[Orv Neisingh]

I have an A600 Talon that the owner landed in a residential cul-de-sac and was reported to the FAA by a homeowner, he lost his license as a result and so parked the helicopter for about 7 years, it only had around 60 hours on it when it was parked. I recently got the job of bringing it back to airworthiness. I drained and purged the fuel system, lubricated all of the service points, drained and added fresh oil and filter, installed new elastomeric bearings, a new battery, and performed a few other maintenance items. The helicopter fired right up and ran smoothly so I lifted off solo and put about an hour of hover on it. 

Next I asked my 230# buddy to be my ballast weight to see how it flew with full fuel and at gross weight. As we brought the engine up to full RPM all was running smoothly, then I added collective and when we reached around 26" of MP the engine had a slight miss, it was no longer running perfectly smooth. I elected to keep it at that power setting to allow the SEA FOAM that I had added to the fuel to clean the injectors before we picked up. We ran at that power setting for about 3 minutes when all of a sudden the engine seized immediately. I was very happy that when this happened we were still firmly on the ground and there was no damage to the helicopter. Had it been at altitude then you never know how the auto will actually turn out. 

On Inspection once the engine cooled down I was able to rotate it about 15 degrees in either direction with a hard stop at each end. It appears that this engine was another one of those stock Rotorway engines that have experienced a broken crankshaft. The factory did not line bore the main bearing journals all the way through, they went from one end to the center then bored from the other end to the center often causing the journals to be out of line by several thousands of an inch. When the case is torqued around the new crankshaft that shaft is slightly bent and runs that way until if finally breaks at its weak point. Joe Huff has seen a number of these breaks as I have as well. The only solution is to install a properly designed crank as Joe does when he does his engine conversion on the reworked case that has been perfectly line bored by Joe. One of my own ships had a catastrophic engine failure at around 200 hours so I had Joe Huff build a great engine for me. 

So we have a complete A600 Talon with an engine core that either needs a replacement engine or have this one sent to Joe Huff for a complete conversion to the 172 engine. The owner does not want to put any more money into the helicopter so it would be a great buy for someone who wants to get a Talon with the Joe Huff engine conversion. 

If you are flying with a stock Rotorway engine you may have a well aligned crankshaft or you may have one that is fatiguing with each hour of flight. I now have three helicopters in my hangar that have experienced this catastrophic engine failure, two while at altitude and this on on the ground. Two are flying now thanks to Joe Huff, the third will be flying again for a new owner who wants to upgrade.

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[Tim Morris]

You have all the fun!

[Lyle Swallows]

yikes...

any ideas on how to find this before failure? i know its just a slight offset and bending that doesnt add a lot of vibration but the stress is immense on the hardened brittle crank...

you make it feel like a roll of the dice. of course it is with experimental helicopters.

Practice your auto's!!!

i had a lazy 3.2 hour flight yesterday to get a burger and i felt guilty because i didnt practice a single auto in that time...

[Orv Neisingh]

yikes...

any ideas on how to find this before failure? i know its just a slight offset and bending that doesnt add a lot of vibration but the stress is immense on the hardened brittle crank...

you make it feel like a roll of the dice. of course it is with experimental helicopters.

Practice your auto's!!!

i had a lazy 3.2 hour flight yesterday to get a burger and i felt guilty because i didnt practice a single auto in that time...

Hi Lyle, I don’t know how anyone would be able to tell if their engine crankshaft journals are in alignment without complete disassembly of the engine and removal of the crankshaft. Always fly over areas that you would like to safely auto into. I have been forced to perform 19 real to the ground emergency autos in my 40 years of flying Rotorway’s consisting of over 13,000 hours. Always be ready and cautious and if in doubt…auto out.

[Lyle Swallows]

with my engine currently removed for re-fitting body panels it begs the question is it worth getting the engine "blueprinted" for piece of mind. getting a reputable shop to -re hone the main journals in an appropriate manor.

i'm not sure freight shipping to Joe Huff is in my budget, nor a full Joe huff build.

[Orv Neisingh]

with my engine currently removed for re-fitting body panels it begs the question is it worth getting the engine "blueprinted" for piece of mind. getting a reputable shop to -re hone the main journals in an appropriate manor.

i'm not sure freight shipping to Joe Huff is in my budget, nor a full Joe huff build.

It certainly would give a load of peace of mind to know that your crankshaft is not going to catastrophically break if you have it checked. If you find that the journals are out of line then the crankshaft has already been damaged and should be red tagged.

[Orv Neisingh]

You have all the fun!

I suppose that is because I fly many more hours in these helicopters than most folks so I get exposed to more issues. We know the cause of these crank breaks but unfortunately the only way to certify the integrity of the crankshafts is to pull the engine apart and check the bore alignment of the main crank bearing journals. This is why Joe Huff line bores every case before installing his new 172 engine crankshaft.

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If you are flying with the stock Rotorway engine that has not been checked for the alignment of the crankshaft bearing journals, just use caution by always having an acceptable place to set down withing auto range as you fly. The crank break is not real common but in some of the engines that are flying it will happen, you just do not know when.

[Homer Bell]

I’m not an engine guy. But seems to me that as the bearings wear a slightly misaligned case will tend to fix itself. The longer it runs without failure, the better off you are. Of course it’s going to depend a lot on how misaligned it is to start with.
Over the years the crankshaft has been one area of the machine that has been pretty solid. Not many of them have failed. Valve train and burnt pistons are far more common. Four of my forced landings have been valve train issues. As we add more and more horse power and increase the loads on our 3 bearing crank. Joe’s new crank will help some with that.
It’s always good advice to fly over areas that can safely be autoed to. There are lots of other reasons that require getting on the ground quickly. We had an engine fire at John’s in May.

[Lyle Swallows]

was there ever a recommendation to run break-in mineral oil like is required on Lycoming engines? i agree with Homer, after the first 100-200 hours of runtime it shouldnt be a factor anymore, but those initial 50 hours are crucial to the health of the engine.