u/Melodic_Initiative44

My work is located on final approach to Philly international. Typically I see dozens of planes landing every day, however, while I was outside I hear the sudden roar of jet engines. I look up expecting to see a 747 when I these two planes which appear to be a couple hundred feet apart from each-other. While the delta plane WAS accelerating to go around I cannot recall another time where I’ve seen two planes fly like this. Are events like this typical in larger airports?