The FAA has proposed continuing hourly caps at New York JFK International and Newark Liberty International airports through 30 October 2010 to address peak season congestion.
Introduced last year, caps limit operations to 81 per hour during peak times at both facilities.
However, the limits will expire on 24 October 2009 without an extension.
The proposal comes after FAA introduced a final congestion management rule last year that featured slot auctioning. A federal court in December issued a stay of the rule after carriers via the Air Transport Association of America (ATA) protested through formal litigation.
FAA has been soliciting comments on a proposal to rescind the final rule and, as a result, the court has suspended the briefing schedule associated with the ATA's lawsuit.
But the agency says "it is now unlikely that the FAA will have an effective final rule" before the caps expire, so it is pursuing the extension.
The agency will accept public comment on the proposed extension for 14 days after the order is issued in the Federal Register.
The order will likely be published in the register on 5 June.
Caps took effect at JFK on 30 March 2008, and limitations took effect at Newark on 20 June 2008.