Let me start out by stating that no exhaust system can be totally immune from cracking. We have over 4300 exhausts out there flying worldwide in all manner of environments and I can assure that the problem rate with our exhaust systems is a much lower rate than the "typical" exhaust. When careful attention and compliance with our mandatory instructions to lubricate the built-in slip-joints (one of the features to defeat stress and therefore cracks) is done and noted in the logbooks at each annual and if the propeller is within normal vibration limits, then that rate becomes even lower. If someone can show me the evidence that all things were truly as they state and show that it was installed per our instructions then we will take care of them. Full stop.
Without knowing the specifics of the cases you cite, it is difficult to truly address.
We fully back the exhaust with a 2 year/500 hour warranty if it is installed and the propeller is dynamically balanced.
The exhaust system was adopted by Diamond aircraft on two different brand new aircraft models and since has shipped over 500 units. We have multiple customers who have purchased a Power Flow for their aircraft, later sold the plane and then bought another aircraft and came back to us for another Power Flow for that model. If we really had a problem that is a significant as is inferred in your email, why would we have aircraft manufacturer's adopt our exhaust or have repeat business?
The Maule exhaust system has not only 4 independent slip joints (one per cylinder) but will also have 2 ball joints for the muffler/tailpipe so allow as isolation from both engine vibration and airframe interaction as possible.
Our 15 years of dedicated focus and expertise in exhaust design gives us high confidence that the Maule exhaust will be as durable or even more durable than any of our other products and we will stand behind it.
MAU MAU wrote: In talking to Dawley and my IA, your Power Flow exhaust's still crack and have to be repaired just like the antiquated Maule system. I even looked at one of your systems installed on a Cessna Cardinal that had a long crack that needed to be sent out and repaired and they followed your maintenance schedule to the letter.
My initial interest in your system was to avoid the aggravation and expense of continually dealing with cracks, but yours appears to crack as well.
Could you please address the cracking issue, and are you making any changes that could lessen the possibility.
I really want to see you guys succeed with a better option for us Maule drivers, but until the cracking issue is fixed I have zero incentive to purchase a Power Flow System.
Thanking you in advance................Rob