When every foggy day sends flight schedules for a toss, relaxing take-off norms might seem like the perfect answer to the woes of passengers and airlines. But a few civil aviation experts say the move is fraught with risk.
“The problem with lowering the minimum visibility is that even aircraft that are equipped to operate in CAT I and II Instrument Landing System (ILS) conditions can take off in low visibility but in case the aircraft develops a snag and has to come back, it cannot land in such low visibility,” said a senior official of an airline on condition of anonymity.
It is easier for an aircraft to take off during dense fog but landing is much tougher. Many private airlines that have the permission to operate in CAT II ILS conditions cannot land in dense fog but can take off. The Directorate General of Civil Aviation (DGCA) is considering relaxing take-off norms from the present minimum visibility of 500 metres to 150 meters of Runway Visibility Range.
Last year, airline operators like Jet Airways, Air India and SpiceJet had forwarded a request to the DGCA to de-link the norms for take-off and landing.
But the arguments against the move are piling up. "De-linking take-off norms from landing is like giving a one-way ticket to heaven. An aircraft that is equipped with just CAT-I or II ILS can take off during dense fog but what would the pilot do if the aircraft develops a technical snag and has to be brought back to the airport?” said an industry source.
But, counters an airline official, "Internationally, norms for take-off are relaxed as chances of an aircraft developing a snag just after take-off are very slim."
There is another reason why the plan might not work: ultimately, it is the pilot who decides whether or not the plane takes off in fog. Many pilots, say experts, will be loath to put so many lives at risk by flying when the option of an emergency landing is blocked out.
Director General of Civil Aviation Kanu Gohain, however, said the concept of Low Take-Off Minima is different from landing. “The two are very different things and are not linked," Gohain said.
"The proposal is still in the initial stage and there are a lot of issues to be thrashed out,” he said.