Preliminary noise tests at Cincinnati/Northern Kentucky International Airport show the growth in overnight air traffic has expanded the 65-decibel noise zone farther north and south. It may require airport buyouts or soundproofing at 28 additional houses in Northern Kentucky, mostly along Ky. 8 River Road and Ky. 18 to the south.

The Federal Aviation Administration needs to complete its tests swiftly and let the airport get back to its 10 p.m. shift from day to night flight patterns instead of the 11 p.m. switchover during testing. The tests allow planes to use the two north-south runways more often instead of the west runway, which routes planes over less populated areas. Once final noise reports are in hand, FAA and airport officials should set night flight procedures that balance the growth in night traffic with noise relief for residents on both sides of the Ohio River.

The airport is a top economic engine for this region, but part of the price we pay is the engines that come with it are noisy. Officials should push for quieter planes and night flight patterns sensitive to populated areas. Progress has been made, but the offset is there are more flights.

The number of flights between 10 p.m. and 7 a.m. almost doubled in the last four years, jumping from 178 a night in 1999 to 343 a night in 2003. Air traffic controllers have had trouble avoiding delays.

One reason the FAA eased the start of night flight procedures from 10 p.m. to 11 p.m. during the tests, which began in January, is that about 30 Comair flights arrive and depart during that hour. DHL Worldwide Express, the air cargo company, starts its flights about midnight, with about 48 departures a night. Regional jets like Comair tend to be quieter. Takeoffs tend to be noisier than landings.

Night flight procedures were established by a 1991 legal deal worked out between the airport and two parties on the Ohio side - Delhi Township and the Sisters of Charity. That agreement remains in force. A new north-south runway is being built, but it will be aligned farther west and used mostly for landings.

Buyouts and soundproofing in Kentucky have been costly. Since 1990, the airport has spent $132.5 million to buy, soundproof or help sell 1,108 homes. All the more reason to push for quieter planes and sensitive flight patterns to keep the high-decibel corridors close to the airport.