“Well, there’s also a helicopter route that goes right down the river that’s at or below 200 feet. And so you’ve got intersecting routes that are apparently de-conflicted by, you know, only several hundred feet — which is not a lot of room for a margin of error.”
What’s more, Federal Aviation Administration rules allow pilots a standard 75-foot deviation from the prescribed altitudes, which could potentially drop that margin even lower, Brauchle said.
“Hypothetically … that’s a 150-foot difference,” he said.
“If there’s only initially going to be about a 200-foot separation, that gets the [airplane and helicopter] within 50 feet of each other.”