Has a NTSB Final been issued for N123SX?

[Sonerai13]

Also, the impeller would not spin at the accident site it wasn't until the folks in D.C. messed with it that it started spinning...

Ok, let me use this comment as a springboard for my input, as this is incorrect and needs to be cleared up.

I was there, in person, helping the FAA and NTSB inspect the aircraft the morning after the accident. I worked directly with FAA and NTSB personnel throughout this investigation. I ran the engine for them during the testing of the wastegate controller in the Sonex engine test cell. I was the one who took the turbo apart during that initial investigation the day after the accident. Here's what I saw.

The engine, including the exhaust and intake systems, incurred significant impact damage. The impact damage displaced both the exhaust and intake systems in such a way as to break the turbo casting right behind the large snap ring that holds the compressor housing to the central bearing block. This caused the compressor housing to contact the compressor wheel blades, which jammed the turbo (and which caused the marks that are described in the factual report). Immediately upon relieving the contact between the compressor housing and the compressor wheel, the shaft turned freely. This was before the turbo was removed from the hangar, let alone sent to the NTSB lab. That fact is not clearly spelled out in the wording of the factual report, but it is in fact what we found.

There was no smoke system on the airplane.

There will be a final report that follows, which will include any "probable cause" statements that the NTSB wishes to make.

The NTSB and FAA have been very thorough in their investigation. I, and others at Sonex, worked very closely with them throughout, making sure they had any and all information they needed. Please do not try to read more into the report than what is there. It reports the facts. It is very thorough and correct to the best of all our efforts. Please respect that and don't try to make it more than it is, or try to conclude something you wish was there, or hoped was there, or think is there. Just read the facts.

Thanks,

[Bruce593SX]

Thanks Joe, that's what I thought I read, but they seem to hint at impact damage, but not real clear. I appreciate the clarification.

[kmacht]

Joe,

Thanks for speaking up and providing some context. I think this is the first post from someone at the factory saying more than they can't comment due to the investigation. I think many (including myself) were hoping for something more conclusive in the report after waiting so long. That is probably why people are trying to read more into it than there may actually be.

I hope you understand the builders/owners position as well. There have been two factory aircraft that crashed with experienced pilots behind the controls due to engine issues. Alot of us are not at ease with the fact that the motors built at the factory (which should be the gold standard) are failing. It makes some of us uneasy flying behind our motors without a good explanation of why they failed and what if anything we can do to prevent it happening to us. We have been told to wait for the ntsb report to come out and now that it has it is providing more confusion than clarity.

Keith
#554

[Sonerai13]

I think this is the first post from someone at the factory saying more than they can't comment due to the investigation.

Please understand that we at Sonex were signed on as parties to the investigation, and as such were not allowed to comment on anything that hadn't been released to the public. That situation was just as frustrating for us as it was for you. Now that this factual report has been published, we can comment on the specifics that are included in the report.

[vwglenn]

This caused the compressor housing to contact the compressor wheel blades, which jammed the turbo...

There was no smoke system on the airplane.

There will be a final report that follows, which will include any "probable cause" statements that the NTSB wishes to make.

Thanks Joe. You're a great asset to us and the factory. I'm sure I speak for all of us when I say I'm thankful for your input on these boards.

Good to know that the only obvious damage to the turbo was impact damage. It also and goes to show that even the NTSB can write things up so they're misleading.

The fact that there was no smoke system on the plane eliminates a simple explanation. I suspected there wasn't one installed because they didn't mention it. However, I don't like to assume.

Don't hang your hats too hard on the NTSB's "probable cause" guys. It doesn't look like there is a smoking gun in the investigation so their cause will probably be something totally disappointing.

[dc75]

I didn't see anything about the integrity of the fuel system in the report, besides the aero injector flowed fuel when gas was added to the inlet.

I would never in a million years think the plane was empty, considering who the pilot was. But, they didn't mention it in the report?

[n982sx]

Because of the thread title I want to point out that this is just the factual report and not the final report.

No probable causes or contributing factors have been determined yet. The report does include a lot of information.

[gammaxy]

I didn't see anything about the integrity of the fuel system in the report, besides the aero injector flowed fuel when gas was added to the inlet.

There's more detailed information in the NTSB docket at:
http://dms.ntsb.gov/pubdms/search/hitli ... etID=59406

The Field Notes contain the following additional information about the fuel system:

The fuel tank had been separated and contained a residual amount of blue tinted fuel
consistent with 100LL.

The fuel tank was not relatively intact. The fuel filler cap was impact separated and the line from the bottom/rear of the tank was impact separated. The fuel level sensor probe remained attached to the tank; however the transmission wire was broken.

[floridasonex]

I didn't see any mention of testing the magnetos. My thinking was that if you had two similar degradation of power incidents one on a turbo powered plane and the other on a standard non turbo engine and there seems to be no other problems with the engine rotating freely or the fuel was proven to be reaching the cylinders, then I'd suspect something in the ignition system. This is just me thinking out loud and I have practically no experience.

I've had one ignition system fail and it ran pretty close to the same as with them both
operating

[WaiexN143NM]

Hi all,
A few things come to mind, if the ntsb does any more inquiry into this terrible event.
1). Fuel status of N123SX
2). What was cause of smoke trail behind aircraft.
3). No compression on front cylinders via the valves.
4). Mixture knob almost pulled full aft to cut off. Witness mark on shaft i would think from initial impact.
RIP jeremy and mike.
We have the stickers on our plane that dana designed. Thanks dana.
Happy holidays to the Monnett's, the Sonex staff, and all.
Be safe, fly safe

WaiexN143NM
Michael