Commercial, Regulatory

NTSB: ‘Series of Missteps’ Led to Hudson Midair

By By Andrew Parker, Managing Editor | October 1, 2010

Animation shows cockpit view from the Piper PA-32R-300 one second before it struck the Eurocopter AS350BA on Aug. 8, 2009 over the Hudson River. NTSB Image

The National Transportation Safety Board (NTSB) has released its findings in the Aug. 8, 2009 midair collision involving a helicopter and a small aircraft over the Hudson River near New York City. Nine people died in the crash, which involved a Liberty Helicopters-operated Eurocopter AS350BA and a privately flown Piper PA-32R-300. NTSB’s multi-faceted probable cause puts blame on pilot situational awareness, the limitations of the “see-and-avoid” concept and a Teterboro Airport (TEB) controller being distracted by a personal cell phone call, while also identifying a number of contributing factors.

“This collision could have been prevented. But a series of missteps—including controllers distracted from their duties and pilots who failed to maintain situational awareness—overrode the safety benefits achieved through technology in the tower and in the cockpit,” NTSB Chairman Deborah Hersman said following a five-hour public meeting on Sept. 14. The hearing featured presentations from Bob Gretz, investigator-in-charge, as well as remarks concerning aircraft performance and air traffic control. “While traffic alerts go a long way in helping pilots ‘see and avoid’ other aircraft, these technologies are not, in and of themselves, enough to keep us safe. Strong operating procedures, professionalism, and commitment to the task at hand—these are all essential to safety,” Hersman added.


According to Gretz, the TEB controller divided his attention between a personal phone conversation and work duties. The pilot of the Piper had read back the incorrect frequency to the controller, and the collision happened four seconds after the TEB controller hung up his cell phone.

NTSB also determined that both pilots did not sufficiently employ the data from their electronic traffic advisory systems. Other contributing factors were FAA procedures regarding transfer of communication between ATC facilities—in this case, between TEB and Newark Intl Airport (EWR)—and FAA regulations that failed to provide enough vertical separation in Hudson River Class B airspace. Two months after the accident, FAA created an “exclusionary zone” to separate helicopters and seaplanes from aircraft flying over the river, and implemented several new rules for the heavily trafficked corridor. NTSB issued five new “urgent” safety recommendations in its report, including redefining the boundaries of the East River CTAF, revising FAR 93.392, updating Advisory Circular 90-48C and developing standards for traffic advisory systems in helicopters. For the full list of recommendations and to view NTSB’s report, visit

Receive the latest rotorcraft news right to your inbox