The recent crash of Air India Express Plane which was carrying 191 people at the Kozhikode airport has pointed out how risky tabletop runways can be. Constructed on elevated terrains and mostly having little space for last minute manoeuvre, tabletop runways at times pose challenges for pilots while landing aircraft. Many flight crashes have taken place due to a tabletop runway as landing can be extremely tricky and challenging for pilots.
In India at least five airports, including at Kozhikode where an Air India Express aircraft crashed have tabletop runways. The four tabletop runways operated by Airports Authority of India (AAI) are Kozhikode, Mangalore (Karnataka), Shimla (Himachal Pradesh) and Pakyong (Sikkim). The fifth Lengpui airport in Mizoram is with the state government.
Tabletop runways are constructed on hilly or elevated terrains. Also, there could be low lying areas adjacent to such runways and there could be gorges at the end of such runways.
The Kozhikode airport has a tabletop runway on top of a plateau. The runway has a steep precipice that drops into a gorge on both sides and ends. The structure is believed to have caused the crashing of an Air India Express plane as there was no margin for overshooting the runway. The plane went down the slope till around 35 feet and the impact was such that the plane was halved causing deaths of many.
A senior Air India pilot said that automation might not help in the case of tabletop runways. There is also the issue of optical illusion, where the runway might seem to be nearer whereas it would actually be further away, he added. The pilot also stressed that there is not much buffer zone unlike normal runways.
There are tabletop runways in different parts of the world and only when the runway length is less, there could be issues with landing of aircraft. In the case of Kozhikode airport, the runway is about 9,000 feet which is quite long, according to a senior regulatory.
However, the report said that it is a possibility that the plane could have touched down at a higher speed than usual which gave less time to the pilot to bring it to halt. In fact, when the plane landed, it was raining heavily.