Concerns that a deadly collision could occur at Reagan National Airport had long been building. But attempts to draw attention to potentially dangerous conditions sometimes went unheeded.

Porter Airlines recently announced a new flight between New York City’s Newark International Airport (EWR) and Montréal Trudeau Airport (YUL).

The new Airbus A321XLR can fly further than any other single-aisle plane on the market. It promises to open up new, nonstop, ...