Altiport

Altiports are generally characterized by having a runway with an atypical slope to fit in the local topography.

Ultimately, this slope helps aircraft decelerating when landing and assists acceleration during takeoff.

According to International Civil Aviation Organization (ICAO) Document 9150: STOLport Manual: "An altiport may be defined as a small airport in a mountainous area with a steep gradient runway, used for landing up the slope and for take-off down the slope, thereby making use of only one approach/departure area.

"[2] According to the former French Technical Instruction on Civil Aerodromes (ITAC) of 2000, an altiport is specifically designed for serving mountainous regions.

An altisurface is defined as a graded area that is not an aerodrome but that can be used as a steep runway with a single approach / departure path.