Bad one this AM... :(

NW_PILOT opined

"Capt.Doug" wrote in message
...
"Dave" wrote in message -
Apparently rotated, drug the tail all the way to -and hit the
ILS antenna berm. Tail separated at that impact and the rest we
know..

Don't know much about a 747, but I have watched a video produced by Boeing
that shows the effects of dragging the tail. It adds a significant amount
to
the take-off distance.

D.




Time for boeing to add a tail wheel to the 747

And delete that nose wheel.


-ash
Cthulhu for President!
Why vote for a lesser evil?

"Ash Wyllie" wrote in message And delete that nose wheel.

That would create a pilot shortage. Few of my colleagues have a tailwheel
endorsement.

D.

(John Pelchat) writes:

And as another poster noted, this was not a normal takeoff in that the
crew apparently over-rotated the airplane, resulting in the tailstrike
and diminishing the plan's performance.

It will interesting to learn more about this as the investigation
develops.

Agreed...but a tail strike by itself should not lead to a crash unless
the vertical force of contact was so extreme that it caused structural
damage. (Of course, at that angle of attack you're not going to get
your maximum Cl, so if the takeoff parameters were marginal to begin
with things could get interesting in a hurry.)

A friend of mine was one of the design engineers for the 747; he
has a film of some of the certification test flights -- including
abused takeoffs where intentional overrotation caused the tail to
contact the runway surface...and at gross weight (IIRC) it successfully
completed the takeoff.

Of course, that was a new bird without who-knows-how-many years of
service behind it.

Has there been any information available concerning loading (takeoff
weight and CG) being out of limits? An aft CG, perhaps from poorly
secured cargo that moved during takeoff and rotation, could explain
the over-rotation.

Joe Morris

A "local" update...

The voice recorder is toast (literally)

The data recorder has a broken tape, repaired, and is being
examined now...

Apparently the crew were very expirenced, and they are
wondering about the tail strike, which was not a "bump" ,- the scrape
trail was very lengthy. The shower of sparks was extensive, lasting a
long time & distance. Current speculation surrounds cargo shift aft,
holding the tail on the rny..

Extreme, but that is being checked out..

Many are wondering why an experiencd crew would hold the
tail hard on the rny knowing it would extend the TO run...

Credible eyewitnesses said all appeared normal until rotation,
and shortly after the trail of sparks started and lasted until it
"barely " lifted in ground effect until the tail hit the ILS antenna
berm.

The rest was a tumbling fireball...

Dave

On Wed, 20 Oct 2004 14:31:01 +0000 (UTC), Joe Morris
wrote:

(John Pelchat) writes:

And as another poster noted, this was not a normal takeoff in that the
crew apparently over-rotated the airplane, resulting in the tailstrike
and diminishing the plan's performance.

It will interesting to learn more about this as the investigation
develops.

Agreed...but a tail strike by itself should not lead to a crash unless
the vertical force of contact was so extreme that it caused structural
damage. (Of course, at that angle of attack you're not going to get
your maximum Cl, so if the takeoff parameters were marginal to begin
with things could get interesting in a hurry.)

A friend of mine was one of the design engineers for the 747; he
has a film of some of the certification test flights -- including
abused takeoffs where intentional overrotation caused the tail to
contact the runway surface...and at gross weight (IIRC) it successfully
completed the takeoff.

Of course, that was a new bird without who-knows-how-many years of
service behind it.

Has there been any information available concerning loading (takeoff
weight and CG) being out of limits? An aft CG, perhaps from poorly
secured cargo that moved during takeoff and rotation, could explain
the over-rotation.

Joe Morris

On Wed, 20 Oct 2004 at 14:31:01 in message
, Joe Morris
wrote:

A friend of mine was one of the design engineers for the 747; he
has a film of some of the certification test flights -- including
abused takeoffs where intentional overrotation caused the tail to
contact the runway surface...and at gross weight (IIRC) it successfully
completed the takeoff.

I think you will find that is a standard test to check the 'Velocity
Minimum Unstick' speed. A large block of wood (Usually Oak) is fastened
to the tail bumper to protect the airframe. It is not abuse but a
careful test at the Maximum practical rotation. Unless the tail has been
definitely touching for about the last 500 ft of the ground run the
test is not accurate.

For a description of this test see "21st Century Jet" by Karl Sabbach
regarding the Boeing 777.
--
David CL Francis

"Nathan Young" wrote in message

with 6000 feet of runway left, fully loaded with fuel and cargo for a
flight
from Halifax to Spain. Can the 747 really do that?

No. Not at gross.

News today on the data box...

I "heard" rotation occoured at 50 mph less than rotation
speed..

....more when I get more...

Dave


On Sat, 23 Oct 2004 11:04:01 -0400, "John Gaquin"
wrote:


"Nathan Young" wrote in message

with 6000 feet of runway left, fully loaded with fuel and cargo for a
flight
from Halifax to Spain. Can the 747 really do that?

No. Not at gross.

Here is a very cool photo of this test being done on an Airbus. They
forgot the block of wood

http://www.airliners.net/open.file?i...c=y es&size=M
Sorry about the huge URL- I don't know how to make them small.

In article . com,
wrote:
Here is a very cool photo of this test being done on an Airbus. They
forgot the block of wood

Sorry about the huge URL- I don't know how to make them small.

Neat picture.

You can cut the airliners.net url down to this:

http://www.airliners.net/open.file?id=219906

For other URLs use http://makeashorterlink.com, http://tinyurl.com
or my favorite, http://evilurl.com.

John
--
John Clear - http://www.panix.com/~jac

wrote in message ups.com...
Here is a very cool photo of this test being done on an Airbus. They
forgot the block of wood

If you blow up the picture, it looks like a large red block of something
(probably oak) is doing exactly what it s'possed to do.