Take off roll
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<You do occasionally see them some 20 miles from the airport still under full power and very low.>
We're talking about something different- climbout now! PIA will be heavily loaded in an older 747. Being low is not dangerous! The performance will all have been calculated, and if evidently dangerous, you can be assured ATC will pick up on it. But we're seeing an innocent airline accused of something serious here and such unfounded accusations should not continue. I've taken off from Dharan in a fully loaded old 747 with original early model engines (-3A) in high desert temperatures (the much 'loved' G-PZ). Nosing down at 1500' in a temperature inversion to accelerate for flap retraction (and drag reduction), it wouldn't speed up. We blasted across a large part of eastern Saudi trying to get going with incredibly gradual acceleration. Not a problem. Should you lose an engine, there is an on-the-ball F/E and fuel jettison system. Over the English countryside, even in such a low powered early model, it is all allowed for in the performance. But 'very low 20 miles out'? I don't think so. More ATC than anything else.
We're talking about something different- climbout now! PIA will be heavily loaded in an older 747. Being low is not dangerous! The performance will all have been calculated, and if evidently dangerous, you can be assured ATC will pick up on it. But we're seeing an innocent airline accused of something serious here and such unfounded accusations should not continue. I've taken off from Dharan in a fully loaded old 747 with original early model engines (-3A) in high desert temperatures (the much 'loved' G-PZ). Nosing down at 1500' in a temperature inversion to accelerate for flap retraction (and drag reduction), it wouldn't speed up. We blasted across a large part of eastern Saudi trying to get going with incredibly gradual acceleration. Not a problem. Should you lose an engine, there is an on-the-ball F/E and fuel jettison system. Over the English countryside, even in such a low powered early model, it is all allowed for in the performance. But 'very low 20 miles out'? I don't think so. More ATC than anything else.
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Lots of factors can affect the takeoff roll and climbout... but just because it is performance limiting, doesn't mean it's dangerous.
It's simply not possible to takeoff at max weight out of jo'burg... and even with a reduced weight, and no thrust derate, the takeoff roll can be 4000m!!
Lancer
It's simply not possible to takeoff at max weight out of jo'burg... and even with a reduced weight, and no thrust derate, the takeoff roll can be 4000m!!
Lancer
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I took the liberty calculating classic B747 takeoff weights for Manchester, also ran a couple of Jeppesen CFPs to Pakistan. @30C the -300 is performance limited below the structural weight. If these flights are full they will be right on the limits.
Notso Fantastic, i guess that you were lucky that the VSI was on the positive side.... we have had flights out of that part of the desert recording a descent after takeoff, with 4 engines running!
Mutt.
Notso Fantastic, i guess that you were lucky that the VSI was on the positive side.... we have had flights out of that part of the desert recording a descent after takeoff, with 4 engines running!
Mutt.
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tcr2
There could be a number of reasons for the apparent difference between BA & SIA744 take-off rolls at LHR.
Some have been stated in previous posts. Others include:
i) different routes
ii) different levels of take-off derate/reduced thrust
iii) optimum vs fixed flaps. I believe that some airlines operate optimum flaps where others tend to use a single flap setting (for simplicity) at the expense of a longer take-off roll (or less derate)
iv) Possibly improved climb or not
On the PIA subject you may fancy a look at the attached link (remembering there are also many pictures on this website showing many other PIA take-offs from MAN that look fine)
http://www.airliners.net/open.file?i...tic=yes&size=L
There could be a number of reasons for the apparent difference between BA & SIA744 take-off rolls at LHR.
Some have been stated in previous posts. Others include:
i) different routes
ii) different levels of take-off derate/reduced thrust
iii) optimum vs fixed flaps. I believe that some airlines operate optimum flaps where others tend to use a single flap setting (for simplicity) at the expense of a longer take-off roll (or less derate)
iv) Possibly improved climb or not
On the PIA subject you may fancy a look at the attached link (remembering there are also many pictures on this website showing many other PIA take-offs from MAN that look fine)
http://www.airliners.net/open.file?i...tic=yes&size=L
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Hi,
*Lancer*, I know exactly what you mean. I have experienced the take-off from JNB. I was on a KLM 747-400 at JNB, the take-off was 1 minute 30 seconds
, I was timing it 
. The climb was very shallow until we got to around 10.000 feet.
BAe 146-100
*Lancer*, I know exactly what you mean. I have experienced the take-off from JNB. I was on a KLM 747-400 at JNB, the take-off was 1 minute 30 seconds
, I was timing it . The climb was very shallow until we got to around 10.000 feet.BAe 146-100
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That photo.... telephoto lens......looking down the runway.......the runway end could be 1/2mile from the aeroplane but it looks right over it! On a limiting runway, you may only be able to cross the runway end at about 30'. With engine fail at V1, it comes down a bit. Can't remember the figures. After over 2 miles of thundering down Nairobi at full power in a Classic, we only used to cross the end of the concrete at about 50' on the radio altimeter. It's all there in the performance calculations, and they are right as opposed to human judgement. Calling V1 at Bombay on a really heavy/hot T/O, I was amazed how little runway was left, and reported that I didn't believe the performance was correct. The BA Performance Section wrote to me showing it was right and we could have stopped in the space available. I didn't believe it. The week after I got their response, another 747 of ours, with one reverser locked out, same circumstances, lost another engine and abandoned at V1. Heavy/hot/2 reversers only, and stopped with 100 yards to spare.
Paxing All Over The World
146 - You are correct about JNB! More than once, I have heard the flight deck warn of the length of take off roll. Then pax do not get so concerned when they have been trundling for one minute ... the terminal buildings have all passed by ... the outer apron has gone by ... and (Yawn) the cargo terminal has gone by ... and then you can see the main Pretoria Highway ... 
The climb out over Pretoria and away to the North is usually very slow on any of the carriers. This is also why the European flights all leave before 10:00 or after 18:00, in the middle of the day, they would have to run on from 03L and use the Pretoria highway as well.
The climb out over Pretoria and away to the North is usually very slow on any of the carriers. This is also why the European flights all leave before 10:00 or after 18:00, in the middle of the day, they would have to run on from 03L and use the Pretoria highway as well.
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Paxboy
I think you'll find the departure times ex-JNB are more to do with arrival times at destination rather than anything else. The typical flight time is 10hours to N Europe, so leaving at 1000 gives arrival at 2000 and at 2000 gives 0600, much in between is not verypopular. Yes, JNB is high, sometimes hot, but usually you derate thrust quite a bit - midday 35deg C take-offs would be feasible.
I think you'll find the departure times ex-JNB are more to do with arrival times at destination rather than anything else. The typical flight time is 10hours to N Europe, so leaving at 1000 gives arrival at 2000 and at 2000 gives 0600, much in between is not verypopular. Yes, JNB is high, sometimes hot, but usually you derate thrust quite a bit - midday 35deg C take-offs would be feasible.
Paxing All Over The World
TopBunk: Thanks for correcting other information that I had received.
I am aware that the main carriers run overnight largely because of the Biz pax that are paying for the flight. Other carriers arrive overnight, turn and go or vice versa.
The problem this gives BA + VS is that their machines are on the ground for 12 hours. SA have the same problem in London. Happily, they can pass on the cost of this lousy utilisation to us.
With CPT, VS consider it a tourist run only and arrive in the early morning and turn immediately. BA stays until the evening.
I am aware that the main carriers run overnight largely because of the Biz pax that are paying for the flight. Other carriers arrive overnight, turn and go or vice versa.
The problem this gives BA + VS is that their machines are on the ground for 12 hours. SA have the same problem in London. Happily, they can pass on the cost of this lousy utilisation to us.
With CPT, VS consider it a tourist run only and arrive in the early morning and turn immediately. BA stays until the evening.
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I am ATPL student and dispatcher at a London airport. During the scorching hot period we had recently I was lucky enough to be working when the 37 deg record was broken.
I was dispatching a 737-400 with full load of pax (167Y) to Greece. I think weight of baggage was about 2000kg, fuel about 14,000kg. At the time OAT was 34 deg. When I collected flight docs and loadsheet from Flight Deck they were setting up the FMC. Noticed in the FMC the OAT was inserted as 34 deg celcius, assumed temp 38 deg celcius. So I guess they must have been pretty close to being performance limited, despite us having a 10,000ft runway.
Any 737-400 drivers able to comment?
I was dispatching a 737-400 with full load of pax (167Y) to Greece. I think weight of baggage was about 2000kg, fuel about 14,000kg. At the time OAT was 34 deg. When I collected flight docs and loadsheet from Flight Deck they were setting up the FMC. Noticed in the FMC the OAT was inserted as 34 deg celcius, assumed temp 38 deg celcius. So I guess they must have been pretty close to being performance limited, despite us having a 10,000ft runway.
Any 737-400 drivers able to comment?
