Manual vs Automated loadsheets

[parttimer]

After an afternoon of manual loadsheet training, we came up with a few issues.
The main one being....
How the hell can there be such a difference between the trim on a manual loadsheet directly compared with an automated one.
Ok there is probably some give and take/margin for error but how can there be such a difference?
Set up of systems or just accuracy (or not depending on how thick your pen is) of manual loadsheets?
And furthermore does the minimal difference really matter?

Discuss.....or don't???

[Flap15Geardown]

On many types the difference is down to how the pax load is trimmed. On all manual loadsheets it is by area or bay split. Computerised loadsheets vary, some trim by area and others by row. Trim by area should give the same as your manual loadsheet but trim by row could give a very different result as it takes account of who sits in which row, if you are bored try moving a few and see what difference it makes! One good example that springs to mind are Swiss Er145's, they trim by Class. if its out of trim and not full you can change the version to a better business/economy split and get the aircraft back in trim without moving any pax. The difference between manual and computerised doesn't actually matter as both types are legal and still leave room for error as they use standard pax weights and often standard bag weights. If the limits shown on the loadsheet were the physical limits of the aircraft you would have to weigh all pax and plot every row, because of this most Captains won't have a problem with your 'thick' pen.

[RampTramp]

Interesting point parttimer. When we introduced our 'new' automated system, we had to demonstrate to both the operators and relevant CAA's that the manual & automated loadsheets were tha same (give or take the allowance for error on a manual sheet). In all cases we were able to prove same. That said, we are a cargo operator and work on known weights rather than 'average' pax weights.

At the end of the day, most manual sheets are a compomise with restricted envelopes to ensure that any error in calculation will not put the aircraft in an unsafe state. In my time I've seen and used just about every type of manual sheet, drop line, Xmas tree, adjusted weights, whizz wheels etc. and even resorted (in my young & foolish days!) to the 'shiny bit of the nose gear' calculation!

At best, a manual sheet will give you a result that could be up to 10% out while an automated system, if properly set up, will give an accuracy down to 2 or 3 decimal points, assuming correct weights are used. That said, the automated system will still only give an approximate figure is 'standard' weights are used for pax & baggage. The old addage of 'garbage in, garbage out'.

Responsible operators will recognise this and, like the manual sheet, will curtail the envelope to ensure the aircraft is never out of limits.

Based on the above ramblings, comparing a manual to an automated loadsheet will always show some diffence because of 1) the thickness of pen & judgement of the person completing it and 2) the compromises made in the production and printing of the manual sheet.

RT

[Opssys]

Any Loadsheet is the most accurate assessment of a situation that has so many built in inaccuracies (starting with the period between that last time the Aircraft was weighed accurately and the date the loadsheet was produced). I have always admired the Weights Engineers who work out the safe trim envelopes and trim datums that allow for the standard weights and the other variables which in day to day Aircraft Operation we take for granted.

Long ago and in another place my load Control proficiency exam involved starting with an aircraft with no seats and then working to the standard configuration specification adding these in to provide the aircraft prepared for service weight and trim datum, then going through the process of adding the various catering weights, fuel load/burn, crew and finally the commercial load.
Through the rose tinted view of memory good fun, but in writing this I now remember it was a real 'b*gg*r!

Automated systems rely on the Semi-permanent data being maintained accurately and assuming this is the case, then the automated system should produce a 'better result', but there still a reliance on human factors (Trim Plan being followed, etc).
Anyway I am now rambling
DIH
DIH

[parttimer]

As with any job you are correct human factors come into play quite alot with automated loadsheets.
There have been more than one (hundred) occasions in my career when airlines and systems maintainers (or whatever you want to call them) do not keep systems updated. Ok it is a necessary requirement that the weights are checked before any loadsheet is produced but at what stage do you rely on the printed matter from the airlines or that i the system.
A certain main operator never sends us updated weights we just rely on the ones provided in their automated system.
another operator sends updated weights every other day and we never know when they are in use or which issue we are to be using on which particular day. Another provides us with weights but never sends them to the systems people so we have to change them manually every day!
You'd think it would be a slightly more serious matter.

[Opssys]

Following on from Parttimers comments.
IATA (bless their Technical Groups), have stressed the importance of the distribution of Load Control semi-permanent data for automated Weight and Balance for a very long time. Unless it has changed recently there is a section in the Airport Handling manual on this subject with pro-formas.

What IATA cannot do is actually force Airlines to put in place good practises to ensure this is done accurately and in a timely manner.

The data flow in summary should be:
Airline Weight Engineer or other responsible (and accountable) Section defines the Change and effective date (this may be immediate, or hopefully around 7 days)
the information is promulgated internally to the relevant sections.
Including the one responsible for updating the Stations

The airlines Ground Operations Support Section (or equivalent), then should distribute the information to all Handling Agencies.
Stressing both the effective date and requesting acknowledge of receipt and action.

At the handling agency level, the information should be internally distributed to both Load Control Support (probably one person) and DCS/Load Control System data administration (again probably one person). Load Control Support as the Accountable Section need to ensure the data is updated both in a timely manner (immediately would do) and accurately.

The chain is short and the error level should be very low!

However this assumes the staff throughout the chain, understand the importance of the information and are responsible and accountable for their involvement in the timely distribution and/or accurate update of the supplied information.

Unfortunately it does appear that due to cultural, training and other changes which have been going on for the last decade
a large number Airlines and Handling agencies have reduced both the status and the emphasis of their support sections, in some cases reducing them to purely clerical admin sections with little or no understanding of what passes through their hands.

In which case basic information is not distributed in a timely manner, or is updated inaccurately (with no oversight check)
and then parttimer and colleagues get it in the neck!

It takes time (and some money) to build competent professional support sections and 10 Minutes and some instant money savings to destroy them

Rant over!
DIH

[parttimer]

well i'm glad someone shares the same experiences, I really do feel it should be something a little more important in our tiny meagre existences in the great scheme of things!!
thanks for your comments any more welcome on this subject.

[Hyper_Dispatch]

Hi PartTimer,
Sorry to intrude but there shud be much difference btw manual and automated. If there is a BIG difference then either the manual is done wrongly or the data for the autmated system is wrong somewhere. Load Masters or Weight & Balance officers first of all needs to be train manually for the Loadsheet. This will give them the neccessary fundamental/basis of basic aircraft planning. Once the know how to 'do' or complete the manual then thats where the automated will comes in. Automated basically helps the 'loadsheeter' to perform faster and more efficiently if there is any changes to the planning/loading/weights like passengers/cargo/baggages/fuel..etc etc. But hey I'm not a pro in this matter, lol. :}

[Opssys]

Hyper_Dispatch.
There should be NO Difference in the Weights (providing correct/latest basic data used).
But there will be differences in the Trim.
Using Manual Trim Charts or (god awful) Whizz Wheels, builds in small errors. Some of these errors cancel themselves out, some are cumulative. Because of the design of the Trim Charts, the result is still safe, but from comparision testing Computerised Weight and Balance Systems against production manual loadsheet/trim charts (a long while ago), the differences can appear large!

I believe all staff who's job involves Loadsheet/ Load Planning functions, should receive training in Weight Balance basics and then production of all manual Load Plans and Loadsheet and Trim Charts.

I also believe that Whizz Wheel Trim Calculators should be banned (but I accept that isn't going to happen any time soon).
DIH

[Hyper_Dispatch]

Hi Opssys
That's what I meant, the weight must be the same, only the trim. And yes, before they need to train with the basics/manual first and get it right.
As for the wheels, I agree but it adds to the challanges of doing manual loadsheet for DC10 and MD11, hahaha. :8