AIR India Express ‘Vande Bharat’ Flight IX 1134 evacuating stranded Indians from Dubai to India, tragically crashed in rainy conditions on August 7, 2020 evening at Calicut International Airport in Karipur near Kozhikode, Kerala. The Boeing 737 NG aircraft overshot what is termed a ‘tabletop’ runway, went through the airport boundary wall, tipped over the edge to drop over 35 feet, and broke into three pieces, two large and one smaller, with the front portion damaged the most and having most of the deaths. At the time of writing, 18 persons including the pilot and co-pilot had died, and around 149 out of the total 190 passengers and crew with injuries were admitted in 13 hospitals in Kozhikode and nearby towns, with 53 having been released.
Tabletop runways are those constructed in hilly regions or plateaus, cutting and leveling the hilly terrain, and creating a flat surface of relatively small area with steep drops on all sides. Such runways are considered more risky, especially in conditions of high winds or fog, rain or snow which may impair visibility and cause slippery conditions on the surface, increasing the chances of the aircraft reaching either end or the side edges and dropping off. India has six airports with such tabletop runways, namely at Calicut, Mangalore, Kullu, Shimla, Pakyong (near Gangtok Sikkim), and Lengpui (near Aizawl, Mizoram).
The media has been full of speculation about possible causes of the crash, behavior of the pilots, and stories about inadequacies at Calicut Airport, some right and many wrong. One senior safety expert who was part of the inquiry team into the horrible 2010 crash at the tabletop Mangalore airport which killed over 150 people, even went so far as to proclaim that the Calicut air crash was “not an accident but an act of murder” by the airport authorities, DGCA and MoCA, who had failed to implement the many safety measures recommended after the Mangalore crash.
So first let us look at the facts, at what is known and what is not, then at how the inquiry is being conducted, and finally at long-term measures required to minimise or prevent similar accidents at Calicut and other Indian airports with tabletop runways.
It is known that the pilots had first attempted to land from the landside at Runway 28, having received information from Air Traffic Control (ATC) on visibility, rainfall and winds. However, at around 1900 ft altitude, the pilots decided to abort the landing and go around, for reasons not yet known, indicating poor runway conditions they had observed. The aircraft rising to around 7000 ft over the sea, then attempted landing from the seaside, that is, from the other end of the runway, designated Runway 10. This approach is known to be riskier, with a downward slope, and at this time with a tailwind to boot. The aircraft landed way beyond the safe touchdown point, which is 1000ft from the start of the runway, at around 3000ft, could not brake sufficiently due to the wet runway conditions and perhaps higher speed as well, then crashing through the boundary wall and falling over the edge.
Again, reason for this option taken by the pilots is not known yet. What transpired inside the cockpit between the pilots, between them and Air Traffic Control (ATC), and other pertinent information will be known from the FDR and CVR data. Important questions will be: did ATC warn the aircraft about its excess height on approach, and perhaps on its speed too? Was the Category-I Instrument Landing System (ILS) at Runway 10 functioning properly, and how did the pilots respond to ILS signals? Was the safe landing zone clearly marked on the runway? Did the runway have properly functioning centre lights, some experts having questioned that? Knowing they were landing way down the runway, why did the pilots not initiate another go-around like they did the first time? Were the pilots fatigued and stressed, as noted by several pilots on Vande Bharat flights with their long flight-times without rest?
AIRPORT SAFETY INFRASTRUCTURE
Contrary to many press reports, Calicut Airport’s runway was not short, and had indeed been extended in 2017 to 2,860 metres (9,300 feet) to permit landing of wide-bodied aircraft, which had not been allowed since 2015 due to safety concerns with the then shorter runway. The RESA (runway end safety areas) on both ends had also been increased to 240m from the earlier 90m, shortening the runway, since additional land was not available for expansion. (However, AAIB and the wider Inquiry Committee should also ascertain the construction and materials of the RESA and ensure that all RESAs in Indian airports fully conform to ICAO specifications on soft RESA to assist in slowing down overshooting aircraft.) Nevertheless, Calicut Airport today ranks 11th among airports in India by air traffic, and wide-bodied Boeing 777s and even 747 jumbo jets have been landing safely there since then. After DGCA sharply warned AAI-Calicut in 2017, runway friction has supposedly been regularly monitored and a machine for removal of dangerous rubber residue from the runway was also, although only recently, acquired. So AAI-Calicut and DGCA which was to ensure implementation both say they had indeed acted on all the recommendations after the Mangalore crash, but only between 2017 and 2019, a good six-eight years later. Only luck saw no crashes during this period. The accident inquiry will hopefully check and pronounce on these safety measures.
The Air Accidents Investigation Board (AAIB) has started its investigations, and taken possession of the vital black box or Digital Flight Data Recorder (DFDR) and the cockpit voice recorder (CVR) which were recovered intact from the crash. It may be recalled that AAIB was set up in 2012, after much pressure and advocacy by safety experts, aviation commentators including this writer, and by international organisations such as the International Civil Aviation Organisation (ICAO), so as to bring about separation of accident inquiries from the aviation regulator responsible for aircraft and airport certification and inspection, namely the Directorate General of Civil Aviation (DGCA), which earlier also used to conduct accident investigations in an obvious conflict of interests. AAIB is tasked to conduct independent investigations, prepare a preliminary accident report, and assist in setting up a larger independent Committee of Inquiry by experts. The fact that the DG, AAIB, group Captain Aurobindo Handa, was personally present at Calicut soon after the crash, and took possession of the CVR and FDR, are good signs.
However, there are many signs of continuing, unwarranted and dangerous interference by other agencies. According to press reports, a parallel inquiry has been ordered by the DGCA, who has been making a series of remarks with the appearance of conclusions on the accident. Union minister for civil aviation (MoCA), Hardeep Puri, too has been sharing some of his wisdom on the crash with the media, while simultaneously appealing to all concerned not to speculate, but to await the results of the Investigation. Airports Authority of India (AAI) too, which runs Calicut International Airport, has been releasing statements as to the “complete adequacy” of safety measures, with appreciative echoes from DGCA and MoCA both of whom are responsible for oversight of these.
Each of these government agencies was clearly covering its own backside, and all of them have not so subtly been engaged in building a narrative blaming the pilots who, unfortunately, cannot defend themselves. The Indian Commercial Pilots Association (ICPA) has voiced its alarm at such attempts. The FDR and CVR, along with downloaded data from Boeing, will undoubtedly reveal much more about the crash and various factors contributing to it.
The public and other stakeholders should exercise vigilance to ensure that the AAIB is allowed to conduct a truly independent investigation, and not be pressurised by MoCA, DGCA and AAI. The minister has no excuse for making pronouncements pre-judging the inquiry. And it is shocking that DGCA, who is amazingly a non-technical IAS officer as per the baneful practice of governance in India, too is continually demonstrating his supposed superiority. It is high time this practice changes. Would India tolerate a generalist administrator heading the department of atomic energy or the department of space?
LONG TERM SOLUTIONS
First, an important recommendation after the 2010 Mangalore crash was to provide Engineered Materials Arrestor Systems (EMAS) at both ends of the runway. EMAS are layers of crushable concrete and other materials, which absorb the energy of aircraft after it overshoots, quickly slowing it down to a stop with minimum damage to aircraft, passengers or cargo. EMAS should ideally be around 120-180m. EMAS are already in place in most military airports in India. They are mandatory in US airports, with the Federal Aviation Administration (FAA) even paying for many of them, and ICAO is expected to soon release global advisories for the same. It is learnt that AAI Calicut has so far declined to install EMAS due to high initial and maintenance costs. The minister too has gone on record saying EMAS is unnecessary. Detailed studies in the US and EU have shown EMAS to have high cost-benefits when weighed against possible accidents. Should cost really be a factor when weighed against loss of life and aircraft? Expeditious action should be taken to install EMAS at least at all tabletop runways in India. Hopefully, the inquiry will underscore the necessity of EMAS at Calicut and all other table-top runways in India.
Second, the issue of additional runway length at Calicut Airport as recommended, currently stuck due to resistance of local residents, should also be addressed by AAI with assistance of the Kerala government. Sharing of costs between different central and state agencies should be explored. That runway length is indeed a safety factor is reinforced by the fact that after the Calicut crash, all wide-bodied aircraft have been directed to other airports in Kerala.
Third, another less-addressed problem in tabletop runways is that the terrain is such that vehicle movement is easy at the airport itself, but very poor below the table. In Karipur too, while local people were the first to reach the crashed aircraft and start rescue work, a few airport fire tenders and rescue personnel came next and did a sterling job, while local fire engines and others came much later. Access roads should be built quickly to enable fire and rescue teams to reach the airport periphery. Other emergency response measures should also be reviewed.
Fourth, DGCA should frame and issue new guidelines to ATCs and airlines regarding landing conditions at all tabletop runways in India during rainy conditions, along the lines of fog warnings. In the present instance, if such guidelines had been in place, good alternative airports were available very close by at Kannur and Cochi, and the aircraft could have been diverted there.
Actual safety ought to be the guiding and deciding factor henceforth, not airport or airline viability, political pressure or protecting vested interests. It is hoped the AAIB will be up to the task and be truly independent guardians of civil aviation safety.