The disruption which crippled Heathrow and other UK airports in the summer cost BA Â£100m, the carrier has revealed. The figure is more than double its original estimate of Â£40m.
But despite the loss, BA said it had made a pre-tax profit of £176m for the second quarter ending September 30.
The airline also announced that it was disposing of its loss making regional service BA Connect to low cost carrier Flybe.
At the height of the security alert after the UK police uncovered an alleged terrorist plot, BA cancelled 1,280 flights over an eight day period in mid-August.
Willie Walsh, BA's ceo, said that despite the "significant impact of the security disruptions", the results were "good" and that in the "extremely difficult operational environment", revenue improved.
BA said it made an operating profit for the three months of £134m after a Â£106m write-down of BA Connect.
Revenue was up by 4.9% to £2,313m compared with £2,205m for the same period in 2005 but fuel costs also rose, by 30.2%, to £534m.
The decision to sell the regional operation of the loss-making BA Connect comes just ten months after it changed its name from BA CitiExpress and embarked on what BA called a "major drive" to improve profitability and compete more aggressively in the UK regions.
BA will retain the operations from London City Airport and the Manchester-New York route and also its ground handling company British Airways Regional Limited.
Under the deal, BA will take a 15% stake in Flybe, formerly British European.
Mr Walsh said the disposal was part of "our continued efforts to improve the profitability of short haul."
He added: "Point to point regional operations are not a strategic part of our business and we believe that such activities are better undertaken by a regional low cost airline.
"Despite the best efforts of the entire team at BA Connect, we do not see any prospect of profitability in its current form."