July 30, 2007

NTSB cited human error in both '05 helicopter crashes

In June 2005, two helicopters crashed into the East River just three days apart, causing serious injuries to some of the crew and passengers. The final reports from the National Transportation Safety Board -- which have been out for sometime but didn't get much attention -- both blame human error at least in part.

The probable cause of the June 14 crash, a sightseeing flight operated by Helicopter Flight Services from the Wall Street Heliport, was listed as "The pilot's inadequate preflight planning, which resulted in an attempted takeoff with an overweight helicopter, and subsequent impact with a pier and water. Factors were a high ambient temperature and unfavorable winds."

In the June 17 crash, a Corporate Aviation Services charter at the 34th Street heliport carrying executives from MBNA Bank, the NTSB report cites the probable cause as "An inadvertent encounter with a left quartering tailwind. Factors in the accident were settling with power, the high gross weight of the helicopter, and the crew's failure to accurately assess the winds in the area."

After the 34th Street crash, the pilot was among those hospitalized. His account, as quoted in the NTSB report is especially dramatic:

At 25 to 30 feet above the water, about the time of the right pedal turn, the helicopter began to "sink." The pilot noticed an audible "degrading" of the rotor rpm, but did not crosscheck the engine instruments or the rotor tachometer. "It felt like we were losing power and we were starting to sink. I didn't know if we had enough power to fly away, and I couldn't land back due to crowding [on the helipad]."

As the helicopter descended, the pilot maneuvered it toward the western bank. The helicopter shuddered during the descent, as the pilot adjusted the flight controls to cushion for a water landing. He attempted to deploy the landing gear floats, but was "too late," and the helicopter sank.

Following the water landing, the pilot was unable to locate the cockpit door handle, or to open the door on his side after the helicopter submerged. Unable to open his door, and running short of breath, the pilot released his seatbelt and swam towards light until reaching the surface, adding he had "no idea" on how he exited the cockpit.

And from the co-pilot's account of the same crash:

According to the copilot, he then announced "Floats! Floats! Floats!" but waited for the pilot to acknowledge and give the order for the deployment. The pilot did not immediately reply. At water contact, the pilot announced, "Blow the floats!"

After the helicopter submerged, the copilot could not find the door "unlock switch," and never searched for the emergency release handle. Instead, he broke the window out of the copilot's door, cutting his hand. He then released his seatbelt, and swam through the broken window to the surface.

The copilot swam back under the water to search the helicopter for trapped occupants, but he could not gain access to the cockpit or cabin. The copilot resurfaced, and a head count revealed all of the occupants were on top of the water.

The passengers described their exit through the right cabin door. Many remembered who opened the door and the order in which the passengers exited the helicopter. One passenger said, "I was looking for a door, [passenger name] grabbed me by the collar and pulled me up. I saw light and exited the helicopter. I believe I was the last out..."

The passengers were asked if they were familiar with the emergency evacuation procedures for the helicopter. Responses to the question included "Some," "Somewhat," and "No." Only one of the six passengers said that he was familiar with the procedures.

The helicopter did not gain altitude as it neared the end of the heliport, so the pilot executed a turn to the right in an attempt to clear the tailrotor from the pier, but the tailrotor struck the edge of the pier as the helicopter descended. The helicopter then impacted the water, the pilot deployed the floats, and the helicopter rolled quickly inverted.

July 30, 2007 04:24 PM in Sightsology, Tours, Transportology

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