ISLAND COUNTY, Wash. — The National Transportation Safety Board (NTSB) deployed a team of seven investigators to assess a deadly plane crash that took place near Whidbey Island over the weekend.
The United States Coast Guard confirmed the identities of all 10 victims on board. The plane was flying from Friday Harbor to Renton Municipal Airport in a scheduled commercial commuter flight when it crashed on Sept. 4. One victim has been recovered so far.
The plane that crashed was a de Havilland DHC-3 Otter, a single-engine propeller plane, according to the NTSB. The plane was operated by West Isle Air doing business as Friday Harbor Seaplanes, which is a service owned by Northwest Seaplanes.
A spokesperson for the NTSB said an investigation into the crash could take anywhere from 18 to 24 months. The actual duration is uncertain depending on how attempts to recover the aircraft go.
"Our mission is to understand not just what happened, but why it happened, and to recommend changes to prevent it from happening again," said Tom Chapman with the NTSB.
Chapman said he was "confident" the NTSB would be able to locate the plane wreckage. The NTSB is coordinating with the National Oceanic and Atmospheric Administration for search efforts. The search requires "advanced equipment capable of searching larger underwater areas," an NTSB spokesperson said.
How the aircraft will be recovered will depend on what depth the aircraft is located at and what condition it's located in. Investigators have yet to find out if the aircraft broke up in the water or how widely the debris might be spread.
Chapman estimated the aircraft is currently at a depth of 100 to 300 feet.
Some items from the airplane have been recovered, according to the NTSB, including foam fragments from the plane's floats, a seat cushion, a seatbelt, dispatch paperwork, flooring structure remnants and some personal items from the victims.
NTSB Disaster Assistance staff is working with family members to return the personal items that were recovered, a spokesperson said.
The aircraft may have been at about 1,000 feet in the air at its highest altitude, according to flight data. There is some indication that the plane took a nose dive. Chapman said that data would be analyzed "thoroughly" so they know what the exact performance profile of the aircraft was.
The NTSB will look at operations, airplane structures and airplane systems in its investigation into what went wrong. The on-scene investigation team is collecting maintenance records, pilot records and training records from the operator of the plane.
The investigative team has already collected the FAA's ADSB aircraft surveillance data, which recorded the airplane's position and altitude. NTSB investigators and staff at the organization's headquarters in Washington D.C are also collecting weather and air traffic control information, as well as analyzing the ADSB data.
Chapman said there was no indication of a distress signal or beacon from the aircraft, however, experts said it would be difficult to detect a beacon underwater.
The FAA, West Isle Air, GE Walter Engines and the Transportation Safety Board of Canada (TSB Canada) will provide additional information over the course of the investigation, Chapman said. Viking Air is the type certificate holder on the aircraft design and will be a technical advisor to TSB Canada.
The NTSB encourages witnesses or those with information relevant to the investigation such as videos or photographs to email the NTSB at witness@NTSB.gov or call at 866-328-6347.