Following numerous accidents involving Robinson Helicopters-including helicopter crashes both at home and internationally-the U.S. Federal Aviation Administration (FAA) has issued a proposed airworthiness directive regarding Robinson Helicopter Company Model R66 aircraft. The FAA issued the airworthiness directive on March 30, 2018, and has given respondents until May 29, 2018, to submit comments.
In New Zealand, the Department of Conservation permanently grounded its fleet of Robinson aircraft due to concerns about mast bumping. Critics have argued that Robinson helicopters are too prone to in-flight break-up, putting those on board at risk of catastrophic injuries or death.
FAA Proposes Inspecting Robinson Helicopter’s Tail Rotor Drive
The FAA issued the proposed airworthiness directive in response to reported unsafe conditions in Robinson R66 aircraft.
“This proposed AD would require replacing the tail rotor drive shaft yoke assembly and inspecting for sealant,” the FAA writes. “This proposed AD is prompted by reports of tail rotor driveshaft failures. The actions of this proposed AD are intended to correct an unsafe condition on these products.”
Included in the proposed airworthiness directive are all Robinson Model R66 helicopters with serial numbers 0003 through 0752, with a tail rotor drive shaft assembly part number D224-3 or D224-4 installed. All aircraft included in the directive would have to undergo an inspection for sealant in the tail’s forward yoke assembly within 100 hours time-in-service and have the tail rotor drive shaft’s forward yoke assembly replaced. If a sealant is needed, then it would be applied at that time.
Proposed Airworthiness Directive Follows Two Incidents of Bearing Failures in R66 Helicopters
The FAA issued its proposed airworthiness directive after two incidents in which a bearing that was too small for its housing caused excessive heating, break down of the bearing grease, and seizure of the bearing. According to the FAA, Robinson was aware of this manufacturing or design issue with its helicopters and recommended a temperature recorder be installed on the tail rotor driveshaft bearing assembly to monitor the temperature. If the temperature became too hot, Robinson recommended the bearing be upgraded.
The results of bearing failure could be deadly.
“The actions specified by this AD are intended [to] prevent failure of the tail rotor driveshaft forward bearing and subsequent loss of helicopter control,” the FAA writes. The agency goes on, “We are proposing this AD because we evaluated all known relevant information and determined that an unsafe condition exists and is likely to exist or develop on other products of these same type designs.”
The FAA notes that 249 helicopters would be affected by the proposed airworthiness directive, at a cost of $1,423 per helicopter.
New Zealand Agency Permanently Grounds Robinson Helicopters
While the FAA issued proposed airworthiness directives, a government agency in New Zealand has permanently stopped all use of Robinson helicopters, due to the excessive rate of fatal accidents. In 2016, the country’s Transportation Accident Investigation Commission added Robinson helicopters to its “Most Pressing Concerns Watchlist.” The same year, New Zealand’s Department of Conservation announced a temporary suspension of Robinson aircraft, due to issues with mast bumping. In that time, the department conducted a review and determined the safe move was to stop using Robinson helicopters entirely.
“Having assessed the evidence, we’ve made a decision to err on the side of caution and permanently cease the use of Robinson helicopters to transport DOC employees,” said Department of Conservation Safety Director Harry Maher. “Ensuring employee safety in Robinson helicopters relies heavily on pilots flying within strict operating limits at all times. We aren’t confident that we can rely on this consistently over time across the many varied conditions that DOC employees face when in helicopters.”
According to reports, almost 50 percent of helicopter crashes in New Zealand involve Robinson aircraft, even though they make up about 35 percent of the country’s entire fleet. Robinson aircraft are also responsible for 64 percent of all fatal crashes in the country.
Robinson Issued Guidelines About Passenger Risks
Robinson may have attempted to alleviate concerns about mast bumping accidents in a safety notice, but an aviation expert told New Zealand’s Department of Conservation the notice was bizarre. The Herald reports that Robinson warned that carrying passengers in the helicopters increases the workload and distraction, which can increase the risk of a crash.
John Fogden, director of Total Aviation Quality, assessed the notice for the Department of Conservation and said he had never seen a similar warning by any helicopter or fixed-wing manufacturer. Fogden suggested that Robinson was blaming mast bump accidents on having passengers in the helicopter, rather than on a design flaw. Robinson has also blamed accidents on a lack of pilot training. In his assessment for the Department of Conservation, Fogden noted that while most manufacturers use safety notices to warn about issues with their aircraft, Robinson appears to use safety notices to blame pilots for accidents.
In the U.S., Robinson has already been involved in a fatal crash this year. In January, three people died when a Robinson R44 crashed into a house in Newport Beach, California. In 2017, two men went missing in Hawaii after the Robinson R44 they were in disappeared. In February 2018, three people also died in Canada when the Robinson R44 carrying them crashed into a field.