'ASDA' refers to 'Accelerate/Stop Distance Available'.
It's different in the two directions because 06 has a 150m reduced width starter extension (to enable a minimum TORA of 2,000m in both directions) but being reduced width it cannot be included in the ASDA or LDA for 24.
As originally envisaged, the third runway at Heathrow was originally to be only about 2,000m to just cater for domestic flights so Farnborough's runway would have been an ideal alternative but Heathrow's proposed new runway has apparently now been upgraded to be similar in dimensions to the other 2 runways.
Last edited by chevvron; 4th October 2019 at 11:34.