Have to agree with M Rat,
These laptops and their use to compute take off performance in the cockpit under tight time constraints seems to be a consistent weak link and an accident waiting to happen.
Especially with Crews operating similar types with significant gross weight differences.
In the US, most Major Airlines including the one I work for have dedicated 'load planning' departments that compute the take off numbers then data link them to the FMC.
After double checking the numbers for reasonableness we then accept and load them into the FMC.
It's been a pretty good system with the advantage of using a dedicated department of load planning specialists (with double checks of their own) in a spacious environment working with a lot more than a laptop balanced on their knees with a few minutes to push..
It seems a little ironic, that with all of the emphasis on performance in the theoretical examinations for the UK and JAR licences that under that system most of these disastrous take off miscalculations have been made.
