Experiment Moved Noise, But Didn't Eliminate It

When people living in Folsom (CA) complained about noise from aircraft taking off and landing at Mather Airport each night, local aviation officials were quick to react. The Sacramento County Airport System shifted traffic away from Folsom and sent it south, over Cameron Park, Shingle Springs and El Dorado Hills.

That didn't work.

Instead of reducing noise, SCAS officials said it simply moved the din from one area to another.

The Sacramento Bee reports, during the experiment, VFR pilots flying to and from Mather were asked to fly the alternate routes between 10:00 pm and 7:00 am. IFR flights were exempted from the request. By the end of the testing period, both the SCAS and the FAA had received more than 1,400 noise complaints by phone and mail.

"Here in Folsom, I don't think there was much of a change," resident Bill Bryant told the Bee. "I felt it was just as noisy."

From a ground-bound perspective, the noise is expected to increase. Military aircraft from nearby Travis AFB will be based there during runway construction at the base.

What's the solution? It could be the "continuous descent approach" (CDA). Under that concept, arriving aircraft begin descending about 10 miles from the threshold, maintaining a steady three-degree down-angle. That way, aircraft avoid periods of long flight at level altitudes. People on the ground don't hear the constant throttling-up of aircraft coming out of their descent and, oh-by-the-way, it saves on fuel.

The practice is being hailed in Europe, where new EU limitations on both noise and air pollution have caused big headaches for both commercial and private aircraft operators. UPS, which operates nighttime flights from Mather, says it will switch to the new CDA procedures later this year.

FMI: www.matherfield.com/airport.htm, CDA Procedure Explanation