NTSB preliminary report details Kenmore Air Otter floatplane crash in Washington state

The National Transportation Safety Board has released a preliminary report on last month's crash of a de Havilland DHC-3 Otter floatplane operated by Kenmore Air in Washington state.

The accident happened on July 23 at around 5:20 p.m. local time near Eastsound, according to the report. The aircraft, registered N709KA, was operating as a scheduled Part 135 air taxi flight that had departed Kenmore Sea Base in Seattle with planned stops at Roche Harbor and Friday Harbor.

The pilot and two passengers were seriously injured. Eight other passengers suffered minor injuries, and the airplane sustained substantial damage.

ADS-B data cited by investigators shows the aircraft flying low over water, between roughly 500 and 1,000 feet, as it headed north over Rosario Strait before turning toward Sucia Island. According to the operator, the pilot radioed to say deteriorating weather had made it impossible to continue to Roche Harbor, and that he intended to land near Sucia Island to wait it out. Multiple bays around the island were authorized landing areas, the operator said.

Witness video reviewed by investigators reportedly shows the floatplane just a few feet above the water in a nose-high attitude as it descended toward Shallow Bay. The left wing dropped when the aircraft was about four feet above the surface, according to the NTSB's account. The left wingtip and pontoon float struck the water, and the plane then came down on both floats and continued forward.

The report is preliminary. A final determination of cause has not yet been issued.