Accelerate-stop distance available (ASDA)
The length of the take-off run available plus the length of stopway, if such stopway is declared available by the appropriate Authority and is capable of bearing the mass of the aeroplane under the prevailing operating conditions.
Contaminated runway
A runway is considered to be contaminated when more than 25% of the runway surface area (whether in isolated areas or not) within the required length and width being used is covered by the following:
- surface water more than 3 mm (0.125 in) deep, or by slush, or loose snow, equivalent to more than 3 mm (0.125 in) of water;
- snow which has been compressed into a solid mass which resists further compression and will hold together or break into lumps if picked up (compacted snow); or
- ice, including wet ice.
Dry runway
A dry runway is one which is neither wet nor contaminated, and includes those paved runways which have been specially prepared with grooves or porous pavement and maintained to retain “effectively dry” braking action even when moisture is present.
Landing distance available (LDA)
The length of the runway which is declared available by the appropriate Authority and suitable for the ground run of an aeroplane landing.
Maximum approved passenger seating configuration
The maximum passenger seating capacity of an individual aeroplane, excluding pilot seats or flight deck seats and cabin crew seats as applicable, used by the operator, approved by the Authority and specified in the Operations Manual.
Take-off distance available (TODA)
The length of the take-off run available plus the length of the clearway available.
Take-off mass
The take-off mass of the aeroplane shall be taken to be its mass, including everything and everyone carried at the commencement of the take-off run.
Take-off run available (TORA)
The length of runway which is declared available by the appropriate Authority and suitable for the ground run of an aeroplane taking off.
Wet runway
A runway is considered wet when the runway surface is covered with water, or equivalent, less than specified in subparagraph Contaminated runway, or when there is sufficient moisture on the runway surface to cause it to appear reflective, but without significant areas of standing water.