Accidents happen.
As the New York Times reports in “Tourist Helicopter and Small Plane Collide Over Hudson River“:
A small private plane carrying three people and a New York tourist helicopter carrying six collided in midair and plunged into the Hudson River off the West Side of Manhattan just after noon on Saturday. At least two people were confirmed dead, the authorities said, and a search was on for the others.
One of the reasons helicopters tend to fly lower than airplanes is to do something that’s drummed into our heads: avoid the flow of fixed wing traffic. This accident is tragic on so many levels, but it would not have occurred if the plane was flying at the altitude it should have been at.
Indeed, this isn’t the first time an airplane and helicopter have collided. On June 18, 1986, a DeHaviland DHC-6 collided with a Bell 206B helicopter over the Grand Canyon, killing 25 people. Both aircraft were conducting tours over the canyon. As a result of this accident, tour routes were established with separate altitudes for airplanes (8,000 feet MSL) and helicopters (7,500 feet MSL) over the Grand Canyon.
There’s some talk that the airplane in the New York City accident today might have been in some distress and perhaps it was losing altitude. Hopefully, investigators will gather information about how it happened. I can understand how the helicopter pilot may not have seen the airplane at his altitude, especially if he had just taken off and was still at low level, just climbing out. A helicopter pilot doesn’t expect to see airplanes at low level. But that’s no excuse to see and avoid other traffic.