SNOHOMISH — The National Transportation Safety Board has recovered wreckage of the small plane that crashed during a test flight near Snohomish on Friday, killing all four on board.

An agency spokesperson said Monday the Cessna 208B’s right wing fell off on a morning flight from Renton. The plane had been maneuvering near Harvey Field Airport when it suddenly crashed into a field near U.S. 2 and 100th Street SE. Investigators found the wing about 200 yards away from the plane’s fuselage.

The wreckage will be taken to a secure facility for reconstruction, according to the NTSB.

A preliminary report on the crash is expected in two to three weeks. The final report, which would identify the probable cause for the crash, could take one to two years.

On Monday, investigators were collecting maintenance records for the plane and information about the pilots, including their licences, ratings and histories.

The crew, including “two highly-experienced test pilots,” was collecting baseline aircraft performance data at the time of the crash, according to Raisbeck Engineering, the Seattle company leasing the plane.

“This is a standard industry practice that allows aviation engineering firms to establish baseline aircraft performance under a highly structured flight profile to later measure and compare the change in performance after any proposed modifications are installed,” the company’s president Hal Chrisman said in a statement. “The aircraft was in this initial testing phase and had not yet been modified in any way by Raisbeck.”

The Grand Caravan plane could’ve seated up to 14 people.

The pilots both had over 10,000 flight hours, Chrisman noted. The crew also included a flight test director and an instrumentation engineer.

The four victims had not been identified as of Monday afternoon. The Snohomish County Medical Examiner’s Office said it would identify them by the late afternoon, at the earliest.

Anyone with information that could be relevant to the investigation, including witnesses, were encouraged to contact the NTSB by email at witness@ntsb.gov.

Jake Goldstein-Street: 425-339-3439; jake.goldstein-street@heraldnet.com; Twitter: @GoldsteinStreet.