25th Apr 2012, 18:30
I'm curious to know - how do pilots do weight & balance calculations?
Is by pen/paper, with spreadsheets or via a tool in the cockpit?
Also, is there usually a lot of room for error, or have there been any critical/fatal accidents due to errors made in the calculation?
29th Apr 2012, 01:57
All of the above.
As part of a private pilot exam, you do a sample pencil calculation to show you grasp the fundamentals. But in practice, you'll probably do it digitally. And an airline dispatcher prepares W&B for every flight, probably optimizing cg for best efficiency.
29th Apr 2012, 06:25
Remember the US style dispatcher is purely a north american thing as far as i'm aware. The rest of us doesn't have that luxury. However centralized load control is a normal thing within many airlines, loading will try to put the CG as far back as possible to save fuel within commercial constraints.
We used to use paper forms a long time ago, then switched to EFB (electronic flight bag) W&B which was integrated into the performance calculation suite so there was no possibility of wrong inputs into the performance calculation (although there was in the weight and balance part), nowadays it is centralized load control and load and trim information is sent via ACARS into the flight deck. In the future (next one to two years) it will go via wireless network (WLAN or cellphone) or SATCOM directly into the EFB which is interconnected with the aircraft systems.
There have been accidents caused by weight and balance errors and there is one big issue still since airlines use standard weights for passengers which are usually on the low side (at least in most western countries). Then there is the issue of number fumbles with performance calculations which has lead to accidents in the past and will lead to more in the coming years.
29th Apr 2012, 07:12
Raysofsun. If you are really interested here is some Sunday breakfast reading for you: http://www.faa.gov/library/manuals/aircraft/media/faa-h-8083-1a.pdf :)
29th Apr 2012, 09:51
UK fatal accident where loading and CofG was a contributory factor
29th Apr 2012, 11:00
Get a Loadmaster to do it for you! Sadly not used very often in Civvy Street
Total moments divided by total weight = CogG position from datum
29th Apr 2012, 11:19
Most of the time, it's produced by computer for us. At more 'rustic' airfields we do it ourselves - numbers, lines and all!
29th Apr 2012, 13:14
A tool in the cockpit? According to most of the crew I fly with, there are usually two of us ;)
29th Apr 2012, 14:08
It's quite concerning how many airline captains struggle to produce a load plan and load sheet for their aircraft :hmm:
In Europe at least, most loadsheets are either produced by the dispatcher (who is weight and balanced trained) or via Centralised Load Control (CLC). Most airlines opt for CLC with the exception of people like Easyjet/Air Berlin who use a 'less paper cockpit' environment to produce the loadsheet, it's done by entering pax numbers / fuel figs / bag figs into a computer, information is passed to them by the dispatcher.
You can also do a manual loadsheet for any aircraft but this tends to be quite rare, other than small props and the like. Ryanair dispatchers produce a manual loadsheet for their flights but it's different than a 'drop line' one and fairly simple once you know what you're doing, some very clever mathematics are involved.
So in short, the captain/fo SHOULD be able to produce a load plan and load sheet but in reality they rarely do, and would probably struggle to produce a manual load sheet for lets say a wide bodied TATL flight.
29th Apr 2012, 14:22
Ah drop lines, wizz wheels and index changes the delites of manual load sheets. When I first started at Gatport Air Wick nearly 35 years ago we started with a weeks training on loadsheets before being let lose on the ramp. Now remind me Comet 4C I div nose up? Where is Tibby when you need him...........
29th Apr 2012, 15:01
We use our computers (LPCs) as said above to do the calculations, and if it is INOP for some reason we then talk to operations who have their own ones
29th Apr 2012, 20:30
I spent quite a few years doing manual loadsheets in the days before computers came in. Many days our Luton Airport office was stacked high with partly completed loadsheets when Heathrow divertions came in and we were waiting for the actual load details to be advised for their onward trip. I then moved on within aviation but later was back doing manual loadsheets for domestic airlines in Australia. Computers then came in and almost anyone could then do a loadsheet.