New Delhi: One of the six table-top runways in the country, the Kozhikode airport in Kerala, where an Air India Express flight crashed on Friday, is among the most risky in the country to land on. As the name suggests, it is an airport where the runway sits on top of a plateau and has a steep precipice dropping into a gorge at both ends as well as on the sides.In the Kozhikode accident, it is important to note that the aircraft tried to make a landing during heavy rain and overshot the runway and fell around 35 feet down the slope. The impact caused it to split and resulted in loss of 18 lives and injuries to many.Last fatal commercial flight crash too was at a table-top airportThe last fatal crash of a commercial flight in India had also taken place at a table-top airport – in Mangalore, Karnataka in 2010. That mishap had taken 158 lives and at that time too, the aircraft was an Air India Express jet.Apart from these two airports, the other four airports that have table-top runways in India are Lengpui in Mizoram, Kullu and Shimla in Himachal Pradesh, and Pakyong in Sikkim. However, out of these, commercial flights operate only out of Lengpui.Such table-top airports are constructed in hilly areas where there is a paucity of plain land. Hill tops are levelled to create a plain top to provide for the landing strip. However, since there are physical limits to how much a mountain top can be levelled, often these landing strips have deep gorges all around and leave no scope for overshooting the runway.Though in the case of Kozhikode, the gorge began nearly 240 feet from the edge of the runway, the aircraft overshot the runway and for some reason was not able to come to a halt before the drop, leading to casualties.Panel said that chances of planes overshooting or undershooting runways remained highFollowing the 2010 crash, a court of enquiry was constituted to investigate the crash. The probe was led by former Air Marshal B.N. Gokhale, who recorded in his report that flight operations on such table-top airports require a high level of skill and caution.While referring to how the probability of “undershooting” or “overshooting” remained high at such airports, the report had recorded how “there are three tabletop airports in India from where scheduled flights operate. These are Mangalore, Kozhikode and Lengpui”.On the conditions at these airports, it noted that “because of the undulating terrain and constraints of space, these airfields require extra skill and caution while carrying out flight operations. The hazard of undershooting and overshooting, in particular, can lead to grave situations, as was the case in this accident. These table-top runways also have a problem of access roads around the airfield, which may need to be used in case of aircraft accidents.”In the case of Kozhikoke airport, the report had noted that “while the length of the runway 24/06 is adequate for operations by aircraft such as Airbus A320 and Boeing 737-800, the downward slope at end of R/W 24 leading into hill slope is not recommended if one is to consider the hazards of overshooting the paved surface during takeoff or landing.”Airport authorities ignored warnings, recommendations to install safety devicesFollowing the Mangalore mishap, a member of the Civil Aviation Safety Advisory Council had also written in 2011 to senior bureaucrats about how Kozhikode runway lacked adequate safety mechanism, especially in wet conditions.In his note, Mohan Ranganathan had written that all flights landing at Kozhikode “in tailwind condition in rain are endangering the lives of all on board”. He had cautioned: “It is a dangerous situation, especially in wet conditions.”In view of the precarious situations, many operators had stopped flying the bigger Airbus A330 and Boeing 777 into Kozhikode airport.Though over the past decade two recommendations were also made to install a ground arrestor systems at all table-top runways, it was ignored citing high operational and maintenance costs. One of these recommendations were made after a Bombardier Q-400 plane with 75 people on board had veered off the same runway at Kozhikode in 2017, also when the runway was wet. However, the airport authorities did not deem it necessary to install the safety equipment, which could have possibly prevented the Friday accident.