Robinson R22 helicopter pilots are being reminded to know the limits of their aircraft following the release of the ATSB investigation report into the reliability of the R22 belt drive system.
The ATSB conducted the investigation in response to several R22 accidents and serious incidents caused by the failure of one or both rotor drive v-belts. Between 2004 and 2012, there were eight occurrences reported to the ATSB. The v-belts are crucial components which transmit engine power to the helicopter's main and tail rotor blades.
Pilots, operators and maintainers should pay particular attention to the installation and condition of R22 drive belts and other components of the drive system.
The report identifies a number of key factors that affect the reliability of the R22 drive belt system. These include:
- flying the aircraft with too much weight on board
- pushing the aircraft’s engine beyond its limits
- failing to maintain the drive system or ensuring the drive sheaves are aligned
- failing to conduct adequate or frequent inspections of the rotor drive system.
During the investigation, the ATSB issued a safety advisory notice, cautioning Robinson R22 pilots of a drive belt risk and urging them to check their R22 helicopter drive system regularly for misalignment, abnormal wear or other indications of drive belt damage.
The Robinson R22 helicopter is the most popular light utility helicopter used in Australia and has a reputation for being an extremely reliable machine. As of June 2012, there were over 500 Robinson R22 helicopters on the Australian Civil Aircraft Register.
Owners and operators should fully appreciate the nature and effects of the operational stresses placed on the helicopter, particularly if the machine is used in a dynamic and demanding way.
Read the full investigation report, AI-2009-038 – Reliability of the Robinson R22 helicopter belt drive system.