During pre-flight preparations, both pilots completed a takeoff performance calculation for a takeoff from Runway 21 at Lisbon Airport. In calculating the performance, the crew believed they had selected the shortest runway length available but had, in fact, used the runway full length. The takeoff distance available was 1,395 m less than that used for the performance calculation, and the aircraft became airborne with only 110 m of the runway remaining.
As a result of this and previous, similar incidents, the airport operator renamed part of Taxiway S to have only one intersection on Runway 21 with the letter S. The aircraft operator moved onto a newer software version for performance calculations in December 2019 which gives a pictorial representation of the runway. They also worked with the data supplier to change the menu for intersection selections for Lisbon Airport to eliminate any confusion over which position refers to the full runway length.