Following an investigative report on the causes of a New Zealand helicopter crash, Robinson Helicopter Co. has been added to the country’s “most pressing concerns” watchlist. New Zealand’s Transport Accident Investigation Commission added the helicopter company to its watchlist on October 27, 2016, following multiple fatal Robinson helicopter crashes in the past two decades. Additionally, the commission expressed concern that four of its recommendations to reduce the number of incidents had not been implemented, leading to worries about the possibility of future helicopter accidents.
Mast Bumping in Robinson Helicopter Crashes
The Transport Accident Investigation Commission (TAIC) noted that in the past 20 years, 14 “mast bumping” accidents involving Robinson helicopters resulted in 18 deaths. Six of those accidents were in the past four years. A mast bump occurs when the inner section of a main rotor blade or rotor hub makes contact with the main rotor drive shaft (also known as the mast). According to the commission, the result of a mast bump is usually catastrophic.
Due to the risk of mast bumping, the commission said it is concerned about the danger of flying Robinson helicopters in certain terrain and weather conditions. Specifically, it cited New Zealand’s mountainous terrain, the strong winds, and the exposure to turbulence as factors increasing the risk of a mast bump.
A spokesperson for the commission said that although investigators know what mast bumping is, they are not sure what causes a mast bump to occur.
“We know the condition results when a low-G occurs-a bit like when you leave your stomach behind when going over a hump on a country road-or from an inappropriate control input,” said Commissioner Stephen Davies Howard. “Low-G can be caused by turbulence, but it is not normally a condition that causes concern beyond discomfort.”
Mast bumping, the TAIC notes, often result in the helicopter breaking up while in cruise flight. It is almost always fatal for the people on board, which makes it difficult to determine what caused the mast bump to occur. Robinson helicopters have semi-rigid two-bladed main rotor systems, which may be more susceptible to mast bumping than are other brands of helicopters, especially if they are being flown with high power settings, at high speed, and with low weight, according to the commission.
With around 300 Robinson helicopters registered in New Zealand, Robinson helicopters reportedly make up around 40 percent of the total number of helicopters in the country. Officials note that although the U.S. Federal Aviation Administration (FAA) has implemented strategies to prevent in-flight break-up accidents, the rate of such New Zealand helicopter crashes has not been reduced.
Is Pilot Training a Concern in NZ Helicopter Accidents?
The TAIC recommended that pilots should be aware of the factors associated with mast bumping, including low-G conditions. Though the commission also warned that the manufacturer should clearly state what the helicopter’s operating limitations are.
In its report on a 2015 New Zealand helicopter crash, the TAIC found the Robinson R44 broke up while in flight after one of its rotor blades collided with the cabin. However, the commission said it could not conclusively determine what caused mast bumping in that situation. The commission did state that it found no evidence of a mechanical defect that contributed to the accident, but concluded the report stating pilots should avoid low-G conditions, rather than assuming they can encounter low-G and recover from it.
The report stated that there have been many other fatal mast bump accidents involving Robinson helicopters in New Zealand and around the world that have gone largely unexplained,” the report noted. The report also stated that It is difficult to identify the lessons from an accident and make meaningful recommendations to prevent similar accidents if the underlying causes cannot be determined.
A pilot instructor and student were both killed in the accident. The families of the victims have argued Robinson helicopters should be banned from New Zealand.
Robinson Helicopters has said the issue is with preventable pilot error. Ron Goldman, attorney at Baum Hedlund Aristei & Goldman, argues the cause is likely a problem with the helicopter design and not an issue of pilot training.
“That needs to be rooted out and redesigned or the ship shouldn’t fly,” Goldman said. “It’s very surprising to see this kind of repetitiveness. We’ve handled cases against almost every single manufacturer; you see nothing like the quantity you see with Robinson.”
New Zealand Helicopter Crash Avoidance Recommendations Not Implemented
New Zealand’s commission also expressed concern that Robinson flight manuals do not highlight critical safety information that could result in helicopter crashes and injury or death. Further, it noted that four of its recommendations in regards to mast bump accidents had not been implemented, raising concerns that a similar helicopter crash could occur in the future, with tragic results.
Helicopter Crash Attorney
Attorneys at Baum Hedlund Aristei & Goldman have extensive experience representing victims of helicopter crashes. If you or a loved one has been injured in a helicopter crash, contact us online or call (855) 948-5098 to discuss your legal options.