Adds more details on restriction

By David Shepardson

WASHINGTON, March 14 (Reuters) - The Federal Aviation Administration said on Friday it is imposing permanent restrictions on non-essential helicopter operations around Washington's Reagan National Airport and eliminating helicopter and passenger jet mixed traffic.

The FAA is permanently closing one key route and evaluating alternative helicopter routes after the National Transportation Safety Board this week made two urgent safety recommendations following the January 29 mid-air collision of an American Airlines AAL.O regional jet and an Army helicopter that killed 67 people.

The FAA will also prohibit use of two smaller runways at the airport when helicopters conducting urgent missions are operating near the airport.

In the aftermath of the crash, the FAA temporarily barred most helicopters near the airport - located in Arlington, Virginia - until it could review the NTSB's initial findings.

The NTSB cited the "intolerable risk" of collisions and noted that helicopters transiting near the airport at the maximum authorized altitude of 200 feet could have only about 75 feet of vertical separation from an airplane on landing approach.

Since 2011, there were 85 recorded events involving a potentially dangerous near miss between a helicopter and plane - a lateral separation less than 1,500 feet and vertical separation less than 200 feet, the NTSB said.

Senate Commerce Committee Chair Ted Cruz is holding a March 27 hearing on the incident that will include the NTSB and FAA. "The data was there and we should have seen action to prevent this," Cruz said, calling the 85 incidents "very disturbing."

Airlines for America, a group representing American Airlines and other U.S. carriers, last week urged the FAA to permanently reduce helicopter traffic around the airport. The group called on the FAA to suspend some nearby helicopter routes with limited exceptions for essential military or medical emergencies.

The FAA also said it will limit the use of visual separation to certain Coast Guard, Marine and Park Police helicopter operations outside the restricted airspace.

The FAA is conducting an assessment of helicopter traffic near airports including Boston, New York, Baltimore-Washington, Detroit, Chicago, Dallas, Houston and Los Angeles and the U.S. Gulf Coast.

(Reporting by David Shepardson; Editing by Andrea Ricci)

((David.Shepardson@thomsonreuters.com; 2028988324;))