Black Hawk was flying “way too high” -Trump
It is usually, but not always;
Small drones 50’
Helicopters Civl & Mil 200’
Air Force 600’
Civil Fixed Wing 1000’
You can, and in fact most of the time do fly a different altitudes, but those are standard altitudes when you’re on routes when you’re mixing aircraft in and out of airports, exactly like the crash sequence. 200 feet is plenty of room for a helicopter to maneuver and it’s a very comfortable altitude. The only reason to be at 1000 feet is for instrument training or orientation.
Those numbers are just a single example. All along the southern coast the oil field helicopters* fly 500’ inbound and 700’ outbound, fish spotter planes fly at 1000’ near bases or oil fields. Helicopters at these point move locally at 200’
*There are far more Helicopters operating in the south coast mostly Gulf of America

than anywhere in the world… combined. There is a vast cornucopia, a.k.a. “shipload” of them. To keep collisions down there are permanent altitude restriction in/ out/ over bases and Farp’s*
* Ford Arming and Refueling Point