Piper PA-32R-300 accident at Hoboken, New Jersey, 8 Aug 2009 (N71MC)

Accident narrative

On August 8, 2009, at 1153:14 eastern daylight time, a Piper PA-32R-300 airplane, N71MC, and a Eurocopter AS350BA helicopter, N401LH, collided over the Hudson River near Hoboken, New Jersey. The pilot and two passengers aboard the airplane and the pilot and five passengers aboard the helicopter were killed, and both aircraft received substantial damage from the impact and fell into the Hudson River. Visual meteorological conditions prevailed at the time of the accident.

### The flight

The airplane was conducting a personal flight under 14 Code of Federal Regulations (CFR) Part 91 from Wings Field Airport in Philadelphia, Pennsylvania, to Ocean City Municipal Airport in Ocean City, New Jersey. The flight included a stopover at Teterboro Airport (TEB) in Teterboro, New Jersey, to pick up a passenger. The 60-year-old airplane pilot held a private pilot certificate and had accumulated 1,121 hours of total flight time, with 834 hours in the Piper PA-32.

The helicopter, operated by Liberty Helicopters, was conducting a local sightseeing flight under 14 CFR Parts 135 and 136 from the West 30th Street Heliport (JRA) in New York, New York. The 32-year-old helicopter pilot held a commercial pilot certificate and had accumulated 2,741 hours of total flight time, with 781 hours in the AS350.

### Sequence of events

At 1140:01, the airplane pilot contacted the clearance delivery controller at the TEB air traffic control tower. The pilot advised the controller of his intended en route altitude of 3,500 feet and requested departure clearance and traffic advisories. Because the pilot planned an en route altitude of 3,500 feet, he was required to contact controllers at Newark Liberty International Airport (EWR) for authorization to climb into Class B airspace after the flight was transferred from TEB to EWR. The Hudson River Class B exclusion area, which extended from the surface of the river up to and including 1,100 feet, provided passage below the Class B airspace.

At 1142:21, while the airplane was taxiing, the TEB local controller asked the pilot whether he was requesting visual flight rules (VFR) "down the river" to Ocean City or southwest bound. The pilot replied he would take whichever route was most direct. The controller stated, "okay just…let me know so I know who [to] coordinate [the] handoff with," to which the pilot responded, "I’ll take down the river [that would] be fine."

At 1148:15, the pilot indicated the airplane was ready for departure. The TEB local controller cleared the airplane for takeoff and instructed the pilot to make a left turn to the southeast and maintain 1,100 feet or below. At 1150:02, the controller identified the airplane on his radar display and executed an electronic radar handoff to the EWR Class B airspace controller, but did not transfer radio communications. The controller then advised the airplane pilot of an inbound Bell 407 helicopter. At 1150:17, the controller advised the airplane pilot that the Bell 407 pilot had the airplane in sight. The controller provided no further advisories of known or observed traffic to the airplane pilot.

At 1150:32, the TEB controller initiated a telephone call to airport operations that was unrelated to his work. During the call, at 1151:17, the controller instructed the airplane pilot to start a left turn to join the Hudson River, which the pilot acknowledged.

The accident helicopter departed from JRA at 1152:00 for a planned 12-minute tour. The helicopter climbed westbound across the Hudson River to an altitude of 400 feet, turned to the south to follow the river, and continued to climb to an altitude of 1,100 feet. Because the heliport and most of the tour route were in the Hudson River Class B exclusion area, the helicopter pilot was not required to contact air traffic control and did not do so.

At 1152:19, while still engaged in the nonpertinent telephone call, the TEB controller instructed the airplane pilot to contact the EWR tower on a frequency of 127.85 megahertz. The pilot responded at 1152:20 and stated, "one two seven point eight." This transmission was the last communication between the pilot and air traffic control.

Also at 1152:20, the EWR Class B airspace controller contacted the TEB controller, asking him to transfer communications for the flight and put the airplane on a heading of 220° so the airplane could stay away from other traffic over the Hudson River. At 1152:28, the TEB controller asked the EWR controller to repeat the instruction, which he did. The TEB controller then attempted to contact the airplane pilot at 1152:37 and 1152:48 but received no response.

A Liberty Helicopters pilot who was waiting to depart from JRA stated that the accident helicopter pilot made a position report on the common traffic advisory frequency (CTAF) when the helicopter was over Stevens Institute of Technology in Hoboken. The waiting pilot stated that he saw the airplane approaching the helicopter from behind and to the right, and transmitted a traffic advisory to the accident helicopter pilot on the CTAF. The accident helicopter pilot did not respond to the advisory.

According to radar data, the collision occurred at 1153:14 at an altitude of 1,100 feet. The groundspeed was about 150 knots for the airplane and about 93 knots for the helicopter, with a closure rate of about 70 knots and a collision angle of about 25°. Between 1152:33 and 1153:24, a conflict alert for the accident airplane and the helicopter was generated 11 times to the TEB local controller and the EWR Class B airspace controller, but neither controller recalled seeing or hearing a conflict alert on his radar display during that time.

### What the investigation found

The Board found that both aircraft were properly certified, equipped, and maintained, and the recovered components showed no evidence of any preimpact structural, engine, or system failures. Weather was not a factor, and the Board noted that sun glare would not have interfered with the pilots' ability to detect and track the other aircraft. Toxicological testing of both pilots was negative for drugs and alcohol. Available evidence suggested the airplane pilot was not likely affected by fatigue; it was unknown if the helicopter pilot had obtained sufficient sleep, so no assessment about fatigue could be made for him.

#### Air Traffic Control Performance

The investigation determined that the TEB local controller unnecessarily delayed transferring communications for the accident airplane from TEB to EWR. The electronic radar handoff had been accomplished immediately after departure, and the controller's workload was light. The Board concluded that this delay prevented the EWR controller from turning the airplane away from Hudson River traffic and having the airplane climb directly into Class B airspace.

Because the TEB controller had not yet transferred communications, he remained responsible for providing traffic advisories. At the time the controller issued the frequency change, his radar display showed three other radar targets representing aircraft in the Hudson River Class B exclusion area. The Board concluded that the TEB local controller did not provide continual traffic advisories to the airplane pilot, as required. The Board further concluded that the airplane pilot may have believed no other potential traffic conflicts existed because he had not received additional advisories, though he was still responsible for seeing and avoiding other traffic.

The Board concluded that the TEB local controller's nonpertinent telephone conversations distracted him from his duties. Because of this distraction and other transmissions, the controller did not correct the airplane pilot's read back of the EWR tower frequency. The Board concluded that the airplane pilot's incorrect frequency selection, along with the TEB controller's failure to correct the read back, prevented the EWR controller from issuing instructions to the airplane pilot to climb and turn away from traffic.

The investigation also found that the TEB front line manager had left the air traffic control tower to run a personal errand for 35 minutes during the time of the accident. He did not advise the controllers where he would be or how he could be reached, nor did he delegate his controller-in-charge responsibilities to another qualified controller who was on break. The Board concluded that the front line manager exercised poor judgment and that both his and the local controller's noncompliance with existing procedures demonstrated a lack of professionalism, which increased the opportunity for errors.

#### Aircraft Operations and Airspace

The Board found that the helicopter was in, or had just completed, a climb at an average rate of 900 feet per minute to an altitude of 1,100 feet. According to Liberty Helicopters procedures and its FAA-approved air tour safety plan, the altitude at which its helicopters normally operate when proceeding southbound on the west side of the Hudson River was 1,000 feet. The Board concluded that the helicopter's climb above 1,000 feet was not consistent with company procedures and decreased the vertical separation between the aircraft.

The Board noted that the airplane was in level cruise flight transiting the area, while the helicopter was climbing past its intended cruise altitude and expected to remain in the exclusion area. The Board concluded that current FAA regulations did not provide adequate vertical separation for aircraft operating in the Hudson River special flight rules area because the regulations did not include specific operating altitudes for local aircraft.

Because the airplane pilot had requested traffic advisories, was attempting to contact the EWR tower, and did not anticipate operating in the Hudson River Class B exclusion area, the Board concluded he was not expected or required to monitor CTAF position reports, including those made by the helicopter pilot.

#### Cockpit Visibility and Traffic Systems

An aircraft performance radar and cockpit visibility study determined that the helicopter would have remained a relatively small and stationary object in the airplane's windscreen until about 5 seconds before the collision. The Board concluded that the helicopter would not have been obscured from the airplane pilot's view but would likely have been difficult for him to detect until the final seconds because it would have appeared as a relatively small and stationary object against a complex background of buildings. A video of the collision showed the airplane rolled suddenly to the right in the last second, leading the Board to conclude that the airplane pilot appeared to have started an evasive maneuver immediately before the collision.

The study also determined that the airplane would likely have been in the helicopter pilot's field of view until 32 seconds before the collision, after which time the airplane was above and behind the helicopter and outside of the pilot's field of view.

Both aircraft were equipped with mode S transponders and were capable of receiving the FAA's traffic information service (TIS), which provides an automatic display of radar-derived traffic information in the cockpit. Reconstructed TIS messages indicated that the airplane should have received a traffic alert associated with the helicopter beginning 32 seconds before the collision, and the helicopter should have received a traffic alert associated with the airplane beginning 37 seconds before the collision. The Board concluded that neither pilot effectively used available electronic traffic information to assist in maintaining awareness of nearby aircraft.

### Probable Cause

The National Transportation Safety Board determines that the probable cause of this accident was (1) the inherent limitations of the see-and-avoid concept, which made it difficult for the airplane pilot to see the helicopter until the final seconds before the collision, and (2) the Tete