A preliminary NTSB report released Thursday says Marine One twice attempted to send takeoff warnings to Ronald Reagan Washington National Airport air traffic control earlier this month but the warnings did not go through, and the helicopter subsequently came within 0.82 miles (1.32 km) of an airliner during the airliner’s takeoff. That distance breached federal aviation rules requiring 1.5-mile separation; the White House and aviation officials said the president was never in danger. NTSB descri

A preliminary NTSB report released Thursday says Marine One twice attempted to send takeoff warnings to Ronald Reagan Washington National Airport air traffic control earlier this month but the warnings did not go through, and the helicopter subsequently came within 0.82 miles (1.32 km) of an airliner during the airliner’s takeoff. That distance breached federal aviation rules requiring 1.5-mile separation; the White House and aviation officials said the president was never in danger. NTSB described the incident as a separation failure.