the impression they were at least 20K.


BUFDRVR

"Stay on the bomb run boys, I'm gonna get those bomb doors open if it harelips
everyone on Bear Creek"

In article ,
(BUFDRVR) writes:
Cruising around, fully loaded (albeit a smaller load than a BUFF or Bone)
at
40K+ and .90 mach.

Nope. B-47E SAC: Max. Spd, 606 mph (M0.84) @ 16,300 ft.; 557 mph (M0.842) @
38,550 ft.; Max. cr. spd

Hmmm, I stand corrected, I thought the -47 was faster than a BUFF at
altitude...apparently not.

One of the things they learned with teh B-47 was that there is, indeed
such a thing as too high a wing loading for efficient cruising. At
36,000', a B-47 would efficiently cruise at arounf 435 KTAS, or about
235 KIAS. Not too bad, but the airplane stalled at arounfd 165 KIAS,
so the Induced Drag was still a pretty serious factor. (B-47 Wing
Loadings were arounf 150 lbs/ft^2) Even the H model B-52s don't come
close to that.


The Immelmanns were done from the deck while making LABS tosses, starting in
1957.

Well, I've seen a picture (I'll try to find it) of a B-47 nearly inverted and
while exact altitude is difficult to determine, there's no visable terrain in
the shot....which has always left me the impression they were at least 20K.

Hmm. It could be that they were topping out that high. IIRC, when
they were doing the LABS drops, they were entering the pullup at aound
420 KIAS, and pulling up at 2 - 2 1/2 Gs. It's still impressive,
nonetheless.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster