History of Flight
On October 4, 2011, at about 1525 eastern daylight time, a Bell 206B helicopter, registration N63Q, crashed into the East River shortly after taking off from East 34th Street Heliport (6N5) in New York, New York. The commercial pilot and one passenger were not injured, one passenger sustained serious injuries, and two passengers were fatally injured. The helicopter was substantially damaged. The flight was conducted under 14 Code of Federal Regulations Part 91 as a personal sightseeing flight for visiting friends. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated at about 1524 and was scheduled to return to the heliport.
The pilot, seated in the right cockpit seat, reported completing the before-takeoff checklist. He brought the helicopter to a hover, made a right pedal turn, and attempted to depart into the wind. After climbing to an estimated altitude of 30 to 50 feet above the East River, he felt a small left yaw and applied right anti-torque pedal. He then heard what he thought was the engine-out audio warning and believed an engine failure had occurred. In response, he initiated a hard right turn back to the heliport and lowered the collective. Observing that the engine N1 speed was high, he concluded the initial yaw was weathervaning rather than an engine malfunction. He increased collective pitch intending a normal landing, but the helicopter began an uncommanded yaw to the right. The yaw rate rapidly increased into a spin around the main rotor mast that could not be stopped with full left pedal input. The pilot believed the helicopter had experienced a tail rotor drive train failure or loss of tail rotor effectiveness (LTE). He lowered the collective and raised it just before water contact to cushion the impact. The helicopter entered the water and rolled inverted.
A passenger in the left cockpit seat reported that the helicopter moved backward as it lifted off, with the nose pointed down. The helicopter then moved erratically, banked, and began oscillating side to side before striking the water and rolling inverted. He did not recall hearing any audible warnings.
A lineman at the heliport stated that the four passengers arrived about 30 minutes before the helicopter. Heliport personnel did not provide a passenger briefing. The helicopter arrived at about 1517, landed on pad 4, and continued running. The lineman escorted the passengers and assisted with seatbelts while the helicopter was running. The helicopter took off rearward, climbed to about a 60-foot hover over the river, turned left parallel to the shoreline, and started forward. The nose then dipped, and the helicopter spun left one and a half turns out of control before colliding with the river.
Witnesses reported that the pilot did not shut down the engine or exit before takeoff. They observed the helicopter lift off, back up over the river, and rotate around the main rotor mast several times before impact. The engine sounded normal, and no smoke was seen before impact.
Personnel Information
The pilot, age 56, held a commercial pilot certificate with rotorcraft-helicopter, airplane single-engine land, and airplane multiengine land ratings. He recorded 2,287 total flight hours, including 1,482 hours in rotorcraft and 805 hours in airplanes, with 420 hours in the Bell 206. In the 90 days before the accident, he logged 5.1 hours in the Bell 206 and 4.6 hours in multiengine airplanes. In the 30 days before the accident, he logged 1.7 hours in the Bell 206 and 2.7 hours in multiengine airplanes.
On April 21, 2011, the pilot failed an initial commercial pilot check ride in a Robinson R44. The designated pilot examiner noted on the Notice of Disapproval that reexamination would cover takeoff, landing, and go-arounds. On April 25, 2011, the pilot successfully completed a reexamination that included oral and flight portions. The examiner stated in a postaccident interview that LTE and tail rotor malfunctions were covered during the oral examination.
Aircraft Information
The helicopter was a single-engine, two-bladed, five-seat Bell 206B, serial number 2063, built in 1976 and registered to the pilot on January 29, 2007. It was powered by an Allison 250-C20 turboshaft engine rated at 400 shaft horsepower. The most recent annual inspection was completed two days before the accident on October 2, 2011, at an airframe total time of about 11,581 hours. No outstanding discrepancies were listed in the maintenance records.
Meteorological Information
No weather recording capabilities were available at 6N5. The pilot did not check weather before the flight. The closest observation, from Central Park in Manhattan about 2.2 nautical miles north, reported at 1551: wind variable at 4 knots, visibility 10 miles, ceiling 5,000 feet broken, temperature 17°C, dew point 11°C, altimeter 30.01 inches of mercury. At LaGuardia Airport about 5 nautical miles northeast, the observation at 1551 reported wind from 330° at 9 knots gusting to 17 knots, visibility 10 miles, scattered clouds at 3,500 feet, ceiling 7,000 feet broken, temperature 17°C, dew point 9°C, altimeter 29.98 inches of mercury.
Wreckage and Impact Information
The helicopter impacted the East River near 6N5 and came to rest in about 35 feet of water. It was recovered that evening and transported to the New York Police Department Aviation Unit at Floyd Bennett Field. Examination found no evidence of preimpact failures or malfunctions of the engine, transmission, drive train, main rotor, tail rotor, flight controls, or structure. There was no indication of an in-flight fire.
One main rotor blade remained attached, bent opposite the direction of rotation, consistent with water contact. The other blade exhibited a chordwise fracture at the outboard doubler consistent with bending overload; the outboard section was not recovered. The main transmission rotated freely with no metallic sounds. The tail rotor driveshaft was intact except for the forward section, which showed torsion overstress fracture features consistent with sudden stoppage from tail rotor impact with water. No fatigue or preexisting anomalies were found. The engine showed no anomalies; all components functioned normally in subsequent testing.
Medical and Pathological Information
Toxicology testing on a urine specimen from the pilot was negative for ethanol and drugs. Two passengers died as a result of the accident: one from drowning at the scene, and one from complications of near-drowning on October 11, 2011. A third passenger died from complications of near-drowning on November 6, 2011; because this death occurred 33 days after the accident, the report lists this passenger as having sustained serious injuries under the regulatory definition. The manner of death for all three was listed as accident.
Tests and Research
Fuel samples from the helicopter and the fuel truck met specifications. Water content in the fuel filter bowl was 42 ppm, and in the truck sample was 54 ppm; no limit for water in jet fuel exists. Weight and balance calculations estimated the helicopter's takeoff weight at 3,228 pounds using the most recent empty weight from 2008, which exceeded the manufacturer's maximum allowable gross weight of 3,200 pounds. Postaccident weighing with residual water gave an empty weight of 2,146.8 pounds, resulting in a calculated takeoff weight of 3,461.2 pounds. The pilot reported he calculated a total load of 1,131 pounds, but a front-seat passenger stated the pilot did not ask for weights or perform calculations before takeoff.
The FAA Advisory Circular 90-95 describes loss of tail rotor effectiveness as a critical low-speed aerodynamic characteristic that can cause an uncommanded rapid yaw rate. Contributing factors include high gross weight, low airspeed, and right downwind turns.