PETALUMA, Calif. (KTVU) -Sonoma County Coroner's officials were working to notify next of kin before releasing the name of a pilot who died in a rural crash.
The tail number on the ultralight aircraft shows it registered to a Petaluma man.
"We're on scene collecting that portion of the investigation itself," NTSB accident investigator Joshua Cawthra told KTVU at the crash site southeast of the airport.
Cawthra arrived shortly after the 12:30 p.m. crash, assisted by the FAA and Sonoma County Sheriff's Deputies, picking through the crumpled plane.
The model was a two-seater, but the pilot was the only occupant.
It was fixed-wing, with a single engine, but very lightweight and classified as "experimental" because an enthusiast can order a kit, and build it themselves.
Word of the fatal crash circulated around the airfield.
"It's a very sad day," pilot David Shoemaker told KTVU, stepping out of his Beechcraft Bonanza, "but I think there's risk in everything we do and we all kind of accept that."
Ultralights are popular at Petaluma's small airport.
"It's as close to being a bird as you can possible get," observed Dan Kelly, owner of the Two Niner Diner, the airport cafe.
YouTube videos of flight in a Quicksilver MXL Two, like the one that crashed, show it to be very open-air, without much structure but clear visibility for sightseeing. It flies low and slow, compared to heavier planes, and is very responsive to the pilot.
"What you do is shift your weight, it's like a hang glider," explained Kelly, "so the plane moves with you."
FAA records show the current owner bought the 30 year old plane one year ago.
Why it ended up in pieces, sandwiched between pastures and vineyards, is a mystery.
Some witnesses said one of the wings appeared folded as the aircraft nosedived.
A dozen vineyard workers watched from only a few hundred feet away.
"Everybody saw when the plane went down," vineyard supervisor Hugo Gallando told KTVU," and some people ran to it and tried to help but there was nothing we could do."
The NTSB says it will be weeks, maybe months, before it comes up with the cause, but admits the aircraft design provides little protection.
"There's no enclosure," acknowledged Cawthra, "it had a windscreen. But you're somewhat out in the open air."
Cawthra added that he'll be reaching out to at least a half dozen solid witnesses who saw the plane spiral down.