FRESNO, Calif. (AP) — Federal investigators scoured the site of a fatal helicopter crash in the Sierra Nevada mountains Wednesday, trying to determine whether it might have been caused by a lack of markings on a high-voltage power line spanning the river canyon.
Three state scientists and the pilot were killed Tuesday when the Bell 206 helicopter clipped a Southern California Edison transmission line, sparking a blaze that consumed the craft and sent debris flying.
The team had been conducting a deer survey in a craggy stretch of the mountain range where electric lines crisscross the canyons, sucking up hydropower generated by dams.
Federal Aviation Administration guidelines state that companies are responsible for placing lights and visible markers on power lines and towers that are higher than 200 feet above ground level, so that pilots can spot potential hazards, said spokesman Ian McGregor.
SoCal Edison spokesman Steve Conroy confirmed Wednesday that the transmission line, in place for decades, was not marked. The FAA did not ask the company to mark it, he said.
Killed in the crash were longtime scientists Clu Cotter, 48, and Kevin O’Connor, 40, and a scientists’ aide, Tom Stolberg, 31, all of Fresno. Experienced pilot Dennis Michael Donovan, 70, of Palm Springs, also died.
Gov. Arnold Schwarzenegger ordered flags at the state capitol flown at half-staff Wednesday, while the biologists’ former colleagues began collecting donations to a memorial fund.
National Transportation Safety Board investigators will spend the next two weeks examining the helicopter’s blackened hull, radar and air traffic control data, as well as interviewing eye witnesses before issuing a preliminary finding about the probable cause.
If investigators find that the utility company — a subsidiary of Edison International — shirked its duty to mark the power line, it could be held partially legally responsible for the crash, experts said.
“Depending on what angle you’re flying at and where the sun is, these wires can be invisible to pilots. That’s why it’s so important to have these things marked,” said Stuart Fraenkel, a Los Angeles attorney who specializes in aviation litigation. “If a court or a jury finds they had a duty to mark this particular wire, then absolutely they could be found to have contributed to this accident.”
The state Department of Fish and Game does aerial deer surveys each winter, but those involved acknowledge the voyages can be risky since they often involve flying close to the ground.
Donovan worked for a contractor, Landells Aviation of Desert Hot Springs, which the FAA has cited three times for minor violations of federal aviation rules, McGregor said.
Another Landells helicopter crashed in January 2007 during a deer-monitoring trip in the nearby Tulare County foothills, and the three men aboard suffered minor injuries when the chopper hit trees and terrain.
The NTSB later found that the probable cause of that crash was “the pilot’s failure to maintain terrain/obstacle clearance while maneuvering.”
Fish and Game temporarily has grounded all wildlife monitoring helicopters until investigators find out what caused the crash and adjustments can be “made if necessary,” spokeswoman Jordan Traverso said.
Even so, she said the department plans to continue the aerial deer surveys because they are cheaper than ground-based missions and provide scientists with better population data.