Onboard Weight & Balance Systems

[Brian Abraham]

I understand the 744F comes standard with the Honeywell system, which is also certified for the MD-11. Various Airbus aircraft have been certified with a WBS as well, but seems to be little used (if at all) because of (I'm guessing here) the system complexity and associated maintenance costs.

Who of you use a WBS and what is your experience and what type of aircraft? Is it used as a primary source of information, or as a check of conventionally generated data?

One gentleman notes in another thread that the Vickers Merchantman had a very robust and reliable onboard WBS system.

I raise the question mainly out of the recent 100 tonne error in the EK407 accident at Melbourne, previous SQ event at Aukland, and MK at Halifax.

Many thanks.

[onehotflyer]

We use ours just for a gross error check when entering the figures. Have to investigate if there is more than 2% difference. Some places where they put tail stands in can cause a bit of a problem with the info on the odd occassion.
We still calculate our own V speeds. I believe that BA uses the speeds that the systems gives them although they must have some way of cross checking it. Not sure. System would have been good in the MK case. Dont know if its fitted on any 200s.

[theloady]

when i was on the 747 classic Oceanarlines,i used to perform weight&balance on the manual form only...
No WBS system on board.

During the last time..we had a laptop on board with a good Jeppesen stand-alone prog. called Powerloader..nice and easy to use when you have standard cargo...


rgds

[Flightwatch]

I used the system on the B744F for 8 years. It is not particularly accurate and can suffer errors from ground slope etc. However the great thing about it is that it shows in small font on the FMS what it thinks your TOW and ZFW weight is so that when you manually enter the final figures you can instantly see if there is a gross error. On all except one a/c it was a dual system.

We had to investigate if the figure was more than +/- 5,000Kg different from the loadsheet so we would certainly have picked up a 100t error. It was also particularly useful to see how loading was progressing and estimating when the aircraft would be ready for departure. It was sometimes necessary to move the a/c to check it i.e. after push back.

[411A]

Onboard?
The STAN system was certificated over thirty years ago...STAN (Sum Total And Nose) was quite accurate, provided however it was maintained properly.

Hello, are we listening...maintained properly, was the key.
For those operators that used the STAN system...pleased.
For those that could not maintain it properly, disappointed.

No surprise there.:}

[Willit Run]

Our Company uses a non boeing W&B program, and another non Boeing performance program.
When i get the flight plan, and W&B final, I take a SWAG at what the V2 speed should be. If there is a big error somewhere, that usually makes me look closer at what has been handed to me., But, we also have one person reading the WTs to the captain as he enters the numbers, so we always have 2 sets of eyes looking at the data.
Just S L O W down a little!