The uproar over noise from jet aircraft that fly over Calabasas has spread to Topanga Canyon.
Residents contend that jetliners taking off from Los Angeles International Airport for Northern California make intolerable noise as they rumble over the 2,000-home canyon.
The complaints are identical to those made earlier this year by Calabasas residents who live five miles northwest of Topanga Canyon, beneath a takeoff path known to pilots as "Gorman Five."
About 70 commercial airliners use the departure path each day. The aircraft are between 9,000 and 13,000 feet high when they pass over the western edge of the San Fernando Valley after leaving the airport and making a right turn over Santa Monica Bay.
This summer, Calabasas homeowners urged the Federal Aviation Administration to route the jets farther west, over a less-inhabited area of the Santa Monica Mountains.
So far, the FAA has refused, however, saying that sound readings taken several months ago at various locations in Calabasas showed that the noise is an acceptable level.
Topanga residents who have also demanded sound readings near their homes have been rebuffed by the FAA, neighborhood activist Barry S. Glaser said Monday.
Glaser, a member of the board of the Topanga Canyon Town Council, a citizens group, said homeowners are prepared to sue the FAA if officials do not act to reduce the noise.
"We've invited them to a town council meeting to discuss the problem and they haven't responded," Glaser said. "They're claiming the case is closed. Maybe a lawsuit will get their attention."
Richard A. Cox, chief of the FAA's Terminal Radar Approach Control Division in Los Angeles, said Monday he doubts that the Topanga noise is any worse than that in Calabasas.
"Based on that, I see no changes being made on the departures," Cox said.
Cox denied that the FAA is snubbing canyon homeowners by refusing to measure aircraft noise along Topanga Canyon Boulevard and Old Topanga Canyon Road.
Cox said his office has been tied up on sound studies around the Los Angeles Airport, and with investigations into the Cerritos mid-air collision and last week's reported near-miss between a United Airlines jetliner and a Drug Enforcement Agency helicopter.
One Calabasas community leader on Monday questioned Glaser's contention that a lawsuit may be homeowners' best tactic in the noise dispute.
Dennis Washburn of Calabasas, who heads a coalition of 15 residential groups called the Las Virgenes Homeowners Federation, said his organization has had success dealing with the FAA "in a businesslike manner."
"We understand what the FAA is facing," Washburn said. "They are between a rock and a hard place because they would have to adjust every flight path if they changed this one."
Washburn said Calabasas residents have already won a concession with the FAA's acknowledgment that planes are being routed over their homes.
"They believed the aircraft were not even passing over our area when we first started talking," he said. "Now they admit that they go right overhead."