N311RL
BELL 407 - NO SERIES
The commercial pilot reported that he had landed the helicopter on the oil platform about 1 hour before the accident. He noted that the weather conditions were deteriorating west and north of the platform; he then decided to depart the platform, which did not have any weather monitoring systems installed. He had initiated the start sequence when a strong wind gust struck the platform and pushed the helicopter off of the raised helideck into the water. Witness reports corroborated the pilot's account, and two of the witnesses reported that the helicopter blades were turning but had not yet reached flight idle speed. If a weather monitoring system had been available, the pilot might have decided not to depart the platform given the gusting wind conditions.
On June 28, 2015, about 1000 central daylight time, a Bell 407 helicopter, N311RL, was substantially damaged when strong winds blew it over the side of the helideck during engine start on the South Timbalier 127 oil platform in the Gulf of Mexico. The pilot received serious injuries. The helicopter sustained substantial damage to the fuselage. The aircraft was registered to GM Leasing Company LLC, and operated by Rotorcraft Leasing Company LLC, under the provisions of 14 Code of Federal Regulations Part 135 as a passenger flight. Visual meteorological conditions prevailed for the flight, which was not on a flight plan. The flight was originating at the time of the accident for an unconfirmed destination.The pilot reported that he landed on the helideck about one hour prior to the accident. At that time he observed that the helideck was slick due to pressure washing activities that were being performed as a result of a recent fire at the platform. He stated that about 20 minutes prior to the accident that he noticed the weather deteriorating west and northwest of the platform and held a meeting with the passengers. A decision was made to depart the platform. He proceeded to initiate the start sequence for the helicopter, and obtain a flight clearance from company flight operations. A strong gust of wind struck the platform and the helicopter began to slide across the helideck toward the safety skirting. The nose of the helicopter began to rise and then the helicopter fell off of the safety skirting and into the water below. During the mishap, the pilot activated the helicopter floats and the life rafts. He was able to exit the helicopter onto the life raft and was picked up by a nearby boat. A weather report from another oil platform about 28 nautical miles east of the accident site included wind from 250 degrees at 26 knots. The platform where the accident occurred did not have any weather gathering devices installed. Witness reports corroborated the pilot's statement that a strong gust of wind struck the platform resulting in the helicopter sliding off of the helideck. Two of the witnesses reported that the helicopter's main rotors were turning, but were not yet at flight idle speed when the gust of wind struck the platform. At the time of the accident the operator had implemented Enhanced Operational Control Level Two. This is an internal control used when weather conditions dictate more positive control of operations. Since the accident, the operator has amended the procedures for Enhanced Operational Control Level Two to require that pilot's receive permission from Operations before unstrapping the helicopter.
The pilot's lack of awareness of the severity of the gusting winds, which led to the helicopter being pushed off of the oil platform by a wind gust during engine start. Contributing to the accident was the unavailability of a nearby weather monitoring system.
Source: NTSB Aviation Accident Database
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