NTSB probing aborted landings at Reagan National Airport prompted by nearby Army helicopter

(CNN) — The National Transportation Safety Board is investigating the aborted landings of two commercial flights approaching Reagan National Airport on Thursday as a US Army Black Hawk helicopter was approaching the Pentagon nearby.
Helicopters near the airport have been under intense scrutiny since the January 29 midair collision of American Airlines Flight 5342 and an Army helicopter from the same unit. The crash killed 67 people.
The Federal Aviation Administration, which is also invest