SEATTLE - A team of investigators with the National Transportation Safety Board has begun deconstructing pieces of a helicopter that crashed Tuesday morning shortly after taking off from the KOMO-TV helipad.
KOMO photographer Bill Strothman and pilot Gary Pfitzner were killed, when the helicopter crashed on top of cars near the Space Needle and burst into flames.
A 38-year-old man in one of those cars is now in serious condition at Harborview Medical Center.
Dennis Hogenson, the deputy regional chief of the Western Pacific Region of NTSB, said their team worked most of Wednesday to go over maintenance records, pilot records and operator records. Wednesday afternoon the team moved to a hangar in Auburn to go through what’s left of the AS-350 helicopter, owned by Helicopter Inc., and leased to KOMO and KING television stations.
“They have forecasted that it will probably take about three days and they plan on separating the engine from the wreckage later this afternoon, and examining specifically the engine and its subcomponents,” Hogenson said.
The NTSB team included representatives of Helicopter Inc. and the manufacturer of the helicopter's engine. After the team is finished reviewing the evidence, the engine will be sent back to the manufacturer in Texas. A preliminary report is due in about four business days. A final report may take about a year.
Hogenson said staff is still speaking to witnesses; the team has also yet to review surveillance footage.
“Seattle PD is going through the records for us, the video. Tomorrow morning we plan on meeting with them and reviewing the footage. A lot of the footage we’re seeing does not actually capture the events leading up to the accident,” Hogenson said.
The witness statements therefore become crucial. Many witnesses told KIRO 7 they heard strange noises, then saw the helicopter turning counterclockwise before falling to the ground.
While Hogenson would not speculate on the various reasons for the fall, experts who heard the descriptions said one possibility is a tail rotor malfunction. Mike Theilen, president of Glacier Aviation, said a tail rotor creates thrust to counteract the torque of the main rotor system.
“You can have a stuck pedal problem, where you can only input so much and create so much thrust,” Theilen said. “You can have a tail rotor drive shaft failure, or complete separation back here. And once that happens, you have zero thrust of the tail rotor.”
Without that tail rotor, the helicopter can turn violently counterclockwise. This type of situation can be remedied mid-air, according to Theilen. But that’s more easily done when the aircraft is flying at a greater speed, not when it’s hovering low to the ground.
“It’s just when the aircraft is at the wrong time and the wrong place when the tail rotor has a problem, that’s usually when it becomes a bigger mess,” Theilen said.
Roger Fox, who flew a KOMO helicopter for more than 20 years, helped design the current helipad from which the AS-350 took off Tuesday morning. Fox said he cannot imagine the helicopter hitting anything as it left. He said more and more tall buildings have been built around the helipad, which creates a bigger challenge.
“It really affected the airflow pattern coming across the roof, trying to take off,” Fox said. “Then as they kept building, your options for which direction you’re going to go were more and more limited. The biggest problem on day one, of course, is that you’re taking off over an urban environment.”
Hogenson said an operator of a construction crane was in communication with the pilot when the helicopter landed from its earlier flight. Such communication is normal in that area and there was nothing out of the ordinary about that landing. There were also no issues reported when the helicopter covered a water main break earlier in the morning. NTSB officials also did not find any obvious signs of anything being hit on the helipad.
Fox said the loss of Pfiztzner and Strothman is hard and he feels for both families.
Fox said he knew the risks of the business when he started flying.
“It’s one of those personal moments you’ve got to discuss with yourself. How serious are you about this business?” he said.