Noise: Muffling the Jet

After years of enduring the ear-splitting shriek of jetliners flying over their homes, residents of communities near airports can at last look forward to quieter skies. By 1971, FAA Associate Administrator Oscar Bakke announced last week, the aviation agency will most likely demand that the engines on some 2,100 existing commercial jets be muffled to reduce their noise to a still unspecified level.

The FAA also announced that noise limits have been established for the forthcoming breed of “jumbo jets” —Boeing’s 747, Lockheed’s L-1011 and McDonnell Douglas’ DC-10. The legal maximum for jumbo noise will be considerably lower than the sound made by large jet engines now in operation; in effect, it will cut in half the noise audible to those on the ground. Under the new limits, the jet noise should be no louder than that heard by a man running a power mower with a four-cycle engine, the FAA promised, and only a quarter to a half as loud as a “typical rock-‘n’-roll band.”

There is one hitch. Although the FAA’s precedent-setting regulations for jumbo jets go into effect on Dec. 1, the Boeing 747s—which in February will become the first (by 21 months) to start flying passenger runs—will be temporarily exempt. Reason: Boeing applied for certification of the 747 one year before the agency began drafting its noise laws and is too far along in production of the jumbos to meet the FAA deadline. Result: no less noise for a while.