The Robinson Helicopter Company was established in the US in 1973 and produced their first R22 helicopter in 1979. Since that time they have manufactured tens of thousands of helicopters of models R22, R44 and R66. The R22 is a two seat light helicopter, the R44 is a larger four seater. Both the R22 and R44 models are piston powered, the Lycoming O-320 engine being used in the earlier R22 models and the O-360 in the later series, and O-540 engine models powering the R44. The R66 uses the Rolls Royce RR300 gas turbine, a derivative of the long-lived Allison 250, but is otherwise similar to the R44 on which it is based, the turbine having a power rating nearly identical to the piston engine of the earlier model and the main benefits of turbine power being lower engine weight and therefore greater load capacity plus smoother flying, against the much higher operational / maintenance costs of a turbine engine. Robinson helicopters are very popular worldwide because of their very low purchase price. However, there is some question over whether this also translates into lower maintenance costs; for example the Guimbral Cabri G2 light helicopter which fits somewhere between the R22 and R44 in specs, claims to have lower maintenance costs due to greater life limits on major components, but is more expensive to purchase.
Against the lower purchase and possibly operational and maintenance costs has to be considered the simpler and lighter nature of these helicopters compared with those made by other manufacturers such as Hughes / Schweizer, Bell and Enstrom, etc. The rotor system is notably lightweight in nature and the rotorhead system is a teetering design which is somewhat susceptible to mast bumping, a situation in which the rotor head can snap off the mast (shaft) due to excessive tilting of the rotor blades relative to the helicopter body. Whilst this type of issue is not limited to Robinson helicopters, the combination of this design in conjunction with the lightweight rotors and other factors originally lead to a relatively high accident rate of R22 model rotorcraft. This resulted in the imposition of special requirements for pilot training and instructor certification in SFAR 73 by the Federal Aviation Administration, which was later extended to the R44 series. This brought the rate of these accidents down dramatically in the US.
However in New Zealand, these lessons took a long time to be learned, and as at 2015, the rate of mast bumping related crashes of Robinson helicopters here was around 800% more than in the US. The reason for the problem? Well there are many possible causes, but pilot error has to take a leading place because our Civil Aviation Administration did not mandate the same type of restrictions as were imposed in the USA on the training and certification of pilots. Not only was there a lack of proper effort to train pilots, the CAA did not implement the US requirement for certification and registration of instructors. The result was that before 2016, not many NZ instructors for Robinson helicopters knew about all of the special issues in flying these machines, and from this it can be reasonably inferred that many pilot trainees did not receive adequate instruction in these factors either. This poor decision making by bureaucrats is probably almost certainly responsible for the numerous accidents and deaths in Robinson helicopters in the past two decades in NZ.
Calls for these helicopters to be banned in NZ are unlikely to succeed, the real problem is the concerted failure of CAA to implement TAIC’s safety recommendations for these machines for decades, but we are certain no bureaucrat is about to accept responsibility for the situation. After the deaths at Cave Creek it was impossible to get any accountability from the Department of Conservation, the same applied to the Pike River mining disaster and the collapse of the CTV Building in Christchurch’s 2011 earthquake.