Table Top Runway, AXB 1344(Calicut Aircraft Crash) and Measures that could be taken
So, what is a Table Top Runway and how aircrafts land there?
Table Top Runways are placed on a plateau/hill, this acts just like the plains and helps the pilot on aircraft to create an optical illusion, this, in turn, helps for a precise approach. The making of it is by simply chopping peak or a plateau of carving side mountain. It’s generally located on islands and also for short runways with an upward slope. So, the outcome of it is, they line up with the horizon and edge of the mountain and creates an optical illusion. If the length is misjudged, it can lead to runway overshoot.
A total of 5 TTR runway are in India, being Kannur International Airport, Kerala(3050m,10,007ft) being the highest in runway length and Shimla Airport, Himachal Pradesh(1230m,4035ft). The rest is Calicut International Airport, Mangalore International Airport, Lengpui Airport in ascending order.
About the flight, Air India Express 1344, the landing destination was Calicut also known as Karipur International Airport. It’s the 11th busiest airport in India and 3rd in Kerala. It got its international status in 2nd February 2006 and also is known for TTR. The flight route was from 7th August 2020 from Dubai, United Arab Emirates- Calicut. (2673km). It was a repatriation flight named Vande Bharat Mission for NRI’s Stranded abroad. Two attempts to landing were made. The runway given was 28 by ATC but it was aborted due to heavy rain and limiting tailwind and the second attempt was for Runway 10, clearance was given at 7:37 pm IST, 7:40 was the approach time. Even at 2000m visibility was poor due to heavy rain. Here it overshot the runway due to poor visibility and landed at 3300ft past the taxiway. it had VHF Omnidirectional Range approach and had the Instrument Landing System (ILS) and follows CAT 1. For Category 1, the height of resolution is 200ft. Decision Height is estimated when visual contact is set to place nearing to runway/ go around. Visibility of Runway should be min 1800ft.
In the second attempt, it skidded of the TTR and fell to 35m steep gorge splitting the fuselage into two. Here the captain on board was Wing Commander Captain Deepak Sathe and First Officer, Akhilesh Kumar along with 4 cabin crew members and onboard was 184 passengers, with 21 of total death and more than 100 injured.
To conclude, the background and warnings imposed on Calicut Airport are that, DGCA has called it a critical field ie, only the captain has the authority to land to the airport. On safety advisory one of the Captains called it “Unsafe” back in 2011. There are less in number of buffer zones towards the landing area, the safety area recommended was 240m but it only covered 90m, so the width of the runway was small. It most importantly lacked Engineering Material Arresting System (EMAS), this could have saved the flight if installed. It is an arresting bed to reduce the severity of a runway overshot limiting to 80miles/hr even if Runway End Safety Area (RESA) is less.