N71MC
2009-AUG-08 · Hudson River, near Hoboken, New Jersey

Multi-aircraft Event — Private N71MC / Liberty Helicopter Tours N401LH

A Piper PA-32R-300 and a Eurocopter AS350BA tour helicopter collided in mid-air at approximately 1,100 feet over the Hudson River, resulting in the deaths of all nine people on board both aircraft. The collision occurred in a high-traffic VFR corridor where pilots were responsible for their own separation under the see-and-avoid concept. The investigation revealed that the Teterboro air traffic controller was distracted by a personal phone call, which led to his failure to correct the Piper pilot's incorrect radio frequency readback and his failure to provide timely traffic advisories. The Piper pilot, having failed to contact the next controller, was not receiving traffic alerts, while the helicopter pilot's visibility was limited by the aircraft's structure and the busy urban backdrop.

Aircraft 1
Private — Flight N71MC
Piper PA-32R-300 Cherokee Lance · N71MC
Teterboro Airport (TEB)Ocean City Municipal Airport (26N)
Souls 3 · Fatal 3
Aircraft 2
Liberty Helicopter Tours — Flight N401LH
Eurocopter AS350BA · N401LH
West 30th Street Heliport (JRA)Sightseeing Tour
Souls 6 · Fatal 6
Phase
Cause
Total Souls
9
Total Fatalities
9
Report

Investigation Summary

The accident occurred within the Hudson River VFR corridor, a narrow slice of uncontrolled airspace beneath the Class B airspace of Newark Liberty International Airport. The Piper pilot, Steven Altman, departed Teterboro at 11:49 a.m. and elected to fly 'down the river.' During the handoff to Newark, Altman read back the frequency 127.8 MHz instead of the correct 127.85 MHz. The Teterboro controller, who was engaged in a personal phone call at the time, did not catch or correct this error. Consequently, Altman never established contact with Newark and was not receiving radar flight following or traffic advisories during his transit of the busy corridor. Meanwhile, the Liberty Helicopters Eurocopter, piloted by Jeremy Clark and carrying five Italian tourists, departed the West 30th Street Heliport at 11:52 a.m., climbing south-southeast. The Piper was approaching from behind and slightly above the helicopter. A pilot on the ground at the heliport witnessed the impending collision and attempted to broadcast a warning on the common frequency, but neither aircraft responded. At 11:53:14 a.m., the Piper's left wing struck the helicopter's main rotor mast, severing the wing and the rotor blades. Both aircraft fell immediately into the river. The NTSB emphasized that the 'see-and-avoid' principle is inherently limited in high-density areas where aircraft can be camouflaged against complex city backgrounds.

Final Conclusions

The NTSB determined the probable cause was the inherent limitations of the see-and-avoid concept and the Teterboro controller's distraction due to a personal phone call. The distraction prevented the controller from correcting the pilot's frequency error and providing traffic alerts. Contributing to the accident were both pilots' ineffective use of available electronic traffic information (Traffic Advisory Systems) to maintain awareness, ineffective FAA oversight and procedures for communication transfers in the Hudson River Class B exclusion area, and FAA regulations that failed to provide adequate vertical separation for aircraft in the corridor.

Video Analysis

No video analysis linked for this case file yet.

Crew Experience

Liberty Helicopter Tours N401LH — Eurocopter AS350BA · N401LH

Pilot

Total hours
2,700

Jeremy Clark, Liberty Helicopter Tours pilot.

Systems & Failure Modes

i

See-and-Avoid

The primary method of collision avoidance in VFR flight, which the NTSB noted is limited by human physiological factors and cockpit visibility obstructions.

i

VFR Corridor

A specific volume of airspace where aircraft can fly without an ATC clearance, provided they remain within defined horizontal and vertical boundaries.

i

Conflict Alert

An automated function of the ATC radar system that alerts controllers to predicted separations below minimums; in this case, the alert was not acted upon.

Interesting Facts

  • 01The collision occurred at an altitude of approximately 1,100 feet.
  • 02The Teterboro controller was on a personal phone call for several minutes leading up to the collision.
  • 03The Piper pilot incorrectly read back the Newark frequency as 127.8 instead of 127.85.
  • 04A radar conflict alert occurred in both Newark and Teterboro towers, but was not noticed by controllers.
  • 05The NYC medical examiner's office attributed the deaths of recovered victims to blunt trauma.
  • 06The FAA established the 'Hudson Rule' (Special Flight Rules Area) three months after the accident.

Safety Actions & Advisories

Establishment of Hudson River SFRA

The FAA created a Special Flight Rules Area (SFRA) requiring pilots to use specific radio frequencies, maintain speeds below 140 knots, and complete mandatory training.

Vertical Separation

New rules required helicopters to operate at lower altitudes (below 1,000 feet) than fixed-wing aircraft (1,000–1,300 feet) within the corridor to reduce collision risk.

ATC Protocol Changes

The NTSB recommended and the FAA implemented stricter policies regarding personal phone use and distractions in air traffic control towers.

Known Controversies & Unanswered Questions

NATCA Party Status Removal

Reference ↗

The NTSB removed the National Air Traffic Controllers Association (NATCA) as a party to the investigation after the union issued a press release disputing the NTSB's preliminary findings regarding the controller's role.

Location

Hudson River, near Hoboken, New Jersey · 40.7422, -74.0225

Case File History

  1. Final reportUpdated final conclusions.

Related Cases

Case ID · hudson-river-mid-air-2009Last updated · Filed

© 2026 TechBridge Software Co., Ltd. — BlackBoxWiki is an open aviation reference. Not affiliated with any aviation authority.