Monday, Jun. 07, 1976

Listening Hard

Environmental opponents of the Franco-British Concorde have long maintained that the 1,400-m.p.h. aircraft is simply too loud to use U.S. airports. That argument seemed very fragile early last week as the first commercial flights slipped quietly into Washington's Dulles International Airport. But then, the next day, the environmentalists' case against the Concorde revived with a whoosh. Returning to France, one of the $60 million planes took off with an earsplitting roar that re-ignited debate over the plane's noise levels and seemed sure to reinforce resistance that is now keeping the craft out of New York.

Bird of Prey. The Concorde's arrival was amicable. Traveling light, with just 76 of its 100 passenger seats filled, the British Airways Concorde covered the distance from London to Washington in 3 hr. 52 min. and--after missing a light plane by a scant 400 ft.--slipped into Dulles at noon on Monday. Minutes after the British plane touched down, its drooping nose giving it the look of a giant bird of prey, the Air France Concorde, with 80 passengers aboard, touched down just as smoothly.

The landings, which were watched by thousands of spectators and hailed by airline officials as the beginning of a new era in aviation, pleased the Concorde's friends and confounded its opponents. Federal Aviation Administration officials reported that the planes made less noise than a Boeing 707, one of the largest standard jets in general use. Spectators on the ground below the planes' landing path expressed surprise at finding the sound levels bearable. "I thought it was gorgeous," said a woman living in a nearby trailer park. "It wasn't bad at all. It wasn't worse than the other planes."

The honeymoon, however, proved a short one. Departing a day later, the Air France plane raced down the runway and then lifted off with a deep-throated rumble. One FAA sound meter recorded the plane's noise level at 129 perceived noise decibels; that was 16 decibels more than the loudest Boeing 707 measured that day, and it meant, logarithmically, the Concorde was more than twice as noisy as the 707. There was no decibel reading for the British flight because the pilot, exercising his prerogative to switch runways, made a last-minute decision to take off on a runway not being monitored by sound meters.

Air France sought to justify its plane's loud takeoff by explaining that the pilot was trying to climb unusually fast in an effort to limit noise over populated areas. British officials told an annoyed Secretary of Transport William Coleman, who has allowed the planes to land only on a 16-month trial basis, that their takeoff plans had also been changed for this reason.

These explanations seemed adequate to U.S. officials and residents of the area around Dulles. But they are unlikely to find much support among Concorde opponents elsewhere. Anti-Concorde forces have already persuaded the Port Authority of New York and New Jersey, which controls Kennedy International Airport, to withhold the craft's landing permission pending a six-month evaluation of its noise levels in Washington. The plane's loud departure from Dulles suggests that the delay may be a long one. Though a later departure was considerably quieter, the noise from the first Concorde takeoffs exceeded New York's allowable levels of 112 decibels by 17 decibels.

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