Sitting in a Piper Archer II on the ramp at Northern Virginia’s Manassas Regional Airport/Harry P. Davis Field (KHEF) on a sunny June afternoon, Paul Diffenderfer had some excellent intel on the instrument flight rules (IFR) clearance the tower controller was about to read to him. That’s because Diffenderfer, a principal air traffic management (ATM) advisor with The MITRE Corp., had just received an email with all the ingredients of his expected clearance — down to the ...


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