From the Flight Deck features insights from the core of our aviation family – our pilots! This issue, learn more about runway declared distances with Mike Kopp, Jet Linx Director of Operations and longtime pilot.
A runway is defined as a leveled strip of smooth ground along which aircraft takeoff and land, but what constitutes a suitable runway is determined based on numerous factors. Those include the type of surface orientation to terrain, slope, and what are known as declared distances – Take Off Distance Available (TODA), Take Off Run Available (TORA), Accelerated Stop Distance Available (ASDA), and Landing Distance Available (LDA).
TODA is the total distance available for the takeoff, from the beginning of the takeoff run to a point where the aircraft is at 35 feet above the ground. This distance may include a clearway that is not a paved surface. TORA is the distance available from the beginning of the ground roll to lift off. ASDA is the distance from brake release available to accelerate to takeoff speed and then abort the takeoff and stop on the runway, if necessary. This distance may include a stop-way, a level surface only designed for safe overruns on aborted takeoffs or long landings. LDA is the distance from the threshold available for landing.
For the same runway, these distances may all be the same or may be different. It is the Captain’s responsibility to be familiar with the declared distances on each runway they intend to use, and make the appropriate calculations to determine whether the runway is suitable for the intended operation. Aircraft weight, elevation, temperature and runway contaminants such as rain, snow or ice must all be accounted for.
Operators develop Runway Analysis (RA) programs for departures to include the takeoff analysis and a Destination Airport Analysis Program (DAAP) for landing calculation. To further operational safety and runway knowledge, pilots receive annual aircraft specific training addressing individual aircraft type performance, and annual company training covering the company procedures for RA and DAAP.