Operators of private aircraft who have relied on the U.S. Department of Transportation’s Block Aircraft Registration Request (Barr) program to protect privacy “should assume their flights will appear” on Internet flight-tracking displays as the government’s plan to limit the program takes effect today, August 2, general aviation groups advised. NBAA and AOPA are challenging the government action in the U.S. Court of Appeals for the District of Columbia Circuit, supported by the Experimental Aircraft Association. “While we anticipate that the court will reverse the government’s action, we also expect that the Barr program will be curtailed,” said NBAA president and CEO Ed Bolen. “As we wait for our day in court, we strongly encourage everyone who has used the program to ask government officials to preserve their ability to opt out from having their flights tracked.” Aircraft operators who want to opt out of having their flight details disseminated now must apply to the FAA and demonstrate a “valid security concern.” NBAA said existing Barr participants should continue to send the association requests to add or delete tail numbers in anticipation of Barr being reinstated.