AMT Seth Reeves and the rest of Coast Guard Rescue 6553 navigated dangerous weather en route to the Guadalupe River, where they saved hundreds of campers.
The destroyer Fitzgerald had a "safe and professional interaction" with an Iranian helicopter while operating in international waters, the official said.
Controllers lost contact on May 1 because a temporary control tower antenna had not been set up at the correct location, Brig. Gen. Matthew Braman told AP.
The National Transportation and Safety Board is recommending helicopters no longer fly along the route when planes are landing on specific runways at DCA.