OT B-2 crash video

They have security camera footage of the recent B-2 crash he
http://www.acc.af.mil/shared/media/d...080605-049.wmv
(The takeoff run occurs around halfway through the video, in the first
half another B-2 takes off successfully)
The aircraft's air data sensors were disabled by water plugging them in
the humid Guam conditions, and it attempted takeoff while traveling ten
knots too slow.
The crash could have been easily avoided; the air data sensors have
deicing heaters in them, and a previous near-mishap due to water
clogging was shown to be easily fixed by running the deicers prior to
starting the takeoff roll; unfortunately, that info never made it to all
the operational crews, so lives were endangered and a extremely costly
aircraft was lost.
As the footage shows, it does a wobbling climb at a high angle of attack
while stalling and then slams into the ground after the crew ejects,
creating one mighty big splash of burning fuel.
Although very lengthly to download, another view of the crash is shown
he http://www.acc.af.mil/shared/media/d...080605-046.mpg
This seems to show the crew tried to land the aircraft after the stall.

Pat

Pat Flannery wrote in
dakotatelephone:


Although very lengthly to download, another view of the crash is shown
he http://www.acc.af.mil/shared/media/d...080605-046.mpg
This seems to show the crew tried to land the aircraft after the stall.

Looked like they almost recovered, too. Bet there'll be a big overhaul
of flight software since that might have been frustrating their effort
to reassert control. That's kind of an issue with full fly-by-wire for
inherantly unstable aircraft; if it loses it, you lose it regardless.

Over a billion dollars, sheesh...

Meanwhile, Northrup apparently has a contract to build a stealthy
bigger bomber that may be based on the same general design. The
description seems to imply the radar cross-section is similar to an
insect's, and broad-band, too.

And they used to fly aluminum versions in the 40s and 50s without
FBW...

--Damon

On Fri, 06 Jun 2008 13:57:37 -0500, Damon Hill
wrote:

And they used to fly aluminum versions in the 40s and 50s without
FBW...

....And one of the reasons Symington is rotting in Hell. Had we gone
with the original "Flying Wing", we'd have been that much ahead on
stealth. For the want of a Convair buyout, the future was at least
postponed a quarter of a century.

OM
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] Let's face it: Sometimes you *need* [
] an obnoxious opinion in your day! [
]=====================================[

OM wrote:
On Fri, 06 Jun 2008 13:57:37 -0500, Damon Hill
wrote:

And they used to fly aluminum versions in the 40s and 50s without
FBW...

...And one of the reasons Symington is rotting in Hell. Had we gone
with the original "Flying Wing", we'd have been that much ahead on
stealth. For the want of a Convair buyout, the future was at least
postponed a quarter of a century.

All I know about the flying wings I've only learned from the discovery
channel so I could be really wrong... but...

Isn't the flying wing how Edwards AFB got its name - that the initial
plane(s) were very unforgiving in a stall and it wasn't until FBW that
one could "reliably" (this crash notwithstanding) fly such a thing?

I understand that the pilot who made the transcontinental flight which
impressed Truman wasn't terribly impressed with the plane at the time.

Also, isn't "stealth" more than just the shape? Isn't it also
materials? Wasn't the DeHaviland Mosquito a (for its time) a rather
stealthy aircraft being made of wood, but not an otherwise stealthy
shape? Spruce Goose notwithstanding, could a Flying Wing of the size
of a bomber have been made from wood at the time or did it also have
to wait for the composite materials of the current era?

rick jones
--
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these opinions are mine, all mine; HP might not want them anyway...
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On Fri, 6 Jun 2008 21:21:01 +0000 (UTC), Rick Jones
wrote:

Isn't the flying wing how Edwards AFB got its name - that the initial
plane(s) were very unforgiving in a stall and it wasn't until FBW that
one could "reliably" (this crash notwithstanding) fly such a thing?

Captain Glenn Edwards, the co-pilot, was a native of California, which
is why the base was named after him, not the pilot. The pilot was
either Forbes or Fitzgerald and there already was a base with a very
similar name.

Once again, confusion between fly-by-wire and highly-augmented flight
control systems rears its baffled head. The lack of fly-by-wire
capability wasn't the issue and it pretty much never is. Fly by wire,
fly by cable, fly by push rod and bell crank--it's all about the same,
except for battle damage reduction and weight reduction. The feedback
stability from a highly-augmented flight control system was the issue
and analog systems had their limits. You could use them on statically
unstable aircraft quite nicely, though.

Also, isn't "stealth" more than just the shape? Isn't it also
materials? Wasn't the DeHaviland Mosquito a (for its time) a rather
stealthy aircraft being made of wood, but not an otherwise stealthy
shape? Spruce Goose notwithstanding, could a Flying Wing of the size
of a bomber have been made from wood at the time or did it also have
to wait for the composite materials of the current era?

It depends. Shape is probably more important than material, but
material is, indeed, important. I mean, the SR-71 has a radar return
more like that of a C-172 than an F-4, and it's pretty much all
titanium (the other two are aluminum). Composites make it easier to
produce components with complex curves, which is what makes them
important in stealth, and they're lighter than metal components, which
makes them important in performance, but they're not magic.

Mary "It's always compromise. Always."
--
Mary Shafer Retired aerospace research engineer
We didn't just do weird stuff at Dryden, we wrote reports about it.
or
Visit my blog at http://thedigitalknitter.blogspot.com/

"Reunite Gondwanaland (Mary Shafer)" wrote:
Once again, confusion between fly-by-wire and highly-augmented
flight control systems rears its baffled head. The lack of
fly-by-wire capability wasn't the issue and it pretty much never is.
Fly by wire, fly by cable, fly by push rod and bell crank--it's all
about the same, except for battle damage reduction and weight
reduction. The feedback stability from a highly-augmented flight
control system was the issue and analog systems had their limits.
You could use them on statically unstable aircraft quite nicely,
though.

I suspect that among those of us in the peanut gallery "fly by wire"
has come to be synonymous with what I suspect those not of the peanut
gallery such as yourself call the highly-augmented flight control
system. Probably not too unlike how many use the shorthand of Kleenex
to refer to a disposable facial tissue

Perhaps even more so as we (at least I) tend to go so far as to think
of it as "Pilot says s/he wants to turn left and computer program
agrees and turns the plane left."

rick jones
loyal if oft-befuddled member of the peanut gallery
--
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where do you want to be today?
these opinions are mine, all mine; HP might not want them anyway...
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...

In article ,
Reunite Gondwanaland (Mary Shafer) wrote:

Captain Glenn Edwards, the co-pilot, was a native of California, which
is why the base was named after him, not the pilot. The pilot was
either Forbes or Fitzgerald and there already was a base with a very
similar name.

I quote Wikipedia, which happens to agree with my personal recollection:

"Forbes Air Force Base [Kansas] was named for Major Daniel Forbes,
an Air Force pilot from Kansas who was killed in a crash of the
Northrop YB-49 Flying Wing."

--
Kathy Rages
** Posted from http://www.teranews.com **

Rick Jones wrote:
Isn't the flying wing how Edwards AFB got its name - that the initial
plane(s) were very unforgiving in a stall and it wasn't until FBW that
one could "reliably" (this crash notwithstanding) fly such a thing?


I built and flew a lot of flying wing glider models; their stall
characteristics are horrible.
They're great as gliders, except for the lack of yaw stability*, but put
power on them and you are asking for trouble.
In stall, they climb straight nose-up, then backslide through the air
trailing-edge first till they end up in a nose-first dive.
Edward's YB-49 apparently did that, breaking apart as it reared up
belly-first into the airstream.
You can see a less severe version of that with the B-2 video - as the
aircraft climbs at way-too-high of a angle of attack as it leaves the
runway. A conventional design of aircraft would have lost lift and speed
way before it hit that pitch angle, and basically have gone sloshing
through the air, letting the crew pancake it back onto the runway at
worst, and letting it never completely leave the runway at best.

* They soar like gulls!
Had one get around a 20-to-1 glide ratio; (one foot drop in altitude for
every twenty feet of forward flight) ... if there'd been even mild
thermals that day it might have just vanished into the sky and ended up
somewhere in South Dakota. :-)

Pat

Damon Hill wrote:

And they used to fly aluminum versions in the 40s and 50s without
FBW...

And the lack of FBW is why we didn't keep flying them.

D.
--
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http://derekl1963.livejournal.com/

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

On Fri, 06 Jun 2008 21:40:13 GMT, (Derek Lyons)
wrote:

Damon Hill wrote:

And they used to fly aluminum versions in the 40s and 50s without
FBW...

And the lack of FBW is why we didn't keep flying them.

Fly by wire isn't that special. Pushrods and bell cranks, cables and
capstans, whatever, really only makes a huge difference for reducing
battle damage and reducing aircraft weight. The first matters in
military aircraft and the second in airliners.

Don't confuse highly-augmented flight control systems with
fly-by-wire. They're inextricably linked in many people's minds, but
they truly are entirely separate.

It wasn't the presence or absence of fly by wire that was a problem
for unstable aircraft, it was the presence or absence of
highly-augmented flight control systems. The F-16 is a nifty, gee
whiz, statically unstable aircraft that performed well because of its
analog flight control system, not its FBW system. Hydraulics would
have worked just as well.

However, flying unstable aircraft augmented with feedback control
systems wasn't that difficult. The XB-49 system wasn't perfect, but
it wasn't intended to be. If it had been, it wouldn't have had the X
in the name. Had the USAF kept going on the project, we might have
had operational flying wing bombers within a few years.

Mary "I love FBW, but it's really not that big a deal"
--
Mary Shafer Retired aerospace research engineer
We didn't just do weird stuff at Dryden, we wrote reports about it.
or
Visit my blog at http://thedigitalknitter.blogspot.com/