The restrictions took effect Oct. 1, when the airport’s control tower was notified, according to the airport. The FAA said its safety assessment identified incidents in which aircraft drifted toward other planes departing at the same time on parallel runways. The agency is convening a Safety Risk Management panel and working with the airport and local stakeholders on the concerns.

Centennial’s tower is also blocking touch-and-go maneuvers, a training exercise in which pilots land and take off repeatedly. The airport said the restrictions were imposed by the FAA.

The limits have prompted concern that flight schools and pilots will have fewer options at Centennial, and that training flights could shift to other already-busy general aviation airports along the Front Range. The Aircraft Owners and Pilots Association’s Northwest Mountain Region manager, Brad Schuster, said aviation groups and nearby residents should have more opportunity to weigh in on changes that affect air traffic across the region.

In a letter to flight school operators, airport CEO Mike Fronapfel said the restrictions have had an “immediate and significant effect” on flight training, general aviation activity and businesses that depend on the airport. He said the airport had no specific timeframe for when normal or near-normal operations would resume, and that it was seeking a workable solution while addressing the FAA’s safety concerns.

The FAA said the changes will remain in place during the review. The restrictions affect not only airport operations but also flight schools, instructors, pilots and airport businesses, while the potential effects on nearby airports remain uncertain.