Mumbai's towering billboards, which hawk everything from the latest Bollywood movies to soda, block out more than some sunlight. They're also a physical hurdle preventing Air India from reaching its potential on what should be one of its most lucrative routes.

The height of billboards near India's financial hub means the Boeing 777-300ER jets the carrier uses for non-stop flights to Newark, New Jersey, near New York City must fly 51 fewer passengers, or 15 per cent below capacity, in order to clear them. That's costing 100 million rupees (NZ$1.9 million) a month in lost revenue, India's junior aviation minister G.M. Siddeshwara told parliament on Monday.

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For Air India, which is surviving on a 300 billion-rupee taxpayer bailout and hasn't made a profit since fiscal 2006, the adjustment means further delays in eliminating losses. The billboards, some as high as a seven-story building, line the main road between Mumbai and the hub in a northwestern suburb.


"This is a very serious issue," said Mohan Ranganathan, a former commercial pilot and aviation safety consultant based in Chennai, India, who added that signs high enough to represent an obstacle to aircraft would "violate" standards imposed by the International Civil Aviation Organization.

The 16-hour non-stop Newark service operated by Air India - the longest such direct flight by an Indian carrier - requires the twin-engine 777s to carry a high fuel load, so any weight savings must come in the form of fewer passengers.

Air India spokesman G.P. Rao and Vaibhav Tiwari, a spokesman for GVK Power & Infrastructure's Mumbai International Airport, didn't respond to calls seeking comment.

United Continental Holdings, the only other carrier to fly nonstop between Mumbai and Newark, uses the smaller 777-200. The billboards don't affect United's operations or capacity, Mary Ryan, a spokeswoman for the Chicago-based carrier, said in an email.

The basic initial cruise altitude for the 777-200ER with General Electric engines is 36,600 feet (11,200 metres), while for the bigger 777-300ER with GE engines, it decreases to 34,100 feet, according to Boeing's website.

On the highway to the airport most of the billboards are located on top of or between residential high-rises. While some of the tallest are to be found 12 kilometres (7 miles) from the hub, in a residential neighbourhood 2 kilometres away at least 15 billboards can be found along a 600-metre road - peddling an eclectic mix of affordable suburban homes, the latest Bollywood movie and deals on domestic flights.

Airports Authority of India, the former monopoly airports operator and a stakeholder in Mumbai airport, acted to remove some billboards after complaints from Air India, according to the minister's statement on Monday.

All but two of a total 15 billboards were removed, minister Siddeshwara told parliament in reply to a lawmaker's question on Tuesday. The two billboards are under litigation, he said.


"As soon as the remaining two hoardings are removed, the load penalty to Air India Mumbai-Newark flight, shall be reduced significantly," the minister said.

- Bloomberg