While Civil Aviation Minister Hardeep Singh Puri may be correct in saying that provision of EMAS is not mandatory in a civil aerodrome as per ICAO guidelines, but experts point out that this hasn't stopped countries from using this additional safety feature in their airports.
EMAS stands for Engineered Material Arresting System and 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 brings to a halt an aircraft that has overrun.
ICAO is a UN agency that sets standards for the international aviation industry. While some of its recommendations are mandatory, others are advisory.
"Kozhikode airport is equipped with a Runway End Safety Area (RESA) as per ICAO guidelines on safety. Engineered Material Arrestor System (EMAS) provides safety benefit if less than standard RESA length is available or at Airports where RESA cannot be provided due to constraints," Puri said on Twitter.
The Minister added that both Airports Authority of India and industry regulator DGCA had evaluated the option to install EMAS at Kozhikode and Mangalore airports - tabletops where last two major aviation mishaps have taken place. But the idea was dropped "considering the complexities of post-installation maintenance & issues related with immediate replacement of product."
A Moneycontrol story had highlighted the importance of EMAS and how it could have prevented the tragedies in Mangalore, in 2010, and now in Kozhikode.
One of the reasons airports have hesitated to use EMAS is the high price tag of Rs 100 crore. And also the fact that it has to be completely replaced if an aircraft does overrun the runway, and ploughs into the EMAS.
That's the reason airports opt for runway end safety area, or RESA, which extends from the runway and can be as long as 90m. The RESA helps if the aircraft has overrun or during undershoots.
"Yes, having EMAS is not mandatory, as per ICAO. But that hasn't stopped countries such as the US, Spain, France and Germany to have it. Even in Asia, countries such as China and Saudi Arabia have it," said a senior industry executive, who didn't want to be named.
The US has the maximum number of EMAS installations. As on April 2019, EMAS was installed at 112 runway ends at 68 of the country's airports. There have been multiples instances where an aircraft after having overrun a runway was brought to a halt because of EMAS.
A study by FAA, the aviation regulator in the US, said about 450m of RESA is required to capture 90 percent of the overruns. This is against the ICAO recommendation for airports to have RESA of 240 metres, which was done at Kozhikode airport.
Interestingly, at Kozhikode, the runway was shortened to give away to the RESA.
SKYbrary, an electronic repository on aviation safety and promoted by several organisations, including ICAO, additionally says:
"As such, it may be an alternative to a RESA where the topography precludes the full recommended length of a RESA or it may be used in addition to a full-length RESA where precipitous terrain immediately follows the end of the RESA."
Precipitous terrain is the main risk factor in table-top airports like those in Kozhikode and Mangalore.
The cost factor
Though Puri hasn't specifically commented on the cost of an EMAS, it has been a big factor for airports to hesitate committing to the safety instrument.
Interestingly, a 2016 study by an aviation expert has shown that EMAS actually ends up saving money, in fact, about a billion dollars
The report, by Rob van Eekeren - a pilot turned safety expert, studied 10 runway overruns that needed EMAS to bring the aircraft to a stop. "Mitigating identified “risky runways” through improving the runway infrastructure can be a very cost-effective way to reduce the risk for human injury, loss of life, property and equipment damage," he said.