FAA mandates replacement of R22 & R44 main rotorblades
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Rich B,
The short answer is yes. My 44 RII, with -7 blades (fitted as per the requirement around 5 years ago) have started to delaminate. To the extent they are U/S. I have to buy new ones. I am understandably not happy. It's flown on the east coast of Australia, Robbie are blaming the salt air.
I hope that helps.
Arrrj
The short answer is yes. My 44 RII, with -7 blades (fitted as per the requirement around 5 years ago) have started to delaminate. To the extent they are U/S. I have to buy new ones. I am understandably not happy. It's flown on the east coast of Australia, Robbie are blaming the salt air.
I hope that helps.
Arrrj
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And we've been flying around with our -5 blades for a total of 2197 FH in a salty environment and are heading for the overhaul now to replace them with -7 blades. No delamination at all.
Finding out which is very difficult, especially with a flight critical component.
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Blade production processes
Perhaps there is some peculiarity in the manufacturing process which produces these variations in the blade sensitivity. Materials are often poorly understood, so sometimes a processing step turns out to be detrimental rather than beneficial.
Finding out which is very difficult, especially with a flight critical component.
Finding out which is very difficult, especially with a flight critical component.
Before the suspicions start, NO, I am not a lawyer, journalist or other parasite and I am not a total Robbie basher. Google "A08_25_29 Recommendation" and realise that my input directly led to that report. My issue is that while it is regulated that for certification it is required that an OEM must demonstrate static strength, fatigue resistance and damage tolerance, but there is no current regulatory requirement to demonstrate that an adhesive bond must maintain structural integrity over the entire component (non-fatigue related) life. That is what the report finds.
Regards
Blakmax
Blakmax
Here is the NTSB Safety Recommendation referenced by blakmax above:
https://www.ntsb.gov/safety/safety-r.../A08_25_29.pdf
https://www.ntsb.gov/safety/safety-r.../A08_25_29.pdf
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Before the suspicions start, NO, I am not a lawyer, journalist or other parasite and I am not a total Robbie basher. Google "A08_25_29 Recommendation" and realise that my input directly led to that report. My issue is that while it is regulated that for certification it is required that an OEM must demonstrate static strength, fatigue resistance and damage tolerance, but there is no current regulatory requirement to demonstrate that an adhesive bond must maintain structural integrity over the entire component (non-fatigue related) life. That is what the report finds.
Regards
Blakmax
Blakmax
He helped us with a Bell 212 main rotor blade debonding in 2006 that came very close to killing me.
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Hi Old Dog
You are too modest Old Dog. It was your excellent observation during pre-flight that saved your life. After that, it was pure chance that I knew the guy from DTA that was looking at the issue, and between us we worked out what was happening. A bit of cross-the-ditch cooperation helped.
Arjj, I'd really appreciate a PM with photos.
All the best
Blakmax
Arjj, I'd really appreciate a PM with photos.
All the best
Blakmax
Last edited by blakmax; 1st Aug 2019 at 10:05. Reason: Stupid corrective text editing overwriting reality.
Could the difference between Arrj's and Spunk's blades be due to temperature and humidity since Germany and E Coast Oz are very different environments?
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Environmental effects
Hi Crab,
Firstly, the blades I have worked with were not in AUS but they were in a tropical island location, so your point is transferrable. The issue of bond degradation is related directly fly to hydration of oxides on the surface off metals, and the surface preparation processes used during manufacture. Ideally the preparation process will produce hydration resistance, but older processes only provide short term resistance, and the susceptible surfaces eventually hydrate and the bond dissociates, leading to disbanding. This process is more rapid in hot-wet environments where the surface is susceptible to degradation, but in reality the main issue is the ability of the production processes to prevent hydration. The reason I am not bashing Robinson is that there is no specific regulatory requirement for a manufacturer to demonstrate resistance to hydration.
If I could get photos of the failure surface, I could provide an assessment of the causes of bond failures.
Regards
Blakmax
Firstly, the blades I have worked with were not in AUS but they were in a tropical island location, so your point is transferrable. The issue of bond degradation is related directly fly to hydration of oxides on the surface off metals, and the surface preparation processes used during manufacture. Ideally the preparation process will produce hydration resistance, but older processes only provide short term resistance, and the susceptible surfaces eventually hydrate and the bond dissociates, leading to disbanding. This process is more rapid in hot-wet environments where the surface is susceptible to degradation, but in reality the main issue is the ability of the production processes to prevent hydration. The reason I am not bashing Robinson is that there is no specific regulatory requirement for a manufacturer to demonstrate resistance to hydration.
If I could get photos of the failure surface, I could provide an assessment of the causes of bond failures.
Regards
Blakmax
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Firstly, the blades I have worked with were not in AUS but they were in a tropical island location, so your point is transferrable. The issue of bond degradation is related directly fly to hydration of oxides on the surface off metals, and the surface preparation processes used during manufacture. Ideally the preparation process will produce hydration resistance, but older processes only provide short term resistance, and the susceptible surfaces eventually hydrate and the bond dissociates, leading to disbanding. This process is more rapid in hot-wet environments where the surface is susceptible to degradation, but in reality the main issue is the ability of the production processes to prevent hydration. The reason I am not bashing Robinson is that there is no specific regulatory requirement for a manufacturer to demonstrate resistance to hydration.
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paint
Regrettably paint will not stop moisture absorption, it will only slow it for a while. The best thing about looking at the paint is that any disbond will cause fracking in the paint and that may* become obvious before the disbond becomes critical.
I thought that real;acement of -5 blades was already mandatory by now???
Blakmax
I thought that real;acement of -5 blades was already mandatory by now???
Blakmax
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I thought that real;acement of -5 blades was already mandatory by now???
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Still the most affordable 4 place option even with these issues. Got a hell of a deal on mine because it had the -5 blades on it. Even after replacing them in a few months I'll be way ahead of the game capital cost-wise. If you can afford to own and fly a more capable aircraft than an R44 more power to you, but I can't.
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Still the most affordable 4 place option even with these issues. Got a hell of a deal on mine because it had the -5 blades on it. Even after replacing them in a few months I'll be way ahead of the game capital cost-wise. If you can afford to own and fly a more capable aircraft than an R44 more power to you, but I can't.
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RHC issued these Service Letters last week.
https://robinsonheli.com/wp-content/...7/r44_sl70.pdf
https://robinsonheli.com/wp-content/...7/r44_sl68.pdf
As a result, I suspect we are going to see more reports of problems with corrosion, debonding, delamination, call it what you will.
Best Regards
Rich B
https://robinsonheli.com/wp-content/...7/r44_sl70.pdf
https://robinsonheli.com/wp-content/...7/r44_sl68.pdf
As a result, I suspect we are going to see more reports of problems with corrosion, debonding, delamination, call it what you will.
Best Regards
Rich B