WASHINGTON (AP) — A firefighting helicopter crash that killed nine people two years ago was caused by deceptions on the part of the company that leased the aircraft to the U.S. Forest Service and a lack of federal safety oversight, the National Transportation Safety Board determined Tuesday.
Carson Helicopters of Grants Pass, Ore., intentionally altered documents to exaggerate the helicopter's performance capabilities in order to win a Forest Service contract, the board said.
Nina Charlson of Eugene, whose son Scott died in the crash, attended Tuesday's hearing. She told KVAL News she was pleased with the thoroughness of the government's investigation, but disappointment by the multiple failures that led to her son's death.
"I was quite surprised at how many holes there were that fed into the crash," Charlson told KVAL News. "It was really shocking."
The NTSB said the Federal Aviation Administration and the Forest Service missed several opportunities to uncover problems with Carson's helicopters.
"This accident had more to do with Carson's actions than the oversight entities' inactions," NTSB chairman Deborah Hersman said. "But the FAA and the Forest Service didn't hold up their end of the deal to oversee Carson's actions."
The accident points to a larger problem of a lack of safety oversight of nonmilitary aircraft operations by federal, state and local government agencies, board members said. FAA has said it doesn't have the authority to oversee the aircraft operations of other agencies.
Government aircraft operations "have no parent and no one wants to be responsible for them," Hersman said.
NTSB has alerted the Department of Transportation's Inspector General that Carson's actions may merit a criminal investigation, Hersman said.
The board's investigation showed the Sikorsky S-61N helicopter weighed 19,008 pounds when pilots tried to take off from a rugged mountaintop clearing near Weaverville, Calif., on Aug. 5, 2008. But the maximum weight to lift off at full power with no margin to spare was 18,445 pounds, they said. If Forest Service guidelines — which include a safety margin — had been followed, the weight shouldn't have exceeded 15,840 pounds, investigators said.
Carson also provided its pilots with procedures for estimating liftoff weight that eroded safety margins, the board said.
Two months after the accident, the FAA office in charge of overseeing Carson received letters from two pilots with knowledge of Carson's operations who expressed concern that the company was miscalculating helicopter weights, investigators said.
Investigators said that if FAA had provided NTSB with that information at the time, it would have helped them figure out sooner that the weight calculations were faulty. FAA was a party to the accident investigation and its inspectors were aware of the investigation, they said.
However, FAA dismissed the allegations and didn't provide the letters to NTSB until about a year later after the investigators made a general request for documents related to the agency's oversight of Carson after the crash, investigators said.
Carson has surrendered its FAA certificate, the agency said in a statement released after the board meeting. The certificate is the equivalent of an operating license. FAA is also working on clarifying its policy on oversight of government aircraft, the statement said.
The Forest Service said in a statement that it is committed to learn from such tragedies and has "aggressively pursued opportunities to improve its operations from the onset of this accident."
Carson Helicopters issued a statement saying it believes the cause of the crash was a loss of power to the No. 2 engine due to the failure of a fuel control unit while the helicopter was taking off. The company added that their own inquiry uncovered a history of problems with the fuel control unit on the Sikorsky S-61N helicopter. | Read the statement
However, NTSB said it didn't find that problem in this accident.
The helicopter was airborne less than a minute when the rotor began to slow, it clipped a tree and fell into the forest. It was carrying firefighters from the front lines of a stubborn wildfire in the Trinity Alps Wilderness.
Seven firefighters, the pilot and a Forest Service safety inspector were killed. The co-pilot and three firefighters were injured. Survivors told the board that they were unable to unbuckle their seatbelts and had to wiggle out of them to escape the downed helicopter before it was consumed in a post-crash fire. They also told the board that they believe some of those who died were still alive after the crash but were unable to escape.
FAA officials have said they don't have the authority to regulate safety of aircraft leased or owned by other federal agencies or state and local government agencies if the aircraft are dedicated exclusively to government operations.
Twenty-three federal agencies, including the Forest Service, operate 1,632 nonmilitary planes and helicopters, according to the General Services Administration. Some are owned and maintained by the government, while others are leased from private companies such as Carson. Hundreds more are operated by state and local governments.
Federal agencies have policies that leased aircraft should come from companies that have been certified by the FAA, according to the GSA. But FAA limits its inspections and oversight to the portions of the leasing companies' operations that don't involve government leases, investigators said.
Part of the reason for that is that FAA has no expertise in many of the kinds of operations that government aircraft are involved in, such as firefighting, investigators said.
Fatal accidents involving government aircraft are commonplace. A 2001 study by the board said there were 341 accidents involving nonmilitary government aircraft between 1993 and 2000.
Among accidents in the last two years:
- A Forest Service plane conducting an aerial survey of tree defoliation in southwestern Pennsylvania in June struck a light post while trying to land near Lock Haven, Pa. The pilot and two Forest Service employees were killed.
- A California Fish and Game Department helicopter surveying deer collided with power lines near Fresno, Calif, in January. The pilot and three passengers were killed.
- Also in January, a U.S. Fish and Wildlife Service helicopter on a repositioning flight crashed northwest of Corvallis, Ore., killing the pilot and a passenger.
- A New Mexico State Police search and rescue helicopter that had just retrieved a lost hiker crashed into a hillside near Santa Fe in June 2009. The pilot and the hiker were killed; a patrolman acting as a spotter was seriously injured.
- Two pilots and a passenger were killed in April 2009 when an air tanker leased by the Forest Service crashed near Stockton, Utah, in rain and fog.
Copyright 2010 The Associated Press.
Carson Helicopters has been an active participant in the NTSB investigation of the Weaverville crash of N612AZ and as such has not commented publicly during the investigation due to regulatory prohibitions. We have a strong commitment to all the people affected by this tragic accident and to current flight operators of the S61 helicopter to understand what caused this accident.
It became apparent to Carson management and other members of the investigation team that there were issues with one of the 36 performance charts and the weight estimate of the aircraft provided by a Carson employee for performance of the Forest Service contract. Carson forthrightly acknowledged these issues that were the actions of one manager who acted without the knowledge or consent of Carson senior management and is not reflective of Carson's 50 years of dedicated flight operations, 30 years of firefighting and exemplary safety record.
It is Carson's firm contention that the facts clearly show that the primary cause of this accident was a loss of power to the #2 engine of the aircraft. There is a strong chain of physical evidence in the Public Docket that indicates a high probability that a malfunctioning fuel control unit (FCU) caused a sudden loss of power as the aircraft transitioned to forward flight. Extensive independent real-world flight testing has confirmed that even at weights exceeding what the NTSB has attributed to the accident aircraft, N612AZ should have had enough power to fly away from H44 with two properly operating engines. The co-pilot has confirmed much of this evidence with his recent testimony. The two pilots had nearly 26,000 flight hours of cumulative experience, and the copilot is an experienced ex-military Blackhawk pilot and B52 aircrewman. The NTSB has ignored his testimony in favor of supposition. Carson has repeatedly provided to the NTSB substantial evidence that the actual weight of N612AZ was several hundred pounds less than the NTSB has theorized.
Unfortunately, early in this investigation the NTSB lost custody of several fuel control parts, and conducted a filter inspection incorrectly, which they have acknowledged. Since that time, the NTSB has chosen to ignore the physical evidence and flight parameters that indicate a possible blockage in the FCU. They repeatedly refused to participate in independent flight testing, and they have not given proper consideration to the copilot's direct testimony of conditions and available power just prior to the crash.
Carson has discovered there is a history of contamination and FCU power loss issues in the S61 Helicopter that was known by other parties. We regard this as an ongoing safety of flight issue and continue to pursue the source of the problem even as the body of evidence has grown indicating that a partial power loss was the major contributing factor to the loss of the crew and passengers of N612AZ. We continue to extend our thoughts and prayers to the families and loved ones of everyone involved.
The following points can be verified in the Public Docket as referenced
1. Actual meteorological conditions recorded on the CVR from the pilots and professional ground crew indicate that the correct temperature and wind is 20 deg. C and 3-5 knots of headwind. At this condition the aircraft had 420-750 lbs. of weight margin as calculated from FAA approved performance charts (NTSB Hover Study, Coultas Response 455943).
2. Repeated independent flight tests commissioned by Carson at the same density conditions and weights exceeding the accident aircraft show that it had sufficient power to fly away, except when power was partially removed from one engine (Carson Submission, II-F, Exhibit 5, Docket 438758, 446197). The NTSB has repeatedly refused to consider this real data in favor of Sikorsky flight simulations using datasets from differently configured aircraft.
3. The #2 engine had rpm fluctuations the last flight day before the accident. The #2 engine had significantly less internal damage and wear patterns than #1, possibly indicating it was running at lower power. Recovered intact torque gauges indicate the #2 engine was producing 30% less torque at impact. The #2 emergency throttle was halfway engaged. The copilot recounted that he had engaged the #2 emergency throttle after seeing a torque loss to #2 on the gauges right before impact (455939 Douglass affidavit, Carson Submission, III-A through E, NTSB Operations Report, Docket 444680-444684)
4. Significant contaminants ranging in size up to 28 microns were recovered from inside the #2 Fuel control Pressure Regulating Valve. Particles bigger than 4 microns can jam the Fuel control unit and cause uneven fuel flow and power. There is significant history about contaminant problems in this Fuel control unit that has been discovered in this investigation (Carson Submission, IV-A through E, Exhibits 8, 10-23)