The Federal Aviation Administration (FAA) has started the process to adopt international noise standards for single-engine, propeller-driven small airplanes, which make up 12.5 percent of the fleets of Regional Airline Association (RAA) members.

In a proposed rule, the FAA would adopt current technology as the standard for future planes. But, the actual code would impose a three to six decibel reduction over the current rules. The noise limit on the smallest planes would be 70 decibels, rising to 85 decibels for the larger planes. The standard is the same one proposed in 1999 by the International Civil Aviation Organization and already adopted by the European Joint Aviation Authorities. (JAA.)

The FAA is seeking comment until June 10 and hopes to have the final rule in place by October, when the standard takes effect in other nations, said Mehmet Marsan, a specialist with the FAA's Office of Environment and Energy.

While the proposed rule is stricter, Marsan said current production models would meet the standards. The international task force crafting the rule agreed early to rely on available technology to prevent noise levels from increasing. The group decided not to impose tighter standards that would have required the use of new, unproven technology.

The FAA is setting the standard for single-engine planes because the study group determined that the frequent landings and flyovers during flight training were the source of most of the noise complaints. The multi-engine planes were not the problem, the group concluded.

The new standards will not apply to the vintage aircraft now in operation, Marsan said. However, he said, any changes to the engine cannot make it noisier. "If you add a new propeller and it does not increase the noise, then it can be grandfathered and still keep flying," Marsan said.

In addition to curbing the noise level near airports, the major motivation of an international standard is to facilitate airworthiness approvals for the exporting of these aircraft.

The RAAwill not be taking a position on the issue.

Among the early comments on file is a letter from the Santa Cruz Flying Club seeking an exemption for experimental and sport aircraft. "The purpose of the experimental and sport rules is to eliminate much of the testing and regulatory compliance for these low volume of production aircraft," wrote Mark Boyd of the club. "Experimental and sport aircraft makers should not be required to do testing to verify noise levels before receiving airworthiness certificates. The stated intent of the rule is to help U.S. certification come in line with JAA certification for manufactured aircraft. Most JAA countries do not allow experimental aircraft to be certified. If this rule is implemented to include sport and experimental aircraft, tens or hundreds of thousands of decibel tests will be required of the builders. This is an unnecessary burden, and also will prevent exploration of new technologies."

>>Contact: Mehmet Marsan, FAA, (202) 267-7703. Further information is available on the FAA docket at http://www.dms.dot.gov. Case: FAA-2004-17041.<<