Take-off data calculations whilst Taxiing

[ZS340]

It is apparent that a Major UK carrier,regularly departs the gate without receiving the final load-sheet via the ACARS. This information is usually received whilst taxiing out and then the take-off data is calculated and setup. I do not know the exact procedural details that they comply to, but I do know that quite often this "final" has not been received by the time they reach the holding point. They then advise ATC that they are unable to depart due to the fact that they have not received the applicable data or need time to calculate their speeds/thrust settings and performance limitations etc

They then block the taxiway for everyone else until they have the required data. At FACT this means no one moves. I have been stuck behind them twice at FAJS in the past month and my F/O reported the same happening to him at FACT.

Is this his normal practice i.e. SOP?
I believe that this procedure could result in an incorrect T/O data calculation which could have disasterous results.

If the data is being processed whilst the aircraft is moving then surely lookout etc. is being compromised.

As an outsider looking in it just seems an unsafe practice which gains very little, and in my humble opinion is poor airmanship.

I do think it is very selfish, with little regard for other operators.

ATC should not allow it, if one is not ready with regard to T/O data,then one should be instructed to vacate the taxiway and return to the ramp, or the very least to a holding area, allowing others who have complied with their SOP's and have made the necessary calculations, to depart.

[HotDog]

Not an unusual occurence. Had to re-calculate T/O data, many times due to change of duty runway after push back.

[ZS340]

Hot Dog you are missing my point. Yes there are times when t/o data has to be recalculated due to runway changes etc. However if one is expecting that, one normally loads the alternative runway in the secondary flight plan if one has that facility available. In your example EVERYONE is in the same boat and delays in departure are often inevitable when there has been a runway change...I find it unacceptable to be delayed because one operator chooses to calculate takeoff performance at the holding point, and the runway hasn't been changed for days.:ugh:

[caevans]

I almost always pushback and taxi before I receive the final load data. That is the way my company operates. It has to do with the lead sending the load information to load control, load control's entering the data into the system and the final numbers being datalinked to our flight. Most often it all comes together and we are ready to roll into position on the runway when we arrive.

At some stations delays are normal and I advise ground control on the way out that we may not be ready at the end so they can sideline us if necessary.

Sometimes less experienced crews get caught and block departures. They soon learn.

Happy Landings

[stilton]

Sounds like a certain US Airline lacking in paint, they never seem to have their numbers ready approaching the runway and either pull off to the side or delay everyone else..

[throw a dyce]

ZS340,
We have had trouble with a major UK carrier.Early in the morning they are unable to get the data,because of the number of requests at the same time.Unfortunately we are unable to pull them to one side,so it's on the runway,taxi down and join the back of the departures.
It's not as bad as it used to be,but still happens a lot.

[TopBunk]

This information is usually received whilst taxiing out and then the take-off data is calculated and setup.

Incorrect. The takeoff performance is calculated before pushback using the provisional data. 9 times out of 10 it covers the eventual actual TOW and no reprogramming is needed. The ACARS final figures will come through as 'CHANGES' or 'NO CHANGES'.

The general principles work well and save the time getting a final loadsheet to the aircraft.

The issue at FAJS and FACT is to do with the time in getting the numbers back to the aircraft. This may well be a dispatcher issue at these stations as generally it works quite well at most places nowadays. There are comms issues with the handling agent at JNB and at CPT there are issues with the generally short taxi out time and no holding area which can be embarassing. For that reason, some of us won't push straight away but give it a few minutes at CPT.

[backofthedrag]

We normally get the final zero fuel weight a few minutes after check-in closes - infact we cannot complete fuelling until we have the final ZFW - things are that tight . The final is rarely more than a ton adrift to the prediction at report time . The figures have already gone in as the tables move in steps of five tonnes and interpolation is rarely worth it .
The load sheet arrives by ACARS in its own sweet time and there is just the trim to set .

[Haven't a clue]

Previos discussion here, I think:

http://www.pprune.org/questions/361799-ba58l-blocks-taxiway-cape-town.html

[ETOPS]

ZS340

They then block the taxiway for everyone else until they have the required data. At FACT this means no one moves.

Not when I'm in command it doesn't............:=


Brakes off on stand to trigger the ACARS "off" signal then wait at least 15 minutes before calling ATC for push back. After carrying out a normal push and start procedure (and offering to give way to our friends in SAA Cargo ) the final figures arrive just before we reach the threshold. As Topbunk says the incidence of "revisions" to those figures is very rare so I often get take-off clearance without stopping on the taxyway :ok:


Now, what about the A340's poor climb and cruise performance leaving LHR.....

[Thunderbug]

ZS340

If this is regularly creating problems with ATC; surely you have approached the operator about sorting out their problem.

Some places have their own local procedures. At Italian airports we are not allowed to pushback until final figures are received. With such an incentive - the loadsheet figures usually arrive before the last door close!

I believe that there are changes being made for the FAJS loadsheet operation. A different location is now processing the figures. There will be a period while the new system beds in, but there should be a marked improvement once that is complete.

Fingers crossed. :ok:

T'Bug

[FlexibleResponse]

I almost always pushback and taxi before I receive the final load data. That is the way my company operates. It has to do with the lead sending the load information to load control, load control's entering the data into the system and the final numbers being datalinked to our flight. Most often it all comes together and we are ready to roll into position on the runway when we arrive.

If that mode of operation is not a direct threat to aviation safety, then I don't know what is.

In most countries, only the Captain is authorized to approve the loadsheet. To do so, he needs to check a number of critical data items that the loadsheet is based upon. A signed copy of the loadsheet is then left along with the Captain's signed acceptance of the maintenance log with ground personnel. This then provides direct evidence of what the aircraft loading and maintenance state of the aircraft was purported to be in the event that the aircraft is completely destroyed in an accident.

To perform a loadsheet check, the Captain needs about 30 to 60 seconds of head-down time to check the sheet itself and sign it. What the heck is happening to the aircraft during this time as it taxys to the hold point? The Captain is necessarily out of the loop.

THEN, data needs to be accurately transferred from the loadsheet for the following:
1. Takeoff data needs to be calculated for the aircraft weight and specific runway and met conditions. This data entry and output must be cross-checked independently by another crew-member.
2. This take-off data then needs to be entered into the engine management system to achieve the correct engine thrust for take-off.
3. This takeoff data will determine the flap setting and this needs to be set on the flap selection.
4. Take-off trim needs to be calculated from the CG position or at least transferred from the loadsheet to the trim wheel setting and cross-checked.

It is not impossible to do take-off data calculations due to a runway change after pushback, but it is obviously is a direct threat to safety of flight.

But your airline ALWAYS does the loadsheet check and the takeoff calculations after pushback and on the run for every takeoff? Please tell me that you are working for an African or other third-world small aircraft airline?

Emirates very nearly had what would have been Australia's worst accident recently in Melbourne when the loadsheet data was either incorrectly entered or the takeoff data was incorrectly calculated and entered by the cockpit crew.

Gentlemen and aviatrixes, this is a no-sh!t heads-up warning to all professional aviators.

[Capt.Doughnut]

I have never read so much bull:mad: in one post!

How on earth is it a direct threat to safety? Ohh dear, some people have no concept of reality.

A provisional loadsheet is produced and handed to the captain. This has the figures which are expected for the flight. Not always 100% accurate but normally a good fair estimate.
These figures are initially used for speeds etc. The captain accepts this loadsheet, signs it and returns a copy to the dispatcher before flight.

After pushback the final figures are entered into the system to produce the final loadsheet figures, this data is then transmitted via acars (or a/g radio) to the aircraft. The flight crew get a print out of this on the flight deck and read it. This will show whether there is any changes to the original provisional figures or whether they are infact the same as the provisional figures which is often the case.
This loadsheet is acknowledged by the flight crew through acars.

If there are changes shown on the final figures, then the speeds etc are ammended accordingly, all prior to flight and in total comfort and safety. If it takes longer at the hold and delays people a few minutes then tough luck really. They will never depart without receiving & acknowledging final figures then making nescessary changes tp flight data.

As for the issue of taxying, i dont think i have heard of any taxying accident where reading the loadsheet has been a contributing factor.

Flexible responses 'no-****' response really is full of :mad: Are you some press associate trying to scald the names of major airlines?

Capt. D

[Rainboe]

This is NOT Rumours and News. It is quite regularly raised and discussed as in the past. It´s old hat now. Get used to it- that is how operations are increasingly going to be when the improved communications afforded by ACARs are going to justify their expense. Trying to make a ´safety´ issue out of it is laughable, and frankfully, a little pathetic. No aeroplane taxies out ready for take-off immediately. They all have checks and cabin checks and briefings to complete. It´s no different ´waiting for your figures´. The system will eventually settle down. Those of you in such a darned hurry would do well to relax and bit and learn some patience.

[411A]

Some places have their own local procedures....

ATC as well.
I've noticed twice now recently at JED, the lead airplane on the taxiway not being ready (and not having advised ATC beforehand)...sent straight back to the parking stand, pronto.

They then get the message, real quick, for future ops.:E

[Capn Bloggs]

Sounds like a dumb idea to me. As for Rainboe's idea of us slowing down, learning a little patience so he can do his takeoff data, that is a little selfish... I would have thought you could mount the same argument the other way: why are you so impatient to get off the gate (and possibly hold everybody else up) when you could be a little patient yourself and get organised before pushback?

Brakes off on stand to trigger the ACARS "off" signal
:ok::ok:

[Rainboe]

Your facts are wrong. You do not do take-off figures on the taxi out. They are precomputed before pushback. Fine to send people back to the stand for delays in the figures- that will also apply if you delay people on checks, and have to hold up take-off because the cabin checks aren´t done in time too?

This is the way the next generation will be doing it! Get used to it! Get over it too.

[777den]

Quote:
Brakes off on stand to trigger the ACARS "off" signal


Brake release trigger ACARS "OUT" and squat switch triggers "OFF"

[AKAFresh]

I think the point of this practice is that it can cause inconveniences both to ATC and other aircraft, I think if it was unsafe it would have been brought up and changed along time ago.

I experienced this very topic today after landing at LGW, we taxied to our gate and was told to hold while a major US carrier finished its pushback into the cul-de-sac and also wait for it to taxi to the holding point (not very far from its gate) before we could proceed.

After there push back they called ATC to ask if they could hold position because they had not completed their takeoff calculations and bugs. This did not go down well with ATC who was rather busy at the time and was told to taxi to the holding point regardless because right now he was blocking everyone!

Iv never seen an a/c taxi out so slow! I mean even the A380 does not taxi this slow. There were several aircraft waiting one on stand for push, us waiting to get onto stand and the rest were waiting in line for takeoff sequence. They did not show much appreciation to the fact that other a/c were waiting for them.

Now this may have been because they were partly heads down and taxing at the same time in which I can understand why they would taxi so slow, but this was also at the expense of other aircraft. LGW is not the greatest taxi layout but the taxi instructions to the US aircraft was simple enough because the gate was so close to the holding point, so it was not to do with complicated taxi instructions.

9 times out of 10 this practices probably goes unnoticed and generally works without inconveniencing others but I can see why the few times it does can irritate both ATC and other crews.

Its really no big issue, as long as it does not happen all the time, I'm sure ATC will bring in new procedures if it gets out of hand such as the ones imposed in Italy.

[sikalia]

In the company where i work for, loadsheet includes total pax on board,pax sitting distripution,i.e. What if there is a discrepancy on total pax onboard when they receive the final loadsheet?
Do they taxi back to stand?

[TopBunk]

What if there is a discrepancy on total pax onboard when they receive the final loadsheet?
Do they taxi back to stand?

The loadsheet signed by the Captain about 20 minutes before departure is a provisional loadsheet detailling the expected pax and cargo load and distribution thereof. The pax count may vary by a few, but we do full pax/baggage reconciliation and will not depart without that! I have had to return to stand, but that was for a misloaded hold - departing with a non-allowed combination of ULD's.

The system allows for variation in pax numbers and loading within certain tolerances before generating a CHANGES message. The change tolerances vary by aircraft type (less tolerance for a small aircraft, as you would expect), and will be for TOW and trim. Outside the tolerance and you have to inspect the changes and re-confirm the performance data. Note: the TOW may be down - it is rarely up, as they factor the male/female split after doors closed, and the performance is generally in your favour. On the 747, you normally find that the assumed temp thrust reduction methos gives you 2-3 tonnes or margin, which equates to 20-30 pax increase! and is therefore rarely a factor.

[groundfloor]

Ouch, why give the holes in the Swiss cheese more chances - the amount of ZFW changes over 4000 kg`s are not that infrequent to be ignored ie: sorted out on the way to the runway.

1. On Airbus FBW once the engines are started you can no longer enter the ZFW as a ZFW but must enter the weight as a Gross weight on a different page which the a/c will then work backwards to a ZFW - so a different page with a different input means a non standard way - anything thats non standard needs more attention.

2. Your paper flightplan generated on the ground by a ground based computer becomes less and less relevant as the ZFW changes - when do you ask for a new one. 4000 Kg seems to work for the 340.

3. Yes it is also possible to uplink the whole shooting match to glass aircraft - sort of removes the drivers airframe from the loop to a large extent: who selects how much you flex/ de-rate which V1 to use ,anti - ice, flap settings etc... Getting the correct information to the a/c is important then let the people in front make the plan.

Yes we have to do change figures when it`s unavoidable - runway change, sudden rainstorm with a now wet runway. Why leave the gate with something so important still incomplete? If you are still at the gate and you are not 100% happy there is no pressure - I`v been in a situation where we opened the cargo doors to double check due to a 2nd ACARS "final" loadsheet 15000 Kg lighter.

Less haste - More speed

[TopBunk]

Groundfloor
2. Your paper flightplan generated on the ground by a ground based computer becomes less and less relevant as the ZFW changes - when do you ask for a new one. 4000 Kg seems to work for the 340.

5 tonnes on a 747.

You clearly do not understand how the Provisional Loadsheet system works, perhaps we haven't explained properly - either way, we have been using them for 18+ years in BA, with advances (ACARS etc rather than voice) and belts and braces in procedures along the way to try to ensure integrity of the calculations for performance. Thus far it has worked for about 700 departures per day (x 365 x 18) = 4.5 million flights, without any MEL/AKL type incidents.

When you can statistically argue your case from a position of knowledge and experience, then come back and argue it:hmm:

[captjns]

I have experienced extra taxi delays behind the silver fleet departing MIA.

[JW411]

I really don't know why this topic is such news. The first time I came across getting the "final figures" whilst taxiing out was on my way to the reef runway at Honolulu on my way to Nadi.

The year was 1983.

So what is new?

Why do you want to know where everyone is sitting?

In Laker (British CAA) we had to list exactly how many passengers were sitting in Compartment A, B and C (DC10) and whether they were male, female or children.

When I flew the exact same aircraft on the N register, the FAA were not so insistent upon such detailed information.

They only required the total passenger numbers for they figured that the first passengers on board would sit by the windows, the second lot would sit in the aisles and the remainder would fill the middle seats.

I do not ever remember such a practical solution ever causing me the slightest problem.

Life is basically simple; only people make it complicated.

[oceancrosser]

I find nothing wrong with how BA do the loadsheet thing for as long as they are not allowed to hold things up at the departure end.

I would however like to know what on earth you BA lot are doing post push-back and prior to taxi (other than starting up)? Seems to take BA longer than most to get ready for taxi. I especially notice this at the BA terminal at JFK. What are you folks up to?

[AKAFresh]

Having a quick shot! Steady the nerves! :}

[PositiveRate876]

Late "final numbers" were an issue with the previous company I worked for. However the ATC at my base was fully aware and an informal procedure was in place where on first contact with GND, the pilot would call:

"XXX####, (position) with numbers / negative numbers"

Then you either get the taxi to the runway or join the rest of the guys in the holding bay.


Present company all is done 20min prior to gate departure.

[wiggy]

What this lot "is up to" is the little matter of getting Air Traffic permission to move....

Unlike most airports the normal procedure at JFK is that when ready to taxi you call the first Ground Frequency, that controller puts you in the system as ready for taxi, then hands you off to the next Ground Controller who will eventually clear you to start taxiing and actually leave the BA Ramp area and join the line out to the runway ...... I suspect :ok: it's a similar deal for any airline taxiing at JFK.

[My 737]

I have waited behind aircraft's not ready because of performance calculations, (waiting for final numbers) and it is unacceptable.
If you are not done with absolutely everything, don't push!
ATC shouldn't allow a/c to push until final figures received, period.

Ready on reaching...........;)

[remoak]

Funny really, a system designed to make the day more efficient that requires you to "slow down and be patient".

That's progress!

[BenThere]

As I am paid by the minute and not by the mile, I'm not too concerned if the airplane ahead of me needs a minute or two for whatever reason.

Common courtesy suggests, though, that you shouldn't pass the last escape from blocking the runway without numbers if possible.

In my experience, 80 percent of the time the numbers come right after pushback as the first engine is being started, and 99.9 percent of the time all checklists are complete by the time I'm cleared for takeoff. In that rare, rare case when I'm not ready I've found the following to work: "Tower, we need a few more minutes, what would you like us to do?"

Would that make anyone angry if they heard that? If so, I believe the problem is yours, not mine.

[TAVLA]

ATC should make aircraft that are not ready at the hold, enter the runway and vacate to the back of the queue.

As an aside I have noticed BA takes an extraordinary time to request taxi after pushback at HKG as well.

[DownIn3Green]

silly, silly, silly...The Captain should koow how much the A/C weighs, how much fuel is on board (minus taxi fuel-which as we all know is always stated on the "lean" side) and how much payload is onboard...

Time to go is time to go...If one can;t figure it out without computers and ACARS, well, maybe one should bring back the trusted F/E...

[411A]

well, maybe one should bring back the trusted F/E...

HA!
We never 'lost' him.:ok:

...but in my airline we do EVERYTHING at the gate, even briefing, if possible.


Likewise, and far better in my opinion.

[Tankengine]

My company uses the provisional system as well but we get final before pushback, we allow 3 mins between final loadsheet arrival to pushback to enter into FMC and finish checklist. No head down calcs whilst taxying!:)

[Tower Ranger]

The Ba a/c do take significantly longer to get fully ready for departure at DXB which is not a problem if you are taxying for a 30R departure but I always try to put them somewhere that I can get other traffic to the holding point ahead of them as it can be a solid 5 minute delay at the 12R holding point.

Never mind ATC and the guys behind them in the queue, if I were on the flight deck i`d be geting a bit hacked off with it too which can`t be the best way to start your journey.

[Pontius]

There are too many people here who aren't reading what's written; either because they are skipping the information or because they chose not to so they can 'BA bash'.

The performance calculations are NOT done whilst taxying. They are done before push-back and the FMC entries are complete before push-back. The calculations are done using the provisional figures, from a loadsheet that is signed by the Captain (as required by law). In the time I flew for BA I only had a ZFW that was higher than the provisional loadsheet a handful of times and, even then, the new TOWs were well within the assumed temperature TOWs that had been calculated and entered into the FMC BEFORE push-back, so nothing had to be touched (and no delays caused as a result).

So, the reasons for the delays? Generally two. The first concerns some places (JNB a classic example) where the groundstaff are so crap at getting the final figures into the system and then sent via ACARS to the aircraft that the pilots are left waiting for them. For obvious reasons they are not going to get airborne without them, so they have to wait. The trouble is, it's not consistent. So it's no good asking ATC for a delay tactic as you await your final figures because you can bet on that occasion they will come through straight away. The stations that cause the most problems have been told time and time again to sharpen up but what do you do? In JNB the station staff do not answer the radio, they do not answer their mobile phone numbers as posted on the info sheets and, the last time I was there, the only way we could contact them was for us to ring London on Satcom and then get LHR Operations to call JNB direct. Not ideal, as you can see, and certainly not the fault of the pilots if some people are delayed whilst taxying in these 2-bit locations. The second reason for delays are because the cabin is not secure. We've gone round and round on this one hundreds of times but, at the end of the day, for whatever reasons, until everybody is briefed and buckled in then the aircraft ain't going anywhere. Most airlines are better than BA at getting the cabin ready quickly, simple as that but, again it's not consistent and some crews are excellent at getting the cabin ready. If you're frustrated in JNB, just imagine the poor air traffic controllers at LHR :(.

So, is there a safety issue here? Definitely not. I've done it the BA way and I've done it other ways. BA do not calculate whilst taxying and the SOPs for data entry and calculations are better than the other outfits I've flown for. They are far more stringent on doing these things in a set manner and there is far less room for pilot judgement (and, therefore, mistakes). So, for the scaremongerers; back in your box. Just because you wait for the final figures at the gate doesn't mean that's the way it has to be done (especially with pax flying versus cargo flying) and, as has been pointed out, BA's success rate is testomony to the fact that it's not dangerous. As for the EK incident; I do not have a clue about EK's SOPs for ensuring the data is cross-checked and entered correctly (IF that had anything to do with the tailscrape at all). All I can say is that BA's procedures do ensure everything is on the safe side and there is absolutely no safety issue involved.

Why do BA take so long to push and start i.e. why is it so long before they can taxy? Well, I would suggest that at the stations mentioned CPT, HKG & JNB it is a function of temperature/airfield elevation. At all of these places we're talking about BA 744s. Normally they would start 2 engines at a time but, when the temps get up they have to start one engine at a time and, in the case of JNB, they will be doing manual starts as well (as opposed to auto-starts). Again, for obvious reasons, this is going to take a lot longer than normal and may well be why you see the clock ticking longer between pushing and being ready to taxy. The old accusations of slow taxying for extra money etc went out the window with the flying boats. It's got nothing to do with extra cash, nor trying to piss other people off because, at the end of the day, the BA pilots want to get in the air just as quickly as you do. Can you really imagine, for one moment, that it is a lifelong ambition of a BA crew to be sitting looking at the taxyway markings in JNB?

I have no vested interest in the way BA do things, as I no longer fly for them. What I can say, however, is that cries of 'unsafe' or 'dangerous' are so far off the mark that they should be consigned to the bull**** pile. Inconvenient for other airport users, certainly, but hopefully you'll now know why those BA Jumbos are taking so long to get into the ether and realise it has got nothing to do with trying to piss anyone off.

[sweetie76]

Yep!............

[sAx_R54]

FlexibleResponse
Please tell me that you are working for an African or other third-world small aircraft airline?

Up until your sixth para, there may have been some validity in what you have to say. I would have thought that neo-structural imperialism would have had no place in what appears to be a very serious issue!

Recent incidents in Amsterdam, France, Spain, Japan, Buffalo NY, etc appear to suggest that accidents/poor operating procedures are not strictly the preserve of the 'culturally backwards', as you appear to indicate.

sAx

[FlexibleResponse]

sAx_R54,

Fair Cop young fella!

That was an intended ironic comment on supposedly the best Western airlines in the world conducting absolutely dangerous procedures to cover for the deficiencies of their ground support crew in providing timely information to their operational crew.

It is indeed ironic that we aircrew allow and even condone the slack work operating practices of our ground teams and compromise the critical time before take-off in making up for their company or personal deficiencies.

This is not only not necessary, but it flies in the face of flight safety. Why do we aircrew have such trouble in recognising such errors (threats to safety)?

Because we can do anything that is thrown at us with aplomb and we have bigger balls than anyone else, but of course...

Edited to include phrase "(threats to safety)".

[Rainboe]

Justify 'dangerous procedures' please? Just about the safest airline in the world- how do you explain that? No take-off tailscrape attempts due to inaccurate weights! The system works well and safely. You cannot accuse BA of that- operations have been supremely safe. It is time the rest of the industry was brought up to date!

[411A]

Just about the safest airline in the world- how do you explain that?

You tell 'em, Rainboe....and he may be right.:}
I have flown in the past with seconded BA First Officers, and I must say they were very well trained...top notch every one.
Seconded Qantas guys weren't bad, either.

[Nicholas49]

They're just jealous they don't work for such a good airline. Nothing like a bit of anti-BA ranting when you're not lucky enough to work for them.

[PJ2]

studi;
Why dont you just get final figures 10 min before off block? Check in closes way earlier than that.
That's exactly what we did at the airline I retired from - it was an excellent procedure which enhances safety in my view. In the cockpit check we use the flight plan numbers to calculate the takeoff data. We do that about 40 minutes before departure.

The next two times we handle the data are generally a fine-tuning process, not calculating from scratch, (I suspect most carriers do it this way). About ten minutes before departure we receive a preliminary load calculation and revise as necessary. The data is entered and is given a full verbal review and briefing to the entire crew (2, 3 or 4 as the case may be). There are many opportunities to error-trap up to this point.

We push and taxi and on the taxi-out the load final is received and compared with the preliminary data. Almost always, no changes result.

If there's a big load change (freight, usually) or a runway change the data is re-calculated. Our SOPs permit data-entries while taxiing. Most will delay any such work until across all runways. The data incidents I have become aware of were generally upstream of the cockpit process.

The sterile cockpit is the key to preventing almost all errors.

Unfortunately, short turn times even for overseas aircraft do not permit the luxury of a sterile cockpit during the cockpit check, especially if the aircraft has a snag that maintenance is trying to fix or a new MEL item that they're trying to secure and sign-off on. The captain must be aware of all this activity and unless airlines double or triple an aircraft's time on the gate, (less time on the ground is more airplanes in the system without buying more airplanes if you know what I mean), there is no way to avoid this. Managing distraction successfully is a primary, not secondary, task for crews.

Our takeoff data is from the ACARS on some fleet types, from laptops on other types but the procedures don't vary.

[Ex Cargo Clown]

This procedure is completely safe and far from dangerous as other people on here seem to think :ugh:

Certainly safer having well trained Ops people giving you figures by ACARS than having one person working them out in a crowded flightdeck on a laptop...... (see EK accident)

I believe the SOP came from the lack of stands on T4 and now to some extent T5, so essentially the lack of slots at LHR are to do with this. Certainly not BA's fault.