Tuesday, November 1, 2011

Helicopters in Mumbai fly half the recommended altitude

The Economic Times :
Helicopters in Mumbai fly too close to the surface for comfort. Against a recommended altitude of 1,000 ft above the tallest building in an area (obstruction level), they fly at 500-700 ft from obstruction level and sometimes come as low as the height of the buildings.

The risk of flying low, say pilots, is that when there is total engine failure, a helicopter cannot be manoeuvred to open spots and risks crashing on populated areas. The 1,000-ft altitude, a recommendation of the International Civil Aviation Organization ( ICAO), is for allowing helicopters a better chance of being manoeuvred to open spaces like parks or even the sea to minimise casualties on the ground.

Pilots say flying altitudes are determined by air-traffic control (ATC), which follows rules set by the Airports Authority of India (AAI). AAI officials say the 1,000-ft altitude cannot be permitted for helicopters because they will then come in the flight path of aeroplanes ascending from or descending to the airport.

How then is the ICAO's recommendation followed in cities like New York and London? "There, all flight operations are under radar monitoring . But in Mumbai, non-scheduled flights (for example, helicopters) are not covered by radar. This makes it impossible to coordinate the movement of helicopters and aeroplanes at the same altitude," said an AAI official.

"In India, the ATC radar cannot track helicopter movements. Countries like the US, Australia and the UK extend radar coverage to both scheduled and non-scheduled flights. ATCs there assign flight levels to both aircraft and helicopters, depending on air traffic. It's high time that Indian aviation monitored small aircraft and helicopters both for internal security and air safety."

ICAO's 1,000-ft recommendation "was made keeping emergency situations in mind" , said a pilot. "Just because it is only a recommendation and not a mandatory rule does not mean that we ignore it. The recommendation is followed in countries around the world."

A pilot said risk was an integral part of flying a helicopter in the Mumbai of present. In the last 10 years, many buildings in the city have come up which are more than 500 ft tall, examples being Antilia (568 ft) and the Imperial "Twin" Towers (833 ft) in Tardeo. Because of this, and particularly when visibility is low, safety solely depends on the pilot's skill and knowledge of terrain. "In times of low visibility, a helicopter pilot can only guess the presence of a building or a hill. Since ATC cannot trace the helicopter on its radar, it cannot warn the pilot about the presence of an obstruction in the path," an AAI official said.

"It was not dangerous to fly so low in the city 10-15 years ago, when there were few tall buildings," said a pilot. "But now that the height limit for buildings has been relaxed to 300 metres (beyond a radius of 9 km from the airport), the obstacles are far too many.

No comments:

Post a Comment