Has a NTSB Final been issued for N123SX?

[WaiexN143NM]

Hi all,
Ive reread the accident ntsb reports initial, factual, final. And all the comments on this thread. It's too bad that a determination as to how this transpired was not found. . There are alot of experienced people in our community. Since the cause couldnt be determined, then good thought out comments need to be presented. The end result is never for a similiar event to occur.
My questions to this event:
1) what was the fuel status of N123SX. ? It flew for approx an hour back from dekalb il. , then prior (local) to accident an hour? So lets say 6 gal hour fuel burn. Approx 12 gal, leaving approx 4 gal.in tank?
2) maybe this event is a few items . Why no compression in the front cylinders via the valves. The right side possibly the valves not seating because they got bent during the impact and rocker box knocked off.
3) jeremy was a smart guy, and comfortable flying this aircraft. The mixture knob, pulled back in flight to try to get engine running better. Or possibly he pulled it back before impact so that it wouldnt drip after the accident , to mitigate a fire.
4)The turbo reported tested 25 hrs test cell. 75 hrs at time of accident. 25 hrs jeremy flying in approx a year from install and joes round trip to florida 25 hrs. Its experimental so the buyer determines if this is vetted.
5) 1700 ft takeoff roll. I cant believe it was on the ground this long without a rejected takeoff. Maybe, more plausable is lift off and in ground effect, and the chain of events started.
6) turbo not spinning and engine not rotating at impact. Hmm.... Dont turbos spin a high rpm and keep spinning after engine shutdown for a little bit ?
7) cause of white smoke. Did the crack in turbo bearing housing happen before or after impact? Joes last statement was the ntsb determined the crack was impact created. So more mystery here to the smoke trail.
8) weve discussed the intersection takeoff. As a pilot(40 yrs) and atc for 33 yrs, theres nothing like altitude airspeed and runway , fuel and good weather. Make your decesions , and risk you are willing to take.
9) SB issued on turbo . Clocking, and different oil. Could the accident aircraft experience coking on departure roll? Siezed turbo? Joe said they didnt find any evidence of this.
10 joe, thanks for your work at sonex, we all wish you the best. I know this event and work with the faa and ntsb , especially right after june 2 crash must have been difficult for you. Your 2 friends, coworker and boss were killed. I saw your flying the onex in the afternoon at osh as a tribute to jeremy, very moving.
11) since no exact cause was determined, good insightful knowledgeable comments are warrented.
12) lets be nice to each other. There's alot of passion here. Wether its turbo/aerovee owners, sonex owners pilots , factory personnel, interested people.
13) RIP to mike and jeremy.

WaiexN143NM
Michael

[lpaaruule]

If it weren't for the white smoke, I would be more willing to dismiss the engine and turbo from being the cause of the loss of power. But that aside, just off the top of my head you have:
1)induction
a)restriction - not likely an issue as it's just a filter on the carb.
b)ice - not likely as it's in 150F air
2)Ignition - This is a redundant system, so very unlikely that would be the cause, though I'm not too familiar with it.
3)Fuel system
a)Aeroinjector - found to be in working order, so not likely the cause
b)water - don't know
c)vapor lock - don't know. Jeremy talked about experimenting with Mogas, but that wasn't mentioned in the report.
d)debris blocking fuel flow - don't know

Joe is probably right, this is likely to remain a mystery. Without any further testing, and experimenting that's a certainty.

[Direct C51]

So what's the plan here? keep selling engines that have an unknown flaw? Keep offering transition training in a fleet that has seen like a 25% failure rate? Forget about the B model, the jet, and any future projects. Shouldn't figuring out the flaw in your current product be absolutely paramount? It's not like this is a crank failure that has been identified and addressed. It's an unknown flaw and every Arrovee is possibly susceptible. Am I wrong in thinking this?

[rick9mjn]

Thanks Joe ,THANKS ,thanks Joe,. many, many times over . For putting out your information and thoughts....i once had to clean up a fellow coworkers desk/workbench, after they has passed on.
So I know how painful some of this talk / web conversation can be.........
So please forgive us fools for saying / typing the wrong or painful things, Us “”fool's”” are just trying to get to be a little bit smarter and safer , and that is sometimes painful for everyone ..
Good day ,rick

[jjbardell]

Joe,
Can you clarify the notes from the NTSB on the mixture and the fuel level at all? I know, for me, it is hard to understand in the report. I am questioning the fuel amount estimated to be in the tank at time of departure. Was the 1 hr of flying Jeremy did after the fuel stop in DeKalb in another plane, or 123SX? Just curious.

All,
I once had white smoke puff out of my engine (witness on the ground saw it). I made the mistake that many have done before...I forgot to use my checklist and the mixture was still pulled out for taxi. Never went without a checklist since. I only caught it because my EFIS has voice warning and started screaming at me in my headset (Warning: CHT temp 425...Caution: EGT temp 1,400). It was amazing how a loaded plane could skyrocket temps before I could even hit 500 agl. It only took me a second to see the mistake and slam the mixture in and push the nose down to maximize airspeed. It happens.

As Joe said, we may never know. Any and all flying is a risk, flying Experimental is riskier. "Flying is dangerous. Either accept the risk, or stay the #uck on the ground"...as quote by my former Tomcat instructor. I'll never forget that.

As for the runway, I hate to see the comments that state there is no need to use all the runway because the aircraft is capable of less. Use all available runway. If you have a 1,700 ft roll, you still have time to throttle back and brake. If you get airborne, you have time to land and stop before the end of the runway. I don't care what the plane "can and can't do". Plan for the worst case and you leave yourself a lot more options. It's like trying to fly a long cross-country VFR and not use flight following. ALWAYS use every tool in your toolbox to fly safe. You don't get much forgiveness at altitude, and a few extra minutes here and there is a lot better than the alternative.

I am curious as to why the group thinks the Aerovee is so unreliable. It has it's issues, but so does so many other engines. No engines are perfect, not even a Lycoming. Remember when, not so long ago CASA banned Jab engines from night flying: Here's to refresh your mind:

The Civil Aviation Safety Authority (CASA) has imposed restrictions on planes that use a Queensland-made engine.

Last month, CASA launched an investigation into engines made by Jabiru Aircraft and Engines Australia in Bundaberg in southern Queensland after reports of more than 45 engine failures this year.

Article link: http://www.abc.net.au/news/2014-12-23/c ... ht/5985562

Yep, 45 in one year.

I've had my fair share of issues with the engine, and I am not a "Pro Sonex" guy. (Although a free B-model kit could change that for me...LMAO :)). I had my choice of engines when I bought my used kit. I could have put on a UL, Jab or any other engine. I chose the Aerovee Turbo because the value / cost was great compared to others. Looking back, I would still do the same thing today.

I think the biggest disservice we are doing as a group to the Sonex brand is casting so much negativity out there. We, as a community, can either sink the brand and all see our values plummet, the brand collapse, people lose their jobs, or continue flying and do your airframe/engine inspections to the best you can so each flight is safe.

It makes me sad seeing everyone writing so many negative things about this tragic accident. We are all one community. Discussion is good, I love the discussions and jump in many of them myself. Negativity, blame and accusations are a disease and spread like the plague. Potential buyers and current builders are all reading these posts. They form perceptions about our little community and the company. We are win or lose in this together.

Peace, love and all that $hit. #soapbox. Now, feel free to light me up...

[daleandee]

I too am disappointed that they were not able to find a specific cause for the apparent engine failure. There was no evidence that they could base any opinions on. Mechanically, everything was normal (other than impact damage). Unfortunately, this will continue to be a mystery.

Joe ... don't say "they were not able to find a specific cause" but rather "We" as in you also as you were part of the team.

You could not find an answer and come here and make statements that contradict what the report itself is saying. I'm not blaming the turbo but if I were a betting man that's where I'd win my share.

It's not possible that everything was fine yet the plane is destroyed and two lives are lost. Others have asked if the factory were going to make any statement on this. They should. I'm not suggesting that anything is being hid but there is no doubt that the people that assemble, fly, test, and maintain these engines everyday of the week have a pretty good idea of what the cause was. I know they do not want to be guilty of speculation and/or putting out information that would damage the brand but in reality by the lack of clarity being given damaging the brand is exactly what is happening.

Again ... you were part of this investigative team. You are partly responsible to provide an answer. What is your thoughts? Surely you have them. No one is holding your or anyone's opinion as fact. Yet there is no doubt more that can be known. Has the factory engaged in private testing to see if they can determine the cause of the crash? Pretty clear it was a power failure. If everything is fine and nothing was faulty before the crash then we are left with either it ran out of fuel (it didn't) or Jeremy pulled the engine to idle cut off for unknown reasons (he didn't).

Help us out here ...

Dale
N319WF

[radfordc]

So what's the plan here? keep selling engines that have an unknown flaw? Keep offering transition training in a fleet that has seen like a 25% failure rate? Forget about the B model, the jet, and any future projects. Shouldn't figuring out the flaw in your current product be absolutely paramount? It's not like this is a crank failure that has been identified and addressed. It's an unknown flaw and every Arrovee is possibly susceptible. Am I wrong in thinking this?

The Aerovee is a VW engine. VW engines have been modified for aviation use for going on 70 years or so. Lots of VW aviation engines have failed...with and without turbocharging.

Your suggestion seems to be to stop selling the Aerovee engine? What about alternatives? The Jabiru has had it's share of troubles and failures. The Corvair engine is noted for breaking crankshafts...at least they once were. Name an engine and someone has had a failure....Lycoming and Continental included.

Experimental aviation is a different breed of cat. You are the manufacturer and certify that the plane is airworthy. If you're not up to that then Cessna and Piper have some nice offerings.

[SonexN76ET]

Since the NTSB has not been able to determine the cause of the engine failure, perhaps we should look at possible (not probable) scenarios based on the information in the NTSB report. The possible scenarios are not to cast blame but to rather allow us to explore and analyze possible causes for the loss of power and to develop countermeasures to ensure that the possibility can be eliminated from the Aerovee powered fleet by the adoption of these countermeasures. Here are four example scenarios that I have come up with from reading the NTSB report, my experience with engines, my experience with the Aerovee, and the accounts and comments written about by others on this forum and others. Please feel free to comment and criticize as appropriate. The goal here is to ensure that engine failures such as this do not happen again.

Scenario One: The pilot of the aircraft leans the mixture excessively during taxi to prevent the valves and spark plugs from developing lead and carbon fouling and fails to set the mixture to full rich or near full rich for takeoff. On the take off roll the engine runs and produces whitish smoke from the exhaust due to the excessively lean mixture. Upon rotation and an increase in manifold pressure and rpm the engine can no longer run at the current mixture setting and the engine quits running.

Scenario Two: The pilot has planned a short flight and it is a warm day so he plans for a flight with the minimum required fuel. There are five or six gallons of fuel on board. The engine has been running a little rich so the pilot leans the mixture somewhat for takeoff. The pilot keeps the plane in ground effect for the first 1700 feet of the takeoff and then pulls up into a climb attitude a little steeper than normal. Because of the minimum fuel and the rapid change in pitch attitude the fuel pressure decreases and not enough fuel is delivered to the engine and the engine looses power and or vapor lock occurs.

Scenario Three: The turbo suffers coking issues as described in the Sonex airworthiness bulletin. The turbo does not spin up during the takeoff run causing the engine to produce insufficient power to have a normal takeoff run and is unable to maintain a climb and or to then maintain altitude. The pilot attempts to lean the mixture to gain a little more power from the engine. Unable to gain additional power, the pilot pulls the mixture to lean cutoff in preparation for an off field landing.

Scenario Four: Something in the induction or fuel system comes loose and causes a leak bad enough to prevent the engine from developing full power. Due to impact damage, it is impossible to determine if the component had become loose prior to the crash. Or, likewise, one of the engine controls, mixture or throttle has come loose or binds or will not achieve the proper full power position required for takeoff.

I am sure others of you have other scenarios you have thought about. No aircraft engine is 100% reliable. We all need to be prepared for an engine failure on takeoff no matter what we are flying. You do not have to be a Bob Hoover to survive an engine failure in a Sonex. You have to remember that these things stall at less than 40 mph. That is not much faster than the stall on a Quicksilver or Weedhopper ultralight. Keep the plane at best glide speed, choose your landing point and then land. Promise yourself you will not attempt the impossible turn. Train your brain and train your muscles not to do the impossible turn. On takeoff, tell yourself what you are going to do if the engine fails until say about 800 feet where you then have enough altitude to make a safe turn back toward the airport. I love all you guys and don't want to see anyone hurt again. Let's learn what we can from those who went before us and take the appropriate measures to mitigate those potential risks.

Jake

[Sonerai13]

1) what was the fuel status of N123SX. ? It flew for approx an hour back from dekalb il. , then prior (local) to accident an hour? So lets say 6 gal hour fuel burn. Approx 12 gal, leaving approx 4 gal.in tank?

There was about 10 gallons onboard. I checked the fuel myself as we were pushing the airplane out for the flight that day.

2) maybe this event is a few items . Why no compression in the front cylinders via the valves. The right side possibly the valves not seating because they got bent during the impact and rocker box knocked off.

There was physical damage that wasn't allowing the valves to close on the front cylinders.

8) We've discussed the intersection takeoff. As a pilot(40 yrs) and atc for 33 yrs, there's nothing like altitude airspeed and runway, fuel and good weather. Make your decisions , and risk you are willing to take.

Amen! Intersection takeoffs are done all the time, but they are not without risk. This is not the only accident that could have been mitigated had the pilot used all the available runway. We, as pilots, make decisions every day in our flying, and we must deal with the consequences of those decisions.

10 joe, thanks for your work at sonex, we all wish you the best. I know this event and work with the faa and ntsb , especially right after june 2 crash must have been difficult for you. Your 2 friends, coworker and boss were killed. I saw your flying the onex in the afternoon at osh as a tribute to jeremy, very moving.

Thank you.

13) RIP to mike and jeremy.

Indeed.

[Sonerai13]

Joe ... don't say "they were not able to find a specific cause" but rather "We" as in you also as you were part of the team.

I was part of the fact-finding team, and had input into the factual report. (Some of which I do not specifically agree with, even after giving my input.) I was not part of the NTSB headquarters panel that took the factual report and issued probable cause determination. I am only reporting what I saw during the physical inspection of the wreckage. I do not make any claim to doing any analysis or cause determination.

You could not find an answer and come here and make statements that contradict what the report itself is saying. I'm not blaming the turbo but if I were a betting man that's where I'd win my share.

I am going to say this one more time, and that's the last you'll hear from me; We did not find any physical evidence of a turbocharger failure, either partial or complete. I can not be any clearer than that. If you are not willing to accept my "eye witness" report of these facts, that's your problem, not mine.

Again ... you were part of this investigative team. You are partly responsible to provide an answer.

I can only report what I saw. I an not "responsible" for anything other than that. I am not going to speculate as to what may or may not have happened, as I didn't witness the actual takeoff and only saw the airplane the next day after it had been relocated to a secure hangar. I'm sorry if that is not enough for you.