"Getting the numbers"?
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"Getting the numbers"?
I was recently briefly held up by a BA wide-body at the holding point while the apologetic crew explained that they were "waiting for the numbers" from their Ops department.
Can somebody explain what exactly "the numbers" are, and the process involved in obtaining them? I presume that this data is a bit more complex than just Vspeeds, otherwise surely the onboard FMS could calculate them? Are they, for example, a detailed flight profile based on actual passenger count and latest forecast wintem aloft data? Why is this seemingly calculated at the last moment - in this case as the aircraft was at the holding point - rather than a few minutes before push-back?
Can somebody explain what exactly "the numbers" are, and the process involved in obtaining them? I presume that this data is a bit more complex than just Vspeeds, otherwise surely the onboard FMS could calculate them? Are they, for example, a detailed flight profile based on actual passenger count and latest forecast wintem aloft data? Why is this seemingly calculated at the last moment - in this case as the aircraft was at the holding point - rather than a few minutes before push-back?
Last edited by Trim Stab; 27th Dec 2013 at 05:26.
SkyGod
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The latest load information with final pax count, weight and balance data as well as stab setting, etc.
Sometimes the "numbers" are delayed but usually shows up a few minutes or seconds are the doors are closed.
Sometimes the "numbers" are delayed but usually shows up a few minutes or seconds are the doors are closed.
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I've been delayed by them as well. IMO they shouldn't push back without them. If they do, and don't receive them in time to take off in order, they should get out of everyone else's way!
TS
As I'm sure you know we don't know your exact weight/balance until the doors /holds have been closed, so we load up provisional figures in the FMC.....we could then sit on the gate waiting for confirmation of "the numbers" from load control or taxi out in the expectation that the confirmation of nil change or significant changes will be communicated to the crew before getting to the runway - the BA SOP is to take final figures on the taxi out via datalink and AFAIK many/most operators do the same.
Where the BA system does often seem to be particularly bad compared with other airlines is the length of time it takes to get the confirmation - I can promise you it's been a source of frustration/annoyance for years and has resulted in countless datalink demands, VHF calls to company and even satphone calls to load control from downroute (whilst stationary of course
). It's all potentially very distracting.........personally I'll always try and let ATC know we may have a problem whilst there are still options to "sideline" us.
And yes, management certainly do know - please don't (always) blame the Flight Crew, give us the tools and all that.....
Where the BA system does often seem to be particularly bad compared with other airlines is the length of time it takes to get the confirmation - I can promise you it's been a source of frustration/annoyance for years and has resulted in countless datalink demands, VHF calls to company and even satphone calls to load control from downroute (whilst stationary of course
). It's all potentially very distracting.........personally I'll always try and let ATC know we may have a problem whilst there are still options to "sideline" us.And yes, management certainly do know - please don't (always) blame the Flight Crew, give us the tools and all that.....
Last edited by wiggy; 27th Dec 2013 at 08:01. Reason: trimming
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Hang on, so you don't know how many POB you have when you taxi? Or more pertinently you're happy to close up and taxi without having that info? What happens if you need to evacuate the aircraft and do a head count?
so you don't know how many POB you have when you taxi?
Or more pertinently you're happy to close up and taxi without having that info?
What happens if you need to evacuate the aircraft and do a head count?
Being optimistic the crew will give the provisional figure to the incident commander.....whether he/she is interested in an "on the nose" POB whilst folks are still coming down the slides is only something they can answer. In the real world in the event of an incident involving a full widebody I suspect by the time passengers and crew had been rounded up, led away to safety and a head count could be performed in a controlled and meaningful manner the final POB would be available to the authorities.
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Thank you for your informative response.
I never knew the uncertainty held about how many people were on commercial aircraft at a given time! I always thought there were people at the door with clickers?
The likelihood of the aircraft catching fire on starting engines must be deemed low enough that in the event that it were to happen then people who are managing the incident on the ground need not know how many people they should be expecting on the nose?
I appreciate that Ops would probably radio the info to the Rescue Services but I wouldn't feel right not knowing how many people were on my aircraft when the doors close! Guess you must just get used to it.
I never knew the uncertainty held about how many people were on commercial aircraft at a given time! I always thought there were people at the door with clickers?
The likelihood of the aircraft catching fire on starting engines must be deemed low enough that in the event that it were to happen then people who are managing the incident on the ground need not know how many people they should be expecting on the nose?
I appreciate that Ops would probably radio the info to the Rescue Services but I wouldn't feel right not knowing how many people were on my aircraft when the doors close! Guess you must just get used to it.
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The FMS needs info to be input manually, unless there are scales attached to each section of the aircraft! You need to tell it the mass of the pax and baggage in order for it to do it's calculations.
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while I don't fly for BA, my airline does a head count, and compares it to a ticket count/boarding pass count and we get those numbers from the flight attendants. this should allay the fears if an evacuation happens.
however, the FA head count is compared to the gate agents ticket count and must be reconciled before takeoff.
we have taken off with ''the numbers'' only to get new numbers three minutes after takeoff.
so, naturally we return for landing and takeoff with the right numbers (kidding of course!)
but it is important to get the right numbers, even after the fact to calculate landing weight and Vref.
and if you are delayed by some company like BA, be smart and request an alternate taxi route so you can get to the runway, even by back taxi.
Smart pilots like to leave extra room behind other planes in case of problems, either numbers or mx so they can keep going via another route.
however, the FA head count is compared to the gate agents ticket count and must be reconciled before takeoff.
we have taken off with ''the numbers'' only to get new numbers three minutes after takeoff.
so, naturally we return for landing and takeoff with the right numbers (kidding of course!)
but it is important to get the right numbers, even after the fact to calculate landing weight and Vref.
and if you are delayed by some company like BA, be smart and request an alternate taxi route so you can get to the runway, even by back taxi.
Smart pilots like to leave extra room behind other planes in case of problems, either numbers or mx so they can keep going via another route.
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personally I'll always try and let ATC know we may have a problem whilst there are still options to "sideline" us.
And yes, management certainly do know - please don't (always) blame the Flight Crew, give us the tools and all that...
And yes, management certainly do know - please don't (always) blame the Flight Crew, give us the tools and all that...
You already know there is a systemic problem; so failure to anticipate a common repeat problem and take reasonable action to avoid delaying other flights, is a personal failure.
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Spot on, Intruder. In my day, most of the stuff was done on the radio due to lack of ACARS fit (even more distracting!) and often 'late'.
The system can work well, can achieve the 'Holy Grail' of 'on-time push' for the company BUT does require an Ops/Load Control that is on the ball and a flight crew prepared for the occasional delays in 'ready' so as not to delay others.
The system can work well, can achieve the 'Holy Grail' of 'on-time push' for the company BUT does require an Ops/Load Control that is on the ball and a flight crew prepared for the occasional delays in 'ready' so as not to delay others.
BUT does require an Ops/Load Control that is on the ball and a flight crew prepared for the occasional delays in 'ready' so as not to delay others.
, perhaps a a 10 year old fax machine hidden away in some back office might not be up to the task.... and there's also a need for investment to make sure there are enough qualified dispatchers on duty at the receiving end to ensure that the figures are processed and sent back to the aircraft ASAP....Oh, did I mention there's a need for investment
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Remember also that the 'final' figures will account for the male/female passenger split which will also affect the notional W&B, which could never be picked up by 'clickers' and which are not used by BA anyway(*).
(*) In BA the reconciliation of the pob is done by the groundstaff and not by the cabin crew.
(*) In BA the reconciliation of the pob is done by the groundstaff and not by the cabin crew.
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You report for brief and get a "plog" with a planned ZFW.
The weather, opdefs and notams folder info contains yet another ZFW
Then a "provisional" loadsheet is presented with another ZFW.
To which is added a fiddle-factor (+1,000kgs for the 737) and this is loaded into the FMS and used for takeoff perf, if the final and 5th ZFW passed by load control is within +1 ton or -2 tons of the original. If not "in compliance", then loading and perf and SID have to be done again on whatever taxiway/holding point before departure.
Having been exposed to FIVE different ZFWs, you now get airborne and somewhere up the climb when things are quiet, if having launched on the "fiddled" provisional weight/mass, then the real ZFW is loaded for cruise performance.
Perfectly normal stuff, all approved by the CAA, so that's all right then.
Don't bother to read the Boeing Magazine article on incorrect ZFW loading causing serious incidents/accidents, it no longer applies in this case.................................
The weather, opdefs and notams folder info contains yet another ZFW
Then a "provisional" loadsheet is presented with another ZFW.
To which is added a fiddle-factor (+1,000kgs for the 737) and this is loaded into the FMS and used for takeoff perf, if the final and 5th ZFW passed by load control is within +1 ton or -2 tons of the original. If not "in compliance", then loading and perf and SID have to be done again on whatever taxiway/holding point before departure.
Having been exposed to FIVE different ZFWs, you now get airborne and somewhere up the climb when things are quiet, if having launched on the "fiddled" provisional weight/mass, then the real ZFW is loaded for cruise performance.
Perfectly normal stuff, all approved by the CAA, so that's all right then.
Don't bother to read the Boeing Magazine article on incorrect ZFW loading causing serious incidents/accidents, it no longer applies in this case.................................
