Tweet
I am posting this article to highlight the appauling attitude taken by Robbe UK when I had cause to return a faulty Align 91 helicopter engine to them. I would be interested to hear from anyone who has any comments about my saga or if they have any similar problems.
A copy of all emails between myself and my local supplier are attached as a PDF. The photos of the damaged engine parts are also attached.
For a full run-down of how Robbe denied all liability of faulty parts, you will need to read all of the attached PDF, but basically Robbe UK insist that the damage to my engine was caused by lack of lubrication and not a faulty ball bearing.
The story starts on a sunny afternoon at my local helicopter flying club. My helicopter engine has temperature sensors fitted to the cylinder head and exhaust. These are connected to my Jeti 2.4GHz receiver, which sends the temperature readings back to my transmitter, where I can see them in real time. This weekend was unusually warm and I was finding that both the engine and exhaust were running hotter than normal (but not excessively hot), so I was gradually adjusting the mixture after each flight by making it slightly richer.
Suddenly, while flying, the engine cut, so I auto'd down and landed safely. I took the helicopter back to the pits and tried to restart it, but it wouldn't start. It felt like there was less compression than usual. Later that day, when I got home, I took the engine out of the helicopter and stripped it down. I could see immediately why the engine had been getting hotter and why it eventually failed. All internal parts of the engine had small metal fragments imbedded in them, there were two places on the skirt of the piston that were missing and there was a large object that was stuck in one of the ports. This object eventually came free with a bit of persuasion, but at first I could not work out what it was. After removing the rear crankshaft bearing, I could see that it was part of one of the ball bearings. Clearly, the ball bearing had broken and part of it had bounced around inside the crankcase. This had broken two chunks of the piston skirt off, which disintegrated into small fragments. It was these fragments which had become embedded in all internal parts of the crankcase and combustion chamber. The severe scoring of the piston liner and piston ring reduced the compression of the engine, eventually leading to complete failure.
As the helicopter and engine were only six months old and had never been mistreated, I took detailed photos of the damaged parts and emailed them to the supplier of the helicopter/engine combo (Hobby Hangar, Yeovil, UK). They contacted Robbe UK, who are the importers for Align helicopters, who replied and requested that the engine be sent to them after being put back together again.
After a rather long time (over two weeks), Robbe eventually emailed back and blamed the premature engine failure on lack of lubrication! This is absolutely incorrect. This engine has never been allowed to run lean. Even if it had run lean, I do not believe that this could cause one of the ball bearings to break off, leaving the remaing part of the bearing still secure in its cage.
The comparison between the attitudes of the retailer (Hobby Hangar) and the importer (Robbe UK) could not have been more contrasting. Hobby Hangar always responded to my emails very quickly, Robby UK were never in any hurry to reply to Hobby Hangar. Eventually, I requested that the engine be returned so that I could seek professional advice and take the matter up in court. Hobby Hangar contacted me to tell me that they had received a new engine from Robbe UK. However, when I went to the shop to get the refund on the engine that I had bought to get flying again, they told me that Robbe UK had not sent a new engine and that in fact, they were refunding me the money on my new engine as a gesture of good will. This obviously leaves Hobby Hangar out of pocket in what I believe is clearly a problem caused by faulty manufacture.
OS engines (who make the Align helicopter engines) have an extremely good name. Align also have a very good name. However, both OS and Align have been let down by Robbe UK, who I believe were not prepared to admit that the problem was caused by faulty parts.
A copy of all emails between myself and my local supplier are attached as a PDF. The photos of the damaged engine parts are also attached.
For a full run-down of how Robbe denied all liability of faulty parts, you will need to read all of the attached PDF, but basically Robbe UK insist that the damage to my engine was caused by lack of lubrication and not a faulty ball bearing.
The story starts on a sunny afternoon at my local helicopter flying club. My helicopter engine has temperature sensors fitted to the cylinder head and exhaust. These are connected to my Jeti 2.4GHz receiver, which sends the temperature readings back to my transmitter, where I can see them in real time. This weekend was unusually warm and I was finding that both the engine and exhaust were running hotter than normal (but not excessively hot), so I was gradually adjusting the mixture after each flight by making it slightly richer.
Suddenly, while flying, the engine cut, so I auto'd down and landed safely. I took the helicopter back to the pits and tried to restart it, but it wouldn't start. It felt like there was less compression than usual. Later that day, when I got home, I took the engine out of the helicopter and stripped it down. I could see immediately why the engine had been getting hotter and why it eventually failed. All internal parts of the engine had small metal fragments imbedded in them, there were two places on the skirt of the piston that were missing and there was a large object that was stuck in one of the ports. This object eventually came free with a bit of persuasion, but at first I could not work out what it was. After removing the rear crankshaft bearing, I could see that it was part of one of the ball bearings. Clearly, the ball bearing had broken and part of it had bounced around inside the crankcase. This had broken two chunks of the piston skirt off, which disintegrated into small fragments. It was these fragments which had become embedded in all internal parts of the crankcase and combustion chamber. The severe scoring of the piston liner and piston ring reduced the compression of the engine, eventually leading to complete failure.
As the helicopter and engine were only six months old and had never been mistreated, I took detailed photos of the damaged parts and emailed them to the supplier of the helicopter/engine combo (Hobby Hangar, Yeovil, UK). They contacted Robbe UK, who are the importers for Align helicopters, who replied and requested that the engine be sent to them after being put back together again.
After a rather long time (over two weeks), Robbe eventually emailed back and blamed the premature engine failure on lack of lubrication! This is absolutely incorrect. This engine has never been allowed to run lean. Even if it had run lean, I do not believe that this could cause one of the ball bearings to break off, leaving the remaing part of the bearing still secure in its cage.
The comparison between the attitudes of the retailer (Hobby Hangar) and the importer (Robbe UK) could not have been more contrasting. Hobby Hangar always responded to my emails very quickly, Robby UK were never in any hurry to reply to Hobby Hangar. Eventually, I requested that the engine be returned so that I could seek professional advice and take the matter up in court. Hobby Hangar contacted me to tell me that they had received a new engine from Robbe UK. However, when I went to the shop to get the refund on the engine that I had bought to get flying again, they told me that Robbe UK had not sent a new engine and that in fact, they were refunding me the money on my new engine as a gesture of good will. This obviously leaves Hobby Hangar out of pocket in what I believe is clearly a problem caused by faulty manufacture.
OS engines (who make the Align helicopter engines) have an extremely good name. Align also have a very good name. However, both OS and Align have been let down by Robbe UK, who I believe were not prepared to admit that the problem was caused by faulty parts.
Comment