Something to talk about

A Midwest Airlines Boeing 717 passes stringent noise tests at John Wayne Airport in Southern California

BY BILL WASSERZIEHER


In the combined suburban sprawl of California's Los Angeles and Orange counties, some of the toughest community-imposed noise limits are those in effect at John Wayne Airport in Santa Ana.

But Boeing customer Midwest Airlines is about to help quiet things down with introduction of 717 service. The carrier recently conducted tests with a new 717 to show the airplane could meet the stringent noise standards.

Midwest will be joining a dozen other U.S.-based airlines, including American, Delta and United, that operate approximately 300 flights a day—with some 8.4 million passengers annually—in and out of John Wayne Airport. Commuter, cargo and corporate aircraft add to the activity.

Residents in nearby population-dense towns such as Newport Beach, Costa Mesa, Irvine and Santa Ana worry about the noise that comes with service increases at the airport.

"Some neighbors are real 'plane-spotters.' If they see a strange airplane or livery, they call the airport right away to find out what's going on," said Kevin Burnside, Boeing airport noise engineer and the focal for John Wayne.

To begin operations at the facility, Midwest Airlines first had to prove that its new fleet of Boeing 717s, built 20 miles northwest in Long Beach, Calif., could meet the noise standards at the airport. In August, the airline conducted a series of test takeoffs and landings there. The goal was to meet what regulators call Class A noise level criteria, which would permit Midwest to operate the 717s at John Wayne Airport.

There are seven departure noise monitors at John Wayne Airport, and the decibels they record vary by monitor position. The monitors use Single Event Noise Exposure Level (SENEL) as a standard to document noise duration and intensity. Anything above 65 decibels—a level that's generally not as loud as a lawnmower—registers as a SENEL.

To demonstrate that the 717 is one of the quietest commercial jets available in the world today, Midwest pilots performed five takeoffs and landings in a 717 that the airline received just that morning from the Boeing plant in Long Beach.

On all five departures, the plane recorded noise SENELs consistently quieter than the Class A standards. At monitors Nos. 1-3, located closest to the 5,701-foot (1,730-meter) main runway, the 717 averaged levels eight decibels below the permissible standard. By the time it flew over the most distant monitoring station, noise had dropped to 13 decibels below the requirement.

"Monitor 1 is in a golf course, monitor No. 2 is in a vacant lot, monitor 3 is in someone's backyard, and reflective factors such as trees can have an effect. But the 717 more than met the criteria with plenty of margin to the limits," Burnside said. "We were confident the airplane would qualify, but we wanted to see how well our predictions lined up with the measurements on test day."

The final numbers confirmed the estimates and will aid in future 717 noise level predictions.

Initially, Midwest will have two operating slots at Orange County, starting in October, which it will use to launch 717 operations to Kansas City, Mo. These flights also will introduce 717 service to the U.S. West Coast and will expand the Midwest presence in the busy California marketplace.

Passengers flying on 717s out of John Wayne Airport on Midwest will enjoy premium service that includes two-by-two seating, specially designed Recaro leather seats with adjustable headrests and footrests, and the extra leg space afforded by a roomy 88-seat configuration. Travel & Leisure magazine and the Official Airline Guide publication have named Midwest Airlines as the best U.S. domestic carrier in their 2003 ratings.

william.e.wasserzieher@boeing.com