Experts look into possible cause of float plane crash that killed 10 off Whidbey Island

The National Transportation Safety Board is investigating the deadly crash of a float plane off Whidbey Island on Sunday, and experts ranging from former pilots to aviation attorneys are weighing in on what could have potentially caused the tragedy.

The single-engine float plane that crashed was a DHC-3 Turbine Otter, according to the NTSB. The plane is about 200 feet deep in the water, according to South Whidbey Fire/EMS.

While the Coast Guard handed over its findings to the NTSB to investigate the crash, if more debris washes ashore as they expect it will, Coast Guard search crews would likely return.

Meanwhile, experts are sharing what might have gone wrong with the floatplane as it made its way to Renton.

Kathleen Bangs is a former commercial and floatplane pilot. She said she looked at the FlightAware flight tracker data and the plane plummeted 700 feet into the water.

“Was there some kind of structural failure that happened so suddenly that there was absolutely nothing the pilot could do? Because it appears this airplane hit the ocean totally out of control,” said Bangs.

Bangs said among the things investigators will look at is whether the pilot was incapacitated, if the plane struck a bird or drone and how well the plane was maintained.

The area where the floatplane went down was mostly quiet on Tuesday, with only a Washington State Department of Fish and Wildlife dive boat in the area.

“This is wreckage that needs to be located immediately and pulled up immediately. I don’t understand why the Navy is not out there,” said Seattle aviation attorney Alisa Brodkowitz, who litigated previous seaplane crashes.

She said the plane needs to be found with sonar.

“Every minute that ticks by when the Navy is not out there with its sonar and its experienced divers means evidence lost, and that means these families won’t get closure without that wreckage,” Brodkowitz said.

John Paul Johnston, executive director of the Divers Institute of Technology, said the plane is likely in pieces and drifting deep in currents and countercurrents.

Johnston says the plane can be found with sidescan sonar, and said bringing in a salvage company is another way to find the plane.

“They’ll be a lot of vessels out here, companies, that carry that type of equipment,” Johnston said.

Brodkowitz is focused on the structural integrity of the de Havilland DHC-3 Otter.

She said the 1963 plane’s history shows a conversion from a piston to a turbine engine,, which is commonly done to give the plane more speed and faster lift.

To compensate for a change in the center of gravity, the plane’s nose was extended.

“The structure of the airplane changes in the front, a firewall forward, not a lot of structural changes in the rest of it; and then you put this superfast engine in it and then there are problems,” Brodkowitz said.

Brodkowitz said engine conversions have led to structural fatigue and crashes in the past.

She wants the FAA to immediately require the operators of Otters with conversions to do robust structural inspections.

Navy officials told KIRO 7 they are not aware of any requests to use their assets to find the plane.

KIRO 7 asked the owner of Northwest Seaplanes if he plans to hire a salvage company, or if the company is now doing extra inspections, but he didn’t reply.

However, officials with the NTSB arrived in Washington state and gave an update Tuesday evening on the crash.

According to investigators, the plane was traveling at about 1,000 feet when it plunged into the water.

Despite storm conditions at the time, KIRO 7 found out the plane seemed to be flying at a steady altitude for the flight and in the air much longer than first thought.

Investigators said the plane was flying for 35 minutes when it crashed, which is nearly double the time that KIRO 7 crews were first told.

Pilot records and the plane’s maintenance records have been obtained, investigators said.

They are also looking through air traffic control data and weather information.