NTSB Updates Investigation Into Seaplane Crash

National Transportation Safety Board (NTSB) investigators identified a possible safety issue with a flight control of the De Havilland Canada DHC-3 that crashed into Mutiny Bay, Washington on Sept. 4, 2022 that killed all 10 people abaord.

Investigators found the horizontal stabilizer actuator separated into two pieces. During an exam of the threads inside the barrel and the threads on the clamp nut, those pieces separated by unthreading instead of being pulled apart as a result of tension. A wire lock ring, not yet found in the wreckage, is used to prevent the barrel and clamp nut from unthreading.  This could have resulted in a possible loss of airplane control.

The wreckage recovery was completed on September 30 with roughly 85% of the airplane recovered from the sea floor. A field examination of the wreckage occurred the week of October 3, with follow-up at the NTSB Materials Laboratory in Washington, D.C.  The investigation into the accident continues.