Aug. 9, 2009 -- Pilots who fly low over the Hudson River off New York City mostly agree the area is one of the nation's most congested and dangerous airways, and may need new rules. But they say the corridor should remain open despite the fatal collision of a small plane and tour helicopter that killed nine people Saturday.
The aircraft were operating in an area over the river that is outside the supervision of air traffic controllers, where aircraft below 1,100 feet operate on a "see and be seen" basis and are required to avoid each other. Planes flying at higher altitudes are under the supervision of air traffic controllers in Newark, N.J.
The area "is what I call the major leagues of aviation; you don't play there if you're not proficient," said Bob Miller, who runs a Buffalo, N.Y.-area flight school called Bob Miller Flight Training. Miller said he has done training with his students into the corridor, but only when he believed they were ready.
Planes flying south under 1,100 feet, as was the plane that collided with a tour helicopter Saturday, are instructed to fly along the New Jersey side of the Hudson River, while those flying north use a lane on the New York side.
But some say that may not be enough. There have been calls to ban certain types of traffic in the area -- or at least to regulate it more tightly.
"After all the information is gathered on this event and others, that maybe we will have to take a step back and look at the traffic flow here so that we can protect families our communities," N.J. Gov. John Corzine said.
The National Transportation Safety Board (NTSB) is on the scene to investigate the crash and indicated it would look closely at the rules.
"We are going to be looking very closely at air traffic control tapes, radar data and any requirements or obligations that either pilots had with respect to maintaining particular altitudes or locations," NTSB chairwoman Deborah Hersman told ABC News' "Good Morning America." "All of that will be part of our investigation."
Miller said flying through the corridor may mean encountering 12 to 14 other aircraft per trip. So, he added, it might be worth requiring all pilots to file detailed flight plans to fly through the corridor, or separating the altitude windows for airplanes and helicopters, as is done in other areas such as Niagara Falls.
"It can be pretty scary going north and south at 1,100 feet with helicopters crossing the river," Miller said.
"It is extremely safe if everybody is competent and knows what they're doing," he added. "If you're not looking and watching, you might run into something."
Justin Green, a private pilot and aviation lawyer with the firm Kreindler & Kreindler, said the area is so congested because of "funneling an unlimited number of aircraft" into a tight space that he stopped using it. He has called for closing the corridor to private sightseeing planes but agreed that it should remain open to others.
"You put enough planes in an airspace, you will have a collision like this," he said. "You don't have an accident every day, but these folks didn't have to die. You can still have the airspace open, but impose rules so this doesn't have to happen."
But J.P. Tristani, a retired airline pilot and former Marine, disputed the degree of danger involved in flying over the Hudson. He thinks the key is having assurances that pilots who go into the area know the rules and are aware of what they have to do.
"Where is the data that supports that this area is dangerous?" he asked. "It is an area that requires pilots to be aware. … It is a caution area that requires pilots to be attentive and do the job they are supposed to do."
ABC News' Aaron Katersky contributed to this report.