747 cargo splits in two during takeoff!

On May 25, 10:15*pm, "Morgans" wrote:

*Google "balanced field" *and see what you find out.

A balanced field is where the accelerate go and accelererate stop
distances are equal. This produces a balanced V1. This will give you
the minimum field length for a given wieght (It can also be calculated
for an ATM or fixed derate). It does not give you the max takeoff
wieght and not all airlines use it.


From what I understand, it is a calculation done before every takeoff, and
it has to do with how far and how fast they will be able to go down the
runway, and still abort and get stopped on the runway, safely.

This would be the accelerate stop distance.

F Baum

On Sun, 25 May 2008 18:39:21 -0700 (PDT), Tina
wrote:

B, I can appreciate the 'go mode' from some speed onward, but runway
lengths vary by some thousands of yards. With a typical load and
normal conditions, how long a runway would allow you to decide to not
go if something drastic happened at just below lift off speed (like a
door blowing open, or a windscreen failing, something like that)?

all australian airfields for Airline Transport use have published
figures TORA TODA ASDA LDA

tora - takeoff runway available
toda - takeoff distance available
asda - accelerate and stop distance available
lda - landing distance available

you can find what the aircraft requires from the equivalent of the POH
and just compare the values.
(it is a tad more complex but that is basically it)
from dim memory asda assumes a stand on the brakes from V1.

Stealth Pilot

Stealth Pilot wrote in
:

On Sun, 25 May 2008 18:39:21 -0700 (PDT), Tina
wrote:

B, I can appreciate the 'go mode' from some speed onward, but runway
lengths vary by some thousands of yards. With a typical load and
normal conditions, how long a runway would allow you to decide to not
go if something drastic happened at just below lift off speed (like a
door blowing open, or a windscreen failing, something like that)?

all australian airfields for Airline Transport use have published
figures TORA TODA ASDA LDA

tora - takeoff runway available
toda - takeoff distance available
asda - accelerate and stop distance available
lda - landing distance available

you can find what the aircraft requires from the equivalent of the POH
and just compare the values.

Um, not exactly. We do have graphs, but I haven't even seen one in years.
(I know whee they are if needs be,m though)
Depending on the kind of operation and how close you get to limiting
numbers, you can either use the figures from a quick reference handbook,
often condensed into a booklet of flip cards you use for your speeds,
(common for 737 type ops where all the runways are relatively long and the
airplane usually light) or you have a set of tables, either in a big book
or on computer, which you use to calculate the max takeoff for the runway
and conditions and to give you the speeds for the takeoff in order to
gauruntee you have accelerate-stop, climb performance and obstacle
clearance as well as looking after some other odds and ends like tire
speeds and brake energy limits, all capped by max structural of course.
In addition we have a range of speeds that can be used. This is usually
done for us, but in some airplane ops combinations, its best left up to the
captain on the day to calculate. That gives us what you would call Vx or Vy
in a light aircraft or somethng in between which would give us a good
comprimise between a relatively short runway and a climb speed that would
give a decent weight allowance for the climb. It's called improved climb
performance (someone is going to pick me up on this with the more proper
definition of improved climb, but if you read that statement carefully,
you'll see it's correct)

(it is a tad more complex but that is basically it)
from dim memory asda assumes a stand on the brakes from V1.

Actually, in a lot of airplanes nowadays you must do a rolling takeoff or
you'll wreck the runway!



Bertie


Bertie

So we'll blame it on the hysterical news media not knowing of what they
write.
B

"D Ramapriya" wrote in message
...
On May 25, 7:20 pm, "BT" wrote:
Talk about a miss representation of facts..

I merely typed out the CNN headline.

snip

Ramapriya

Is the rolling start to protect the runway driven by exhaust gas
temperature effects on the runway surface? That has to be a silly
questiion, it can't be related to the airplane weight, since the take
off portion is also where they land, and they are not light on their
toes!

On May 26, 10:36 am, Bertie the Bunyip wrote:
Stealth Pilot wrote :



On Sun, 25 May 2008 18:39:21 -0700 (PDT), Tina
wrote:

B, I can appreciate the 'go mode' from some speed onward, but runway
lengths vary by some thousands of yards. With a typical load and
normal conditions, how long a runway would allow you to decide to not
go if something drastic happened at just below lift off speed (like a
door blowing open, or a windscreen failing, something like that)?

all australian airfields for Airline Transport use have published
figures TORA TODA ASDA LDA

tora - takeoff runway available
toda - takeoff distance available
asda - accelerate and stop distance available
lda - landing distance available

you can find what the aircraft requires from the equivalent of the POH
and just compare the values.

Um, not exactly. We do have graphs, but I haven't even seen one in years.
(I know whee they are if needs be,m though)
Depending on the kind of operation and how close you get to limiting
numbers, you can either use the figures from a quick reference handbook,
often condensed into a booklet of flip cards you use for your speeds,
(common for 737 type ops where all the runways are relatively long and the
airplane usually light) or you have a set of tables, either in a big book
or on computer, which you use to calculate the max takeoff for the runway
and conditions and to give you the speeds for the takeoff in order to
gauruntee you have accelerate-stop, climb performance and obstacle
clearance as well as looking after some other odds and ends like tire
speeds and brake energy limits, all capped by max structural of course.
In addition we have a range of speeds that can be used. This is usually
done for us, but in some airplane ops combinations, its best left up to the
captain on the day to calculate. That gives us what you would call Vx or Vy
in a light aircraft or somethng in between which would give us a good
comprimise between a relatively short runway and a climb speed that would
give a decent weight allowance for the climb. It's called improved climb
performance (someone is going to pick me up on this with the more proper
definition of improved climb, but if you read that statement carefully,
you'll see it's correct)

(it is a tad more complex but that is basically it)
from dim memory asda assumes a stand on the brakes from V1.

Actually, in a lot of airplanes nowadays you must do a rolling takeoff or
you'll wreck the runway!

Bertie

Bertie

Tina wrote in
:

Is the rolling start to protect the runway driven by exhaust gas
temperature effects on the runway surface? That has to be a silly
questiion, it can't be related to the airplane weight, since the take
off portion is also where they land, and they are not light on their
toes!



Yes, but we're not even supposed to do it on concrete runways which I've
never understood. I've also had instructors tell me that sucking bits of
the runway up in fornt of you is an issue which sounds pretty unlikely
to me, and alos that the torsional load on the runway is an issue, which
certainly seems possible when you see the damage braking and turning on
the runway causes, but it's not really my department, i just do as I'm
told!


Bertie

On May 26, 12:35 pm, Bertie the Bunyip wrote:
Tina wrote :

Is the rolling start to protect the runway driven by exhaust gas
temperature effects on the runway surface? That has to be a silly
questiion, it can't be related to the airplane weight, since the take
off portion is also where they land, and they are not light on their
toes!

Yes, but we're not even supposed to do it on concrete runways which I've
never understood. I've also had instructors tell me that sucking bits of
the runway up in fornt of you is an issue which sounds pretty unlikely
to me, and alos that the torsional load on the runway is an issue, which
certainly seems possible when you see the damage braking and turning on
the runway causes, but it's not really my department, i just do as I'm
told!

Bertie

Bertie, don't say things like you do as you're told in this news
group. There will be some pretty inventive "I told you to's".

Thanks for the information -- I guess FOD is a consideration, but some
FO's, like birds, insist on being blended then cooked no matter what.

Tina wrote in
:

On May 26, 12:35 pm, Bertie the Bunyip wrote:
Tina wrote
innews:35a573d0-56f5-452a-abd8-37ddd3ccc956
@l42g2000hsc.googlegroups.c
om:

Is the rolling start to protect the runway driven by exhaust gas
temperature effects on the runway surface? That has to be a silly
questiion, it can't be related to the airplane weight, since the
take off portion is also where they land, and they are not light on
their toes!

Yes, but we're not even supposed to do it on concrete runways which
I've never understood. I've also had instructors tell me that sucking
bits of the runway up in fornt of you is an issue which sounds pretty
unlikely to me, and alos that the torsional load on the runway is an
issue, which certainly seems possible when you see the damage braking
and turning on the runway causes, but it's not really my department,
i just do as I'm told!

Bertie

Bertie, don't say things like you do as you're told in this news
group. There will be some pretty inventive "I told you to's".


Well, this one is in the flight manual, so it's what we do.

Thanks for the information -- I guess FOD is a consideration, but some
FO's, like birds, insist on being blended then cooked no matter what.

Well, it's not a big deal for little ones anyway. I have done full power
on the brakes in things like 737s, but it's definitely not allowed in
the A300 I used to fly and we don't do it in the 75 or 76 either.


Bertie

On May 26, 10:48*am, Bertie the Bunyip wrote:


Yes, but we're not even supposed to do it on concrete runways which
I've never understood. I've also had instructors tell me that sucking
bits of the runway up in fornt of you is an issue which sounds pretty
unlikely to me, and alos that the torsional load on the runway is an
issue, which certainly seems possible when you see the damage braking
and turning on the runway causes, but it's not really my department,
i just do as I'm told!

Bertie

Thanks for the information -- I guess FOD is a consideration, but some
FO's, like birds, insist on being blended then cooked no matter what.

Well, it's not a big deal for little ones anyway. I have done full power
on the brakes in things like 737s, but it's definitely not allowed in
the A300 I used to fly and we don't do it in the 75 or 76 either.

Aside from the FOD the book also mentions Stall/Surge if you have an
Xwind or Twind. This makes sense to me. The added TO distance is
negligable anyways. Even for a static TO we only stand em up and then
release the brakes and punch TOGA. Im like you man, they sign my check
and if thats the ways they want it done,,,,,,,,,,,,,

F Baum

"F. Baum" wrote in news:cf3bac99-86ae-41c2-976d-
:

On May 26, 10:48*am, Bertie the Bunyip wrote:


Yes, but we're not even supposed to do it on concrete runways
which
I've never understood. I've also had instructors tell me that
sucking
bits of the runway up in fornt of you is an issue which sounds
pretty
unlikely to me, and alos that the torsional load on the runway is
an
issue, which certainly seems possible when you see the damage
braking
and turning on the runway causes, but it's not really my
department,
i just do as I'm told!

Bertie

Thanks for the information -- I guess FOD is a consideration, but
some
FO's, like birds, insist on being blended then cooked no matter
what.

Well, it's not a big deal for little ones anyway. I have done full
power
on the brakes in things like 737s, but it's definitely not allowed in
the A300 I used to fly and we don't do it in the 75 or 76 either.

Aside from the FOD the book also mentions Stall/Surge if you have an
Xwind or Twind. This makes sense to me. The added TO distance is
negligable anyways. Even for a static TO we only stand em up and then
release the brakes and punch TOGA. Im like you man, they sign my check
and if thats the ways they want it done,,,,,,,,,,,,,


Yeah, that too. Though I've never had one in a high baypass engine.
Plenty with JT8s, of course.. Almost normal with them especially in the
727. I'd have to look it up in the 75/76 manuals, but you know what
they're like these days. they tell you what to do but seldom why
anymore...


Bertie