The FAA and the Park Service have taken some steps to implement the National Parks Air Tour Management Act, but nearly six years after its passage, “the required air-tour management plans have not been completed,” according to a new report from the Government Accountability Office. Therefore, “it is unclear how some of the act’s key requirements will be addressed, such as creating incentives for air-tour operators to adopt quiet-aircraft technology.” In addition, the slow implementation has limited the ability of air-tour operators to make other major decisions, “such as expanding or selling their business.” Meanwhile, the level of implementation to date, the GAO said, “has had little effect [on noise] on the parks.” Operators have been unable to increase their number of air tours beyond their pre-2000 levels or expand to additional parks.