Less than 24 hours since the tragic crash of the Air India Express flight on Friday evening in Kerala’s Kozhikode, the death toll has risen to 19. The Vande Bharat repatriation flight — for those affected by the coronavirus pandemic overseas — was carrying 190 passengers from the Dubai International Airport. According to flight radar data, faced with inclement weather and tailwind (wind blowing in the same direction as the course of movement), the inbound aircraft struggled to land in its first two attempts.
According to the Airports Authority of India (AAI), the plane finally touched down at a taxiway located about 1,000 metres from the start of the 2,700-metre-long runway. However, faced with poor visibility, the aircraft overshot Runway 10 at the Calicut International Airport (also known as Karipur Airport). The plane plunged off the tabletop runway and split into two as it crashed 30 feet below into a gorge.
So what is a tabletop runway?
A tabletop runway, unlike most runways on flat plains, is located atop a raised landform, like a hill or a plateau. While they offer a picturesque view of the landscape that necessitates such a runway, aviation experts have pointed out that landing planes on these runways requires skill and precision. This is, in part, because of the optical illusion created by the tabletop runway. For the pilot in the cockpit, the runway would appear to extend away into the distance, often masking from view the very real danger of overshooting the cliff ahead.
This phenomenon was also recounted to The Hindu by an international airline pilot in 2010, shortly after the crash landing of the Air India Express Flight 812 in Mangaluru.
Airports with tabletop runways are expected to prepare for landing eventualities with mechanisms such as arresting beds or Engineered Materials Arresting System (EMAS) that will act to resist a potentially uncontrolled aircraft, even up to 80 miles per hour.
There are three tabletop runways in India — at the Mangalore International Airport in Karnataka, the Calicut International Airport in Kerala, and at the Lengpui Airport in Aizawl, Mizoram.
At the Lengpui Airport, for example, a Category I Instrument Landing System (ILS) is present for the pilot to land safely during low visibility conditions. According to the AAI, ILS offers descent guidance for the aircraft ‘under normal or adverse weather conditions’.
After the horrific Mangalore Airport crash which claimed 158 lives in May 2010, it was alleged that the pilot who had overshot the runway by 1,600 metres had not only ignored the advice of the First Officer to ‘go around’, but had also fallen asleep for most of the flight’s duration. The resultant fire also contributed to the death of all but eight passengers who managed to survive.
Unfortunately, for the Boeing 737-800 aircraft which also faced low visibility on account of the rains in Kozhikode on Friday, the landing overshot the runway, albeit any fire which could have worsened the situation.