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New exhaust wrecks FX-3?

frequent_flyer

Registered User
Arizona, USA
I periodically check the NTSB data base for FX-3 accidents. The total is now up to 13 with probably less than 130 in service. Does not look good for insurability. One recent accident report is really strange. A different exhaust system had been fitted and it disintegrated on the first test flight. Engine lost power and aircraft was substantially damaged in off airport landing. - NTSB WPR21LA250

Couple of questions:

1. What would be gained by replacing the factory standard 4 into 1 system? Quieter, more power, something else?
2. Report says new exhaust was titanium header and aluminum muffler. Accident flight photo seem to show an extended tail pipe. Anyone know what exhaust this was?
 
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My buddy is the DOM at Tac Aero and was the pilot. Just got off the phone with him. Customer had a glass pack, long swiss style muffler made by an aircraft exhaust company cause he didn't like the smell or the sound of the stock FX3 system. They installed the exhaust which had a titanium can to offset the weight of the long muffler. He got 900 to 1000 feet up and the prop stopped. The inner can which is perforated was rolled against the grain and cracked between the holes. The glass in the front of the muffler peeled aft and stopped up the tail end and shut off the exhaust. To quote him the tail pipe looked like a cat's ass.
 
I had been wondering about those Swiss mufflers. I thought glass surrounded the inner perforated tube. I'd like to see how it got packed into the tail pipe.
 
I don't think any of us can access your hard drive. ;)

NTSB seems to be making it much harder to give a direct link to a report. When you access the report from the NTSB site it downloads it rather than linking to it. That's why I only gave the report number in my initial post. It's easy enough to find with your favorite search engine.
 
I thought glass surrounded the inner perforated tube. I'd like to see how it got packed into the tail pipe.

Steve's report indicates the inner perforated tube broke up. It's probably bits of that inner tube that can be seen leaving the aircraft in the video still frame that's included in the NTSB report.
 
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Second report down, and yes, what frequent_flyer posted. The perforated tube was rolled against the grain by the manufacturer, cracked between the perforations and came apart allowing the fiberglass to peel back and clog the tail pipe. They had made multiple static runs before this first test flight. He put it between two apple trees ling one yard to the next. Clipped the tops and just had to replace some sheet metal in the wings and recover them. No substantial structural damage.
https://data.ntsb.gov/carol-main-public/query-builder?month=6&year=2021
 
Thanks for posting this. I am planning to do the same thing with my EX-3. The Sky Dynamics 4 into 1 exhaust is painfully loud. The megaphone exhaust outlet is supposed to provide a Conada effect to help scavenging, but I doubt it works at a 45 degree angle as installed. I had one for a while on my RV-8, and the noise level inside that echo chamber would blow away any ANR headset. I finally install a Veterman 4 pipe system (no collector or muffler) and it was much better.

I am planning to use a Burns Stainless muffler like I have used on a couple of race cars. They are expensive, but high quality, and I've never had one come apart or fail in any way.

John
 
I have a lot of time in the FX3 and never noticed it being loud, actually seems quiet to me. I am using a Bose headset though.
 
When testing new parts, is it not prudent to stay over the field in test flights?

Second report down, and yes, what frequent_flyer posted. The perforated tube was rolled against the grain by the manufacturer, cracked between the perforations and came apart allowing the fiberglass to peel back and clog the tail pipe. They had made multiple static runs before this first test flight. He put it between two apple trees ling one yard to the next. Clipped the tops and just had to replace some sheet metal in the wings and recover them. No substantial structural damage.
https://data.ntsb.gov/carol-main-public/query-builder?month=6&year=2021
 
So if the accident rate is 10% and the aircraft is roughly $200K, what kind of hull premiums do you think will be the norm? An experienced Cub driver I know is paying over $4 grand per yesr for hull coverage on an amphib Cub worth maybe $120K.

And how are these accidents happening? All ground loops on paved runways, or are they expensive off-airport mishaps?
 
So if the accident rate is 10% and the aircraft is roughly $200K, what kind of hull premiums do you think will be the norm? An experienced Cub driver I know is paying over $4 grand per yesr for hull coverage on an amphib Cub worth maybe $120K.

And how are these accidents happening? All ground loops on paved runways, or are they expensive off-airport mishaps?


Ummm, Bob....try doubling that hull value. Or close, at least.

MTV
 
What Mike said, FX3 is probably going for $360-400K. Had someone looking at an EX3 with 200hrs tt and no tailwheel $14k a year to insure. Surprised anyone would insure. You amphib SC is worth worth than $120k right now I would bet.
 
My cheap.exp. has 2200 hours on a Swiss muffler I made, I can only took it off for saving 6 pounds. No problems whatsoever!
 
I have a lot of time in the FX3 and never noticed it being loud, actually seems quiet to me. I am using a Bose headset though.

Try taking the Bose headset off. The FX-3 is deafeningly loud compared to my PA-28. The only aircraft I have ever flown that come close to being as loud as the FX-3 is the Husky. Lots of time in PA-18-180 and they were quiet in comparison.
 
And how are these accidents happening? All ground loops on paved runways, or are they expensive off-airport mishaps?

The reports for the most recent two FX-3 accidents have no narrative yet. I used ADS-B to check on one of them and it appears to be a departure off the left side of a long paved runway. In the mix are a forced landing due to engine failure (I think crankshaft), now an engine failure due to failed non-standard exhaust, another (from memory) hit trees with full flaps in a failed missed approach. The majority seem to be loss of control on paved runways. I have not seen an NTSB report for an accident while intentionally operating off airport. I suspect that some don't get reported.
 
Try taking the Bose headset off. The FX-3 is deafeningly loud compared to my PA-28. The only aircraft I have ever flown that come close to being as loud as the FX-3 is the Husky. Lots of time in PA-18-180 and they were quiet in comparison.

Ummmm—Airplanes=Noisy. If you think those planes are noisy, stay far, far away from Beavers……just sayin.

MTV
 
Is the accident rate due to the aircraft (which I doubt) or the pilot population that buys them? This reminds me of the forked tail doctor killer and then the Cirrus. Good airplanes, but highly motivated and successful owners who maybe don't have the time to get truly proficient. Steve Pierce's video on "Stuff happens" should be mandatory viewing. I mean no offense to any Cubcrafters owner, and frankly I don't know the reason for the accidents. Just worthless naked speculation.....
 
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