Has a NTSB Final been issued for N123SX?

[andrewp]

Dale,

The damage to the turbo was caused by the crash impact forces, and only after the crash the turbo wouldn't rotate. The investigation notes and pictures of the turbo show that the damage to the housing was caused by the impeller wheel impacting it during the crash. The turbo would not rotate simply because it was damaged in the crash! The rest of the investigation showed no pre-impact turbo anomalies. The NTSB report could have been much better here, and Joe is trying to clear up any misunderstandings.

I see you edited your original to make it nicer. I appreciate that.

For everyone concerned I'm gonna leave this alone as it's apparent that regardless of the facts of the NTSB report (trust me there are more concerning questions I have) there seems to be a great resistance to acually reading the NTSB report and speaking to what is there.

No doubt an answer won't be found but when the well known, long time members of this community start professing truths that are contrary to the stated facts of the report ... I'm done. I refuse to seek answers from those that aren't willing to search for them.

Dale
N319WF

Seriously? I personally have great resistance to folks who say things like the above. I assume you feel a little better now for that, or are reading a guide book on trolling or something. This has been one pretty badly behaved thread since last time I looked at it.

[Sonerai13]

Ok folks, I'm going to offer these last comments and then I'm going to end my participation in this thread. I don't need to be reliving this every day during these discussions. I've had it.

RE: the turbo

I do not agree with the NTSB's choice of words regarding the description of what we found during the initial investigation. I was allowed to see a "draft" copy of the factual report before it was published, and I offered alternate wording that was more in line with what I personally found during the investigation. While they did change the wording somewhat from what they had originally suggested, they still did not convey the exact facts as I found them. I can say with 100% certainty that there was no evidence of any anomalies or abnormalities to the turbo, other than the impact damage. I am not directly involved anymore, but I would hope that Sonex is pursuing some sort of correction to this, as I feel that the NTSB reports are not completely correct.

RE: Smoke system

The smoke system was removed from the airplane when the turbo engine was installed. The switch remained in the panel, but it wasn't connected to anything. The rest of the system was removed.

RE: The engine

During the initial phase of the investigation, the day after the accident, the engine was only disassembled to the point where we could verify mechanical continuity. The crank was found to be sound, the valve train was intact, and the only issues discovered at that time were due impact damage.

Subsequently, the engine was moved to the shop at Sonex and was completely disassembled, right down to the last nut and bolt. Every part was checked internally and externally. This includes the turbo (which had already been to the NTSB lab and back by then). Again, no mechanical problems were discovered, other than the impact damage.

The accident turbo wastegate controller was installed on the engine in the Sonex test cell and was run to check for function. It functioned perfectly. We also tried to induce various failure modes to the engine in hopes of getting it to produce a puff of white smoke. We were not successful.

I don't know what else I can say. I've said most of this more than once already. I will not continue to debate this with anyone, as I have covered the details as I know them firsthand, and I cannot add any more to the discussion than that. I hope all of you can appreciate my position.

[lpaaruule]

Thanks Joe.

I noticed that you addressed the removal of the smoke system a month ago on this thread. I had done a quick search in the official report, and didn't see that fact there, maybe I just missed it. Sorry for muddying the water, I try to be accurate with posts.

Perhaps all we can do is as you say, "hope that Sonex is pursuing some sort of correction to this".

[kmacht]

Let's not turn this thread into personal attacks, especially on Joe. He has been far more accommodating and forthcoming on what he knows about the accident and investigation than anybody else from the factory has been. He has his facts and experiences and the ntsb has theirs. You shouldn't discount what either of them are saying even if they differ fron each other. The facts arent different but the conclusions drawn are as they are seen through two different sets of eyes with different experience to draw upon.

To keep this thread moving in a positive direction I would like to pose this question to the group. Has anyone else experienced white puffs of smoke from their engine? If so, what were the circumstances behind it? Any reports of white puffs from ground observers while experiencing the "sonex burps"? How about with water in the fuel at startup?

If we ever get someone from the factory on here I would like to also know more about the fuel system. Was the finger strainer in the tank looked at during the investigation? Any contamination at all found in the fuel tank? Did it have a gascolator or a fuel filter? I experienced a Princeton fuel probe corrode to the point it broke off inside the tank when sitting in mogas or a year between first engine run and first flight. It plugged up the finger screen enough that I had to remove and replace it.

Second, what type of mixture control was installed. Was it a pushbutton lock or friction lock? This would provide some insight as to if the mixture was intentionally pulled in flight or maybe moved during the impact.

Finally, was the position of the aero carb needle confirmed to be close to where it should be? The report notes orientation and flow but doesn't mention if the setscrew was still locked or if the needle was too far in or out for normal operation. I have experienced problems getting my set screw to hold the needle in place when doing adjustments and always worried about it slowly migrating during flight from the engine vibration.

Keith
#554

[andrewp]

Joe:

Thank you so much for going to the trouble of sharing all of this. And well done for being a party to the investigation. And thank you for teaching me how to land my Sonex before I had flown it. I had a really awesome time back in 2013 and I know you have helped a lot of others since then (actually I think I was the t-flight practice guy? ... whatever I enjoyed the heck out of it).

The Sonex is an fantastic little plane and puts a smile on my face everytime I fly it. Again, all the best over in EAA land.

Cheers,

Andrew
Sonex 618
1962 Cessna 182E

[Sonerai13]

Keith,

I will answer your questions, just to avoid more speculation.

Was the finger strainer in the tank looked at during the investigation?

Yes, the strainer was checked and it was clear.

Any contamination at all found in the fuel tank?

No. A fuel sample was taken and found to be clean.

Did it have a gascolator or a fuel filter?

No.

Second, what type of mixture control was installed. Was it a push button lock or friction lock?

Neither. It was a "choke cable" from a local auto part store. There was no lock or friction mechanism on the mixture control.

Finally, was the position of the aero carb needle confirmed to be close to where it should be?

The set screw was in place and tight.

[Sonerai13]

And thank you for teaching me how to land my Sonex before I had flown it. I had a really awesome time back in 2013 and I know you have helped a lot of others since then (actually I think I was the t-flight practice guy? ... whatever I enjoyed the heck out of it).

Andrew,

Thanks for the kind words. Much appreciated. And yes, you were one of the "prototype" T-Flight customers. While we were helping you, you were helping us refine the program. Thanks for that!

[sonex1374]

Joe,

You have been extremely gracious during this entire process, and I deeply appreciate your involvement and input. It's not easy standing in the line of fire, but I'm glad you're up to the task.

Jeff

[markschaible]

Hello SonexBuilders.net,

On the morning of January 12, 2016, immediately after reading the final report issued at midnight on January 11th, I sent the following message to Jason Aguilera, Investigator In Charge (IIC) for this investigation:

Hello Jason,

I would like to formally object to the statement in the report’s “Analysis” section -- paragraph 2, sentence 5: “It could not be determined whether the turbocharger would not rotate due to impact damage or whether it seized in flight resulting in a partial loss of engine power.”

According to statements by Joe Norris, he reports that, with your oversight when examining the turbocharger before it was sent to the NTSB laboratory, the impact damaged portion of the turbocharger housing was removed, and the turbine shaft was found to be rotating freely once pressure from the impact-damaged section was removed from the turbine. Joe’s account of the initial turbocharger examination directly conflicts with the statement in Factual Report section “Wreckage and Impact Information” paragraph 5, stating that disassembly was halted after finding a crack in the housing, and this bears clarification. I’ve copied Joe on this email and would like for you both to communicate about the actual sequence of events.

Factual Report section “Tests and Research” paragraph 2 also states that “Both the compressor wheel and turbine wheel turned together freely within the center housing when either was rotated by hand.” This statement also conflicts with the mischaracterization of the “Analysis” section of the report, paragraph 2, sentence 5 as quoted above.

What is our process for clearing these items up in the report?

Thanks,
-Mark

Jason is taking the matter up with his management at NTSB to determine how to proceed.

The fact of the turbocharger’s free rotation after removal of the impact-damaged turbine housing was discussed at-length here at Sonex before the turbocharger ever came back from the NTSB lab, so we are certain that Joe’s account of the chain of events in the investigation per my message above is accurate. Also note that all parts from the accident aircraft were kept in a sterile chain of custody per NTSB procedures and Sonex Aircraft representatives were only able to access and examine these parts under the supervision of the NTSB, usually accompanied by FAA representatives as-well.

As Joe has remarked, the engine and turbocharger were fully disassembled and examined by Sonex aircraft and two NTSB investigators, along with two FAA representatives. The lack of physical evidence suggesting a root cause of the accident gives the NTSB and Sonex Aircraft no direction in-which to focus further investigative efforts. NOBODY wants to know what happened more than us. But unfortunately, that just isn’t possible to ascertain at this time. I can assure you that every theory and point of due diligence discussed in this thread, and more, have been pursued in this investigation. It's also worth noting that although Joe was the Sonex Aircraft lead for these efforts, John Monnett and other Sonex Aircraft staff members have been heavily involved throughout the process, including the disassembly and examination of the turbocharger, engine, and test stand running of the accident wastegate on our exemplar engine. There were many sets of eyes on these parts throughout the investigation. There's not one of us here that doesn't relive June 2nd 2015 on a daily basis, and that doesn't try to mentally put ourselves in that cockpit and divine missing pieces of the puzzle. That mental exercise will likely haunt us forever.

Aside from our formal objection to the investigation’s analysis details, as copied above, there’s nothing we can add to the NTSB final report, accident docket materials, or to this discussion thread that will satisfy many of you in this forum. As we have done for years with both airframes and engines via our existing service bulletin systems, all we can do going forward is to address issues that can be positively identified by physical evidence. While we believe strongly that there must have been a mechanical root cause to this accident, we have no data pointing to that cause, or to a condition that would threaten the worldwide fleet at-large.

As-difficult as it may be for many of you to accept, we cannot ignore the many thousands of successful fleet hours flown on AeroVee engines of all types, including AeroVee Turbo engines, flown around the globe before and since June 2, 2015. Our mission and our pledge is to continue offering and supporting the AeroVee product line actively, in the most responsible manner possible.

I know that many of you will say that, likewise, we cannot ignore two factory fleet accidents within 14 months’ time, however, we can only act upon data gleaned from the investigations of those accidents, and at this point, we have no data that supports action.

We would like to once again publicly thank Joe Norris for his work on this most difficult and frustrating of investigation processes as our designated representative to the NTSB, and for his willingness to respond to posts on this thread with his first-hand information about the facts and events of this investigation. Coming-up empty on this investigation pains each and every one of us and our families at Sonex Aircraft more than words can describe.

--
Mark Schaible
General Manager
Sonex Aircraft, LLC
phone: 920-231-8297
fax: 920-426-8333
http://www.SonexAircraft.com
http://www.AeroConversions.com

Sales Info: sales@sonexaircraft.com
Orders: orders@sonexaircraft.com
Accounting: accounting@sonexaircraft.com
Tech Support: tech@sonexaircraft.com

[NWade]

Thank you, Mark & Joe, for remaining cool-headed in this thread. I can only imagine how difficult that is, given the personal loss you suffered.

To the folks who will undoubtedly continue to post on this thread: Please review your posts before you hit "Submit". Ask yourself whether you would say the same things out-loud to someone's face - especially someone who has lost a friend or family-member. And remember that Sonex is a small company with just a handful of employees. This is not a big corporate enterprise with a Shareholders and millionaire Executives who are trying to protect their fortunes and obfuscate the truth. Its easy to fall into that mode of thinking/suspicion in our current society, but it serves no purpose here. Sonex has not been afraid to release updated parts and procedures for all of their products, as they figure out new and better ways of doing things - just look at their website to see their track record of this over the last several years. They're not perfect (and they don't claim to be); but they haven't done anything to justify suspicion of their motives or integrity.

Finally, to anyone who is concerned about the "failure rate" of engines, please go spend some time reading forums & NTSB reports for RVs, Zeniths, Rutan Canards, and other homebuilts. An aircraft engine can fail for any number of reasons: mechanical problems, fuel system failures, electrical issues, etc. And the skill and attention to detail for each of these systems is up to the individual builder. Therefore you're going to find a wide variety of problems; Sonex is not out of line with any other brand in the industry. These accidents may stand out strongly in your mind, but that's because you are invested in the brand both financially and emotionally. Its the same effect as non-pilots seeing Airline accidents and becoming fearful of airline safety: its an emotive response that facts do not support - when you take the time to distance yourself from the subject and then look at the numbers in an objective fashion. The best thing you can do to ensure your safety in any homebuilt aircraft is to take your time and do everything right (and re-do anything that's not right). Then test the aircraft carefully and fly it conservatively. Hundreds of Sonex owners have done this for thousands of cumulative flight-hours.

Take care,

--Noel
Sonex #1339