WASHINGTON — A helicopter firm hired by the U.S. Forest Service to haul firefighters intentionally falsified records, an action that led directly to a crash two years ago on a California mountainside that killed nine people, federal accident investigators said Tuesday.
Carson Helicopters has acknowledged that it claimed its helicopters could lift far more than they were actually capable of, said investigators for the National Transportation Safety Board.
The NTSB investigation into the crash Aug. 5, 2008, found a troubling "failure of the federal oversight authorities," said Debbie Hersman, head of the safety board.
The Forest Service never bothered to verify that Carson's helicopters were capable of what the company claimed, even though other helicopter firms told investigators that the company's claims were suspicious.
"Firefighters are emergency responders," Hersman said. "They are trained to work in extremely dangerous situations, and they must be able to trust the system that supports them. This accident represents a failure of that system."
The helicopter, which was thousands of pounds heavier than it should have been, labored and could not gain altitude as it lifted off from a remote ridge near Weaverville, Calif., struck trees and crashed on its side. Nine of the 13 people aboard died, and the others, who escaped before flames engulfed the chopper, were seriously injured.
The NTSB will decide the cause of the crash later Tuesday. In preliminary presentations, investigators said an analysis of the Sikorsky S-61N helicopter showed that its engines were barely able to lift it off the ground — and that the craft was well above the safe weight for takeoff.
The helicopter was 1,437 pounds heavier than the pilots realized because Carson used false weight information for the craft, investigators said.
The takeoff was even more precarious because the firm had cut and pasted false information about the performance of the helicopter's two turbine engines into the pilots' manuals, according to the inquiry.
As a result, the helicopter was more than 3,000 pounds heavier than it should have been for a safe takeoff, including the required safety margins, investigators found.
In fact, the helicopter should not have taken on any passengers. It weighed 16,895 pounds with only the pilots and a Forest Service inspector aboard, which was already above the maximum allowable takeoff weight of 15,840, the NTSB said.
"In summary, the helicopter was too heavy to take off," said Zoe Keliher, an NTSB investigator.
The NTSB is likely to explore the oversight of government-operated flights.
The FAA regulates civilian aviation but is not allowed under federal law to oversee government flights. It had limited oversight authority over Carson because the company also operated flights for private businesses.