The Australian Transport Safety Bureau (ATSB) has released its preliminary report regarding the take-off of an Airbus A340-500 flown by Emirates that nearly turned into a disaster.

http://www.atsb.gov.au/publications/inv ... Prelim.pdf http://xrl.us/bescyd

The pilots used a laptop to develop the flight plan which involved a reduced-power take-off. The performance calculation used to determine the power settings required on the engines were based on an incorrect value. The weight of the aircraft was entered as 262 tonnes instead of 362 tonnes. Neither the pilot nor the co-pilot caught the error during cross checks,

More info can be found here:
http://catless.ncl.ac.uk/go/risks/25/67/1