NYPD Commissioner Ray Kelly revealed over the weekend that the department had developed the capability to take down a plane, and law enforcement sources tell NBC New York that this would be done by rifle from a helicopter.
NYPD helicopters are operated by a pilot and co-pilot. In an emergency, a third member can be on board with a .50-caliber rifle. The weapon, which would be attached to a sling with a side door open on the chopper, could be used to disable a boat on the water or a small aircraft.
Law enforcement sources say it is not part of the NYPD's plan to use these choppers with rifles to try to intercept a hijacked airliner. The federal government would have the lead role in that scenario.
North American Aerospace Defense Command spokesman James Graybeal said in a statement that states and cities have the right to "execute law enforcement responsibilities," adding that NORAD's focus is on defending the U.S. and Canada from air attack threats.
Law enforcement officials stressed Monday that the NYPD plans are for doomsday scenarios, rather than any sort of standard operational situation.
Kelly told "60 Minutes" for an interview that aired Sunday that as part of creating the NYPD's counterterrorism unit, the department is prepared for all sorts of scenarios.
Those include, he said after he was asked, taking down a plane.
The idea for this added layer of security came amid the post-9/11 terror threat that al-Qaida terrorists would try to use small aircraft or crop dusters to spread chemical or biological weapons in a population center.
As a result, the NYPD came up with a last-resort plan to arm helicopters to stop such a threat if there was no other way to do it.
The Coast Guard and military have helicopters equipped with similar weaponry.
NYPD officers train with the .50-caliber rifles on the ground at ranges and have conducted exercises and training in their choppers at Fort Dix and other bases.