Mast cracking involving Robinson R44, VH-RTB, at Tindal Airport, Northern Territory, on 28 April 2026

Summary

The ATSB is investigating mast cracking involving a Robinson R44, registered VH-RTB, in the Northern Territory, on 13 March 2026.

The operator noted balance issues with the helicopter and arranged for corrective maintenance. During balance adjustments, the maintainer observed a crack around the mast’s circumference, just above the main rotor gearbox. The gearbox was disassembled and examined at a secure facility, and the mast was removed for a more detailed examination at the ATSB's engineering facility in Canberra.

The investigation was deferred on 5 June 2026 while awaiting delivery of components, and external resources to conduct the gearbox disassembly. The investigation resumed on 22 July 2026.

The ATSB has completed the evidence collection and analysis phases of the investigation and is drafting the final report.

The final report will be released at the conclusion of the investigation. Should a critical safety issue be identified during the course of the investigation, the ATSB will immediately notify relevant parties, so that appropriate safety action can be taken.