An airplane that crashed into the mountainside near White Pass on Sunday, killing 10 men and women with Skydive Snohomish, went through some harrowing maneuvers in its last seconds.

The Cessna 208B Grand Caravan made a tight 360-degree turn, and then lost 1,400 feet of altitude over the next 12 seconds, according to radar data, the National Transportation Safety Board said Friday.

There appeared to be a moment of respite before the plane fell from the sky.

“The aircraft appeared to recover and stayed at 13,000 feet for three radar hits before it entered a rapid descent of 6,800 feet per minute to the last radar hit at 8,900 feet,” the NTSB said.

The agency used radar “ping” data collected every six seconds to track the flight until just before it crashed at about 5,000 feet in the Cascade range near White Pass. Earlier, investigators estimated the plane was going about 70 mph when it nosed into the ground.

The plane, carrying members of the Harvey Field-based skydiving club, left Star, Idaho, near Boise, on its way to Shelton, in Mason County. It was ferrying sky divers between Idaho and Washington after a weekend of jumping with other sky diving groups.

A preliminary report on the accident likely will be released next week, said Keith Holloway, spokesman for NTSB. A cause likely will not be determined for more than a year.

During that time investigators will try to determine if adverse weather, which appears to have been present at the time of the crash, was a contributing factor.

Possibilities include ice building up on the wings, pilot disorientation after flying into a cloud, or a downdraft that could have forced the plane down.

The Cessna 208 has come under scrutiny by NTSB because of the number of crashes that have occurred when ice has built up on its wings. The small plane does not carry a flight data recorder. No flight plan was filed.

Mechanical problems and pilot error also will be investigated as possibilities, officials said.

“It’s too soon to determine a cause at this time,” Holloway said. “We don’t speculate.”

Holloway said the hope is to fly many of the plane crash pieces off the mountain today. He said they would be moved so they can be studied to see what might have caused the crash.

Reporter Lukas Velush: 425-339-3449 or lvelush@heraldnet.com