Engineered Material Arresting System is also called an arrester bed. It's a bed of engineered material laid out at the end of the runway, that helps arrest and bring to halt an aircraft that has overrun.
In May 2010, an EMAS could have helped Air India Express flight IX812, landing at Mangalore airport, from rolling down the runway and burst into flames. Of 166 passengers and crew, only eight survived.
This was the first accident involving Air India Express, a unit of India's flag carrier Air India.
Just a little over 10 years later, in similar circumstances, another Air India Express flight - IX1344, overshot the runway in Kozhikode airport, slid down the slope and split into two. The latest official statements say 18 have died, including the two pilots.
An EMAS could have prevented the aircraft from sliding down and could have saved lives at the Kozhikode airport, which like the one in Mangalore, is a table-top and rests on a hill.
The Kozhikode airport could have got one, if the authorities had listened to the recommendations given by a safety advisory committee set up by the Ministry of Civil Aviation, after the 2010 crash.
"We had pushed for it. But that hasn't happened, either in Mangalore or Kozhikode," Mohan Ranganathan, who was one of the members of the advisory committee, told Moneycontrol.
That a similar accident has happened 10 years apart could be a telling comment on the safety standards of the country's aviation industry. "It is the failure of the system," says Yeshwant Shenoy, a lawyer and aviation safety activist. "Just marking the airport as critical or risky is not enough," adds Shenoy, pointing to DGCA's 2011 listing of 11 risky airports in India that included the one in Kozhikode too.
"Many of these measures, also highlighted by International Civil Aviation Organization, are recommendations. But when it comes to a table-top airport, these should be made mandatory," adds Ranganathan.
A table-top runway sits on a hill, with one or both sides dropping to deep gorge. These runways can create an optical illusion to the pilots, making their job risky.
The disaster - Tailwind, rubbers and a wet runway
The Air India Express IX1344, which was one of the repatriation flights operated under the Vande Bharat Mission, had taken off from Dubai on August 7 at 3.40 pm. It was scheduled to land in Kozhikode at 7.40 pm.
The conditions were harsh. The state had been lashed with torrential rain and the Indian Meteorological Department had issued a red alert for three districts, including Kozhikode. Earlier in the day, a landslide in Idukki had claimed 18 lives.
One will have to wait for the preliminary investigation constituted by the government to come out with its report, to understand what exactly happened with the Air India Express flight. But that the two pilots at the cockpit - Captain Deepak Vasant Sathe and first officer Akhilesh Kumar - had to twice abort landing, was signal enough that the circumstances were severe.
"The approach was for runway 28, but the pilots couldn't land. Then they chose to come from the opposite runway 10, which could have had tailwinds," says Amit Singh, an industry veteran and Fellow of London's Royal Aeronautical Society.
The tailwind would have increased the speed of the aircraft, making landing even more difficult on a runway that was wet, and possibly was 'contaminated.' A runway, explains Singh, is contaminated if it has water more than 3mm deep.
Adding to the complexity would be the presence of rubber. Every time an aircraft lands, it leaves behind up to 20 kg of rubber - depending on the plane's make - on the runway. The rubber deposit happens when the wheels touch the ground, the impact also emitting a puff of smoke. Too much of rubber deposit can damage the runway surface, affecting landings.
Singh points out another factor that would have made things difficult for the pilots in a night when visibility was low because of heavy rains. "It was a blackhole approach as the airport doesn't have ground lights," says Singh. A blackhole approach can make pilots think they are higher than they actually are.
All these factors - speed, rubber and water, can reduce the aircraft's capacity to brake. "Especially so if the runway has a slope, like in Kozhikode. Runway 10 is at a height of 315 feet, goes up to 335 and then it goes down. So, tailwinds, high speed, rubber and on a slope, the aircraft ability to brake is compromised," says Singh.
Flight IX1344 overran the runway, went down the slope and split in two by the impact. Captain Sathe reportedly died on the spot. Co-pilot Kumar was severely injured but later succumbed to his injuries.
If only there was an EMAS to stop the aircraft.
The Mangalore crash and the aftermath
Ranganathan points out that some of the safety advisory committee's recommendations were followed at the Mangalore airport. This includes enhancing the runway end safety area (RESA), which extends from the runway and can be as long as 90m. The RESA helps if the aircraft has overrun or during undershoots.
The Mangalore airport also installed a frangible antenna that will break on impact. In 2010, the antenna was mounted on a concrete structure which the ill-fated Air India Express flight struck, adding to the damage.
Interestingly, the airport did have an arrestor bed made of sand, which is however not as effective as an EMAS.
Both, at Mangalore and Kozhikode, the Airports Authority of India and the DGCA are said to have declined the proposal to have an EMAS.
Instead at Kozhikode, a report by The Hindu in June 2018 points out, the RESA was widened to 240 metres from 90 metres , complying with the ICAO recommendations. Though this may have reduced the length of the runway to 2,700 metres from 2,850 metres, security experts say that the length is sufficient for landing and takeoff.
While this would help, the table-top airport also needed an EMAS, something that the Ministry of Civil Aviation had recommended to the DGCA during the Court of Inquiry into the Mangalore crash.
There are global examples to show that EMAS has helped prevent tragedies. Many of the airports in the US for instance have EMAS. In one of the instances where the system came to the rescue, a Boeing 737 aircraft with 117 persons aboard had overrun the runway at California's Bon Hope Airport. Fortunately, the EMAS brought it to a halt. Neither was the aircraft damaged, nor - and more importantly - was any passenger or crew injured.
The cost factor
So why are airports in India against installing the EMAS, despite its life-saving qualities?
It comes down to the cost. A report by The Hindu, again from 2018, sheds more light. It quotes Kozhikode Airport's then Director JT Radhakrishna saying that the EMAS proposal was rejected as it would have entailed high operational and maintenance cost. The director further said that the airport couldn't afford the bill of Rs 100 crore, the cost of an EMAS.
Ranganathan points out that while the technology is expensive, it also needs to be completely replaced after an impact. "It can't be repaired," he says. In other words, every time an EMAS is used, the airport will have to shell out at least Rs 100 crore to get a new one.
While Rs 100 crore is an expensive tag, does it compare to the loss of lives? There are also intangible costs, like the loss of operations at an airport after a crash or even an overrun.
"How does Rs 100 crore compare to the thousands of crores we otherwise spend on erecting statues. What is more important? What stops the government from incentivising airports to buy these life-saving systems," asks a senior industry executive.
Safety experts like Ranganathan and activists like Shenoy have warned that an aviation tragedy is waiting to happen in any of the airports in the country. Just in July 2019, an Air India Express flight veered off the taxiway. Fortunately, there was no damage or injury.But the Air India Express flight IX1344, was not as lucky.