Design flaws reported in helicopter model

LIHUE — Mechanical issues with the model of helicopter that crashed into a cliff near the Napali Coast last week have raised concerns among federal air traffic safety officials for over a decade.

Federal Aviation Administration and National Transportation Safety Board officials have addressed mechanical flaws inherent in the design of the aircraft in numerous reports since at least 2008, when the NTSB issued a safety recommendation, concluding that the hydraulic system powering rotors in Eurocopter AS350 model helicopters was prone to excessive wear, which “increases the possibility of a serious accident.”

Last year, the Federal Aviation Administration issued an “airworthiness directive” regarding several helicopters in the AS350 series, including the specific model involved in last week’s crash.

In the directive, FAA officials spelled out new further requirements for inspecting tail rotors and pitch rods in the helicopters and concluded that an “unsafe condition exists and is likely to exist or develop on other helicopters of these same type designs” and could result in mechanical failures “and subsequent loss of control of the helicopter.”

AS350 series helicopters have been involved in 18 fatal crashes since 2010, according to the NTSB’s aviation accident database.

An NTSB spokesperson said Monday that a team of investigators will examine the fatal helicopter crash from three different angles, looking at potential causes linked to factors caused by human error, mechanical failure and the surrounding environment at the time of the accident.