The engine failure that caused a helicopter to crash-land in Häna on Dec. 16 occurred during a simulated power loss that was part of a Federal Aviation Administration pilot check flight, according to a preliminary report on the incident.

A Sunshine Helicopters pilot and a Honolulu-based FAA inspector suffered serious injuries when the tour company's Aerospatiale AS-350BA helicopter hit the ground about 1.3 miles southeast of Maui's Häna Airport.

Sunshine Helicopters owner Ross Scott yesterday said the inspector cut back on the fuel throttle to the point where the aircraft's engine shut down, forcing the tour pilot to make a hard landing in a field near Häna Highway. He said the helicopter was damaged beyond repair.

"He improperly simulated an engine failure because it actually caused an engine failure, and did it over an area that was not suitable to have an emergency landing," Scott said.

FAA Western-Pacific Region spokesman Ian Gregor said "it would be irresponsible for anyone to comment on the possible cause" of the crash until the National Transportation Safety Board issues its final report.

The NTSB's preliminary report said the flight left Kahului Airport on a routine, semiannual proficiency check of the Sunshine tour pilot, whose name was not released.

The FAA told a safety board investigator that performance of a simulated loss of engine power during pilot check rides is "an authorized routine procedure used in evaluating the competency of airmen," the report said.

Sunshine Helicopters told the NTSB the actual loss of power coincided with the start of the simulation, as the inspector "retarded" the throttle. The company said the same tour pilot had flown in the same aircraft several hours before the check flight without any indication of mechanical problems.

STILL UNDER STUDY

The cause of the engine failure has not been determined.

The NTSB report said investigators are examining parts of the helicopter and will review FAA policies related to performance of power loss simulations during check flights.

The NTSB also will look at whether the inspector was familiar with the operating parameters of the aircraft, which had undergone extensive modifications known as an "FX conversion" that included installation of a Honeywell engine.

Scott said he thinks not.

"The FAA inspector was not trained in that engine. He wouldn't have done what he did if he had proper training," he said.

Gregor said the FAA is waiting for more information before deciding whether any changes are necessary in how the pilot checks are conducted.

"With every accident investigation, we review applicable regulations and policies to see if they're appropriate and adequate," he said.

"However, we do not yet know the cause of the accident so we have not considered whether to make any changes to the way we conduct proficiency checks. Helicopter pilots practice so-called autorotations all the time without incident."

The FAA inspector, whose name has not been released, is recovering from back and ankle injuries and has not returned to work, Gregor said.

The Sunshine pilot suffered head, foot and back injuries and also has not been able to return to work, according to Scott.