The United States National Transportation Safety Board (NTSB) is investigating an accident involving an amateur-built Beck Michael J Sonex, registered N920MB, near Auburn Municipal Airport, Washington, United States, at about 1130 local time on 16 January 2024.
The pilot reported that while climbing after take-off, a partial engine power loss occurred, and the aircraft began descending. The pilot then planned to conduct a forced landing on a road straight ahead of the aircraft but several seconds later, the engine regained power enabling a climb. About 40 seconds later, the engine lost all power and the pilot turned the aircraft toward the airport. The aircraft then collided with signage structures and terrain and was substantially damaged. The pilot was not injured.
As part of the investigation, the NTSB identified an Australian-manufactured Rotec Aerosport TBI Mk 1 throttle body in the aircraft wreckage and considered it an item of interest. To support the investigation, the NTSB requested assistance and the appointment of an accredited representative from the ATSB to facilitate manufacturer examination and functional testing of the throttle body.
To facilitate this support and to provide the appropriate protections for any relevant information, the ATSB appointed an accredited representative in accordance with paragraph 5.23 of the International Civil Aviation Organization Annex 13 and commenced an investigation under the Australian Transport Safety Investigation Act 2003.
To ensure the integrity of the material evidence and to provide independent oversight, ATSB personnel were required to be present for the Australian manufacturer’s examination and testing of the throttle body. However, Rotec Aerosport would not permit ATSB personnel to be present and therefore, the NTSB elected not to proceed with the testing.
As no further involvement has been requested, the ATSB has closed this investigation.