Sonex Accidents

Sonex Accidents

Posted: Thu Mar 19, 2015 12:32 pm

by johnr9q@yahoo.com

Sonex Accidents.pdf
(1.21 MiB) Downloaded 670 times

I was searching for information on Sonex accidents and wasn’t satisfied with the information supplied on the Sonex Pilots and Builders Foundation site so I spent the day, yesterday, compiling the attached list of all the accidents I could find involving Sonex and included all the data that I was interested in. I hope people on this site can add information I have not found, especially information on what the cause of an engine failure is. Also more information on what type of engine was in the aircraft that had an engine failure. Most of the time the information I obtained will state something like “aircraft lost power”. It would be nice to know why it lost power, did the crank break, etc. Where I state the “issue” whether it is Pilot error or Mech issue this was my determination based on the limited information I had. If any of you see this as incorrect please advise me so I can make changes. I don’t want to place blame where not appropriate. Also, I made a suggestion in the suggestion section on this forum, requesting that an accidents section be added. Thanks, John R


Re: Sonex Accidents

Posted: Thu Mar 19, 2015 4:49 pm

by radfordc

Here is the info on N229P crash in 2007:

NTSB Identification: DFW07CA068
The docket is stored in the Docket Management System (DMS). Please contact Records Management Division
Accident occurred Saturday, February 10, 2007 in Atlanta, TX
Probable Cause Approval Date: 05/29/2007
Aircraft: Fortuna Sonex, registration: N229P
Injuries: 1 Uninjured.

NTSB investigators used data provided by various entities, including, but not limited to, the Federal Aviation Administration and/or the operator and did not travel in support of this investigation to prepare this aircraft accident report.

The airplane stalled and collided with trees while maneuvering to avoid trees during a go-around. The pilot reported that while practicing takeoff and landings on runway 33, he determined that he was too high on the approach and initiated a go-around. The pilot concluded that his 80-horsepower homebuilt airplane was not going to be able to clear the trees at the departure end of the 2,463-foot long, by 150-foot wide turf runway, so he turned the airplane 45-degrees to the left to avoid the trees. The pilot added that while maneuvering, the airplane stalled and collided with trees located about 100 yards west of the runway 33. The airplane came to rest in the inverted position at the base of the trees, resulting in structural damage to the wings and the fuselage. The canopy was also damaged. There was no fire. The Federal Aviation Administration (FAA) inspector who responded to the accident site noted that runway 15/33 is not annotated on the airport diagram thus there was no information about the obstructions present at either end of the runway.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:

The pilot’s failure to maintain an adequate airspeed that resulted in a stall/mush. A contributing factor was the group of trees located near the departure end of the runway.


Re: Sonex Accidents

Posted: Thu Mar 19, 2015 6:35 pm

by rizzz

johnr9q@yahoo.com wrote:…
It would be nice to know why it lost power, did the crank break, etc.

I believe you’ll find that if the exact cause for the “loss of power” has been determined without doubt, the investigation will clearly state that cause.
They generally don’t include speculations or suspicions in the investigations. Only facts that can be traced back to actual findings.


Re: Sonex Accidents

Posted: Thu Mar 19, 2015 8:38 pm

by fastj22

rizzz wrote:

johnr9q@yahoo.com wrote:…
It would be nice to know why it lost power, did the crank break, etc.

I believe you’ll find that if the exact cause for the “loss of power” has been determined without doubt, the investigation will clearly state that cause.
They generally don’t include speculations or suspicions in the investigations. Only facts that can be traced back to actual findings.

True, if its a simple determination, it will be reported. However, if the aircraft is destroyed and the root cause requires a great deal of detective work, I don’t think you will see it. I believe Jeff Schultz’s off airport landing was never determined why his Jab quit. They (FAA) came out, checked his fuel level, turned the prop, then determined engine failure to unknown reasons. To this day, Jeff doesn’t know why his engine quit. They just aren’t very interested in investigating uncertified engine installations. Had this been a C150 with O200, they would have had the engine torn down.

Another thing to consider, since we do our own installs with few established standards we are held to, there are far too many variables to consider.


Re: Sonex Accidents

Posted: Sun Mar 22, 2015 10:54 am

by johnr9q@yahoo.com

Surely some of you people can add information to my list or make corrections. If you come up with something I will make changes to the list and repost. It seems like it shouldn’t be too difficult to find out what engine was in the various airplanes?


Re: Sonex Accidents

Posted: Sun Mar 22, 2015 1:22 pm

by radfordc

You could try cross referencing your list with the Sonex completions site: http://builder.sonexaircraft.com/cgi-bi … ompletions


Re: Sonex Accidents

Posted: Sun Mar 22, 2015 1:23 pm

by radfordc

Also, I think there have been 1 or 2 Sonex fatal accidents overseas. Seem to recall something about one in Italy?


Sonex Accidents

Posted: Tue May 19, 2015 7:57 pm

by Sonex1517

I wanted to post in this topic about something I find very interesting.

In recent months I have been contacted directly by two Sonex pilots with opposite strong opinions.

One insists we are not doing enough to actively post accident data and as a result are not upholding the mission of the foundation. He voiced a very strong opinion in the subject.

Another separate contact was from someone who literally demanded we remove all of the accident data due to how the community is seen from the outside when we post accident data. His demand (and it was a demand) was also very strong.

So as a point of conversation, what does the community think?

I know what I think.

I know what the Sonex Builders and Pilots Foundation has stated its mission is.

What do all of you think?

Robbie Culver
Sonex 1517
Chicagoland
Tails and Wings complete - finishing fuselage.
N1517S reserved


Re: Sonex Accidents

Posted: Tue May 19, 2015 8:12 pm

by Bryan Cotton

Here is my opinion-I think we are good where we are. We have certainly had some accident discussion. In fact, a google search led me to Sonexbuilders when I was looking for accident data. This uncovered the thread on the Waiex that lost its tail. I appreciate frank and thoughtful discussions on accidents. I have lost friends in airplane accidents and I try to learn everything about what went wrong. Hopefully our loss of our fellow pilots can spare us from the same end. But, there is more to the Sonex community than just accidents. There is building, flying, events and fellowship. As far as removing all discussion of accidents, I respectfully disagree with that approach.


Re: Sonex Accidents

Posted: Tue May 19, 2015 8:28 pm

by rizzz

I strongly believe we should be able to discuss everything.
In fact, I would go even further than that and say we should also be able to speculate on possible causes etc. This is something that is often “frowned upon” to say the least.
BUT, much like you stated in the other topic, Robbie:

…those that read the post should be reminded that the post is just that. A post on the Internet in a discussion forum.
.
I strongly believe “people” have to be able to gather as much information and as many different opinions as possible so they can make up their own mind, but off course this assumes “people” have a brain of their own and are willing to use it, not everyone does :).
You need to be able to read a topic within its context and realise that there is a person/company behind this post with feelings, emotions and motives influencing what they’re posting.

Re: Sonex Accidents

Posted: Tue May 19, 2015 9:17 pm

by mike.smith

As for accident data, I see no reason to remove it. Accidents are an unfortunate but very real part of travel, whether by air or otherwise. We try to learn from it. The transportation industries have only gotten safer through (FACTUAL) investigation and discussion. To remove all accident data and discussion is to bury our heads in the sand and not learn a darn thing.

Speculation, on the other hand, is counterproductive as it’s usually wrong, and nearly always biased. Speculation is not discussion. We harangue the media for speculating publicly, then we do it ourselves. To what end? If we really want to give the public the wrong impression, speculation will do it. Personally I won’t get into “discussions” that are not based on the facts as they are known at the time.

Just my 2 cents.


Re: Sonex Accidents

Posted: Tue May 19, 2015 9:52 pm

by kmacht

I agree that we should keep it. It should be it’s own section outside the general discussion forum but it should stay. The foundation is supposed to be supporting safety of the fleet not being a promotional piece for the company. I don’t expect Sonex Aircraft to post accidents on their Web page but I do expect an owners group to actively discuss accidents and accident prevention. There is a certain RV site that if you went to it you wouldn’t even know that there was a near fatal mid air between the rv aerobatics team or any discussion of why it happened yet they promote discussions on formation flying with no problem at all. The only censorship I would expect from this site is if a discussion got personal and out of hand or if the accident pilot specifically asks for a discussion to stop. For me, if I ever dent up my Sonex feel free to openly and actively discuss and speculate. Even if the speculation is found to be wrong later it at least gets people thinking about the possible risks.

Keith
#554


Re: Sonex Accidents

Posted: Tue May 19, 2015 9:57 pm

by ScottM-Sonex1629

Robbie,

I agree we should keep it on the foundation web-site. Links to the site from this forum are enough, probably no need for double posting as that can lead to mistake when transcribing (factual) data.

I know the board of directors are discussing ways to step up this data search and reporting (to keep it up to date) and if any of the forum members have ideas for ways to better retrieve the data and post/upload to the foundation web-site please share your thoughts.


Re: Sonex Accidents

Posted: Tue May 19, 2015 11:08 pm

by Sonex1462

I also agree with keeping the information on the foundation web site. In my 50 years of flying I have always wanted to learn as much as I can to be a safer pilot. We can always learn from both the good and the bad.
Thank You to everyone on the foundation that works to provide us the info we need to be safer Sonex pilots!


Re: Sonex Accidents

Posted: Wed May 20, 2015 9:05 am

by DCASonex

Keep the forum open to discussion of all Sonex related issues. Censorship will discredit both this forum and Sonex. The issues will find an outlet, and people will be getting their information from less balanced sources. Love my Sonex, and think it is one of the best designed out there, but also see room for improvement. Continues improvement is vital to survival in today’s world.

Speculation is inevitable, posted or not. Better to get the wild ideas out there and debunked than suppressed.

Have made some unapproved modifications to mine so that can reach and operate all controls and shut off fuel with shoulder belts tight in event of crash landing. One of those is hydraulic disk brakes that at the time were warned against by Sonex. That warning was sound if the brakes were over powerful or prone to grabbing, fortunately used that warning when selecting mine and they have proved ideal.

David A. Sonex TD with CAMit 3300.


Re: Sonex Accidents

Posted: Wed May 20, 2015 9:14 am

by avee8r

I agree, keep the accident data.
The discussion will always naturally follow on anyway.
Happy Landings
John
N50NX


Re: Sonex Accidents

Posted: Wed May 20, 2015 10:21 am

by sonex1374

Robbie,

Sharing of accident information is essential, and here’s why I say that. I think we all have the desire to learn from other people’s experiences, both good and bad. When the Sonex fleet experiences a loss I think the rest want to know what happened, and most importantly what they can do to either prevent that from reoccurring, or to at least mitigate the risk. We need thoughtful, well thought out presentation of the relevant facts in order to piece together a narrative that answers two basic questions: “Why did this happen?” and “What can I do about it?”.

The issue comes when the discussion turns unhealthy, speculative, and accusatory. Unsupported statements, premature conclusions, or outright name calling are all inflammatory and tend to get people’s blood boiling. When that happens, the discussion becomes more of a liability to all of us than a help. It simply makes us all look bad.

We need to use the Foundation as a place that promotes thoughtful discussion, and airs legitimate issues, problems and negative trends. We need to be patient when the facts are not yet known, and police ourselves against unhealthy speculation. We need to be honest with ourselves and the community, and continually build our credibility. And above all, we need to learn from our mistakes and those of others, and strive to answer the question about what can we a the Sonex community do to prevent these things from happening again.


Re: Sonex Accidents

Posted: Wed May 20, 2015 10:45 am

by chris

Sonex1517 wrote:Another separate contact was from someone who literally demanded we remove all of the accident data due to how the community is seen from the outside when we post accident data. His demand (and it was a demand) was also very strong.

The removal of all accident data will never happen. Respectful accident discussion with the goal of prevention is perfectly acceptable here. It’s a goal of SonexBuilders.net to promote safety. It’s safe to say that SonexBuilders.net and the Foundation share in that goal.

If a Sonex aircraft crashes and we don’t discuss the reasons why, especially after we know why (NTSB report) then how are we to increase safety? I would argue that you are promoting more accidents by avoiding discussion. You cannot turn a blind eye to accidents or put your earmuffs on and help to lower accident rates. It just doesn’t work that way.

If we were to delete all things bad that happened, we would be denying everyone who flies a Sonex aircraft information that could help to prevent that same something bad from happening to them too.

That’s the official view about accident discussion from SonexBuilders.net.


Re: Sonex Accidents

Posted: Wed May 20, 2015 10:55 am

by Rynoth

The accident discussion about the Waiex tail separation was very valuable to me as a builder. As someone new to this, it made a strong impression to me on the importance of such things as proper deburring and using appropriate hardware. Now, I believe it remains unresolved whether either of those things contributed to the accident, but the DISCUSSION about the accident provided me with valuable (and relatable) insight for my build.


Re: Sonex Accidents

Posted: Wed May 20, 2015 6:40 pm

by rizzz

Rynoth wrote:The accident discussion about the Waiex tail separation was very valuable to me as a builder. As someone new to this, it made a strong impression to me on the importance of such things as proper deburring and using appropriate hardware. Now, I believe it remains unresolved whether either of those things contributed to the accident, but the DISCUSSION about the accident provided me with valuable (and relatable) insight for my build.

And that is where open “speculation” (or whatever you want to call it) is actually beneficial, hence I don’t believe we should suppress/censor it.
I agree though that allowing this can easily turn a healthy discussion into a toxic one and we should be mindful of this.
Luckily most people who have been around this forum (and its predecessor) long enough know how to filter the information, but I can see how Sonex LLC would be more worried about the occasional lurkers and first timers who might be potential customers focusing on the odd negative unproductive posts and turning them away from a great aircraft.
I would like to think though people who decide to buy/build and aircraft, which is a major life changing decision, do their research a bit more thoroughly.

Anyway, the question then arises:
Is the primary goal of this forum to be a place where (potential) Sonex builders and pilots can get advise, discuss great or not so great experiences, issues, concerns, safety, etc?
Or,
Is it more to promote Sonex LLC and the Sonex line of aircraft?

As the discussion in this thread suggests, the two options above do not always align.

I’m happy to see Chris’s (official) viewpoint on this matter at least from a safety perspective.

Sonex Accidents

https://sonexbuilders.net/viewtopic.php?f=25&t=1852

Page 3 of 4

Sonex Accidents

Posted: Wed May 20, 2015 7:51 pm

by Sonex1517

Great discussion.

I am going to add to Chris’s statement and state we have zero intention of removing the accident data from sonexfoundation.com - in fact, we hope to continue adding to the dataset to improve the knowledge base and hopefully raise awareness of the root cause of the issues. Sadly, the root cause is often us.

To their credit, Sonex Aircraft LLC has never raised the publication of this as an issue. One vocal former foundation member did. One. I am hoping this person reads this thread.

There is always a fine line between supporting the Sonex factory and open honest conversations. It is in all of our interests to do both, but to do so responsibly. I think that is the hardest part of it all.

Robbie Culver
Sonex 1517
Chicagoland
Tails and Wings complete - finishing fuselage.
N1517S reserved


Re: Sonex Accidents

Posted: Thu May 21, 2015 11:56 am

by SvingenB

Is the primary goal of this forum to be a place where (potential) Sonex builders and pilots can get advise, discuss great or not so great experiences, issues, concerns, safety, etc?
Or,
Is it more to promote Sonex LLC and the Sonex line of aircraft?

To be honest it is more of the latter than the first, something this very discussion proofs. It’s the main reason I don’t trust anything here other than the obvious straight answers about pragmatic stuff. There is only one kind of discussion, the healthy one where people are honest and disagree. If it’s not, it’s not a discussion, and not useful for anything.

It would be nice if the moderators had more integrity.


Re: Sonex Accidents

Posted: Thu May 21, 2015 12:22 pm

by chris

SvingenB wrote:It would be nice if the moderators had more integrity.

I would like to remind you to read the posting guidelines.

That is confrontational, not respectful, and a personal attack on the moderators.


Re: Sonex Accidents

Posted: Thu May 21, 2015 12:36 pm

by SonexN76ET

To me the moderators have shown a very high level of integrity and sound judgement. For example when a poster makes a claim that something sold was “junk” simply because that item did not include a materials traceability document showing the manufacturer of the part the moderators let it continued. If it were up to ME I would have made the poster edit the post and required that the statement say what the part was, why you were dissatisfied with the part and give a positive recommendation on what Sonex could do to improve the part. Just saying something is junk is throwing mud. Another example is the endless postings on fuel tank fittings. A couple of people have over torqued their fittings or not protected the lines from vibration or loads and developed leaks. Reading their posts you would think all tanks were leaking. I know many long time owners of Sonex aircraft who have never had a leak. The moderators let this thread and others like it continue.

My bottom line with this post is that the moderators are more than fair and have a high level of integrity. This forum should be positive. Even when we don’t like something we should state exactly what we don’t like and offer positive suggestions for improvement.

As far as accidents go, with experimental aircraft (because of build differences) you need to look for accident trends and identify problem areas so those problems can be addressed. Learning from others is a sure way to ensure you don’t suffer the same fate.

Enjoy building and flying your Sonex! I sure am!

Jake


Re: Sonex Accidents

Posted: Thu May 21, 2015 3:29 pm

by vwglenn

SvingenB wrote:

Or,
Is it more to promote Sonex LLC and the Sonex line of aircraft?

To be honest it is more of the latter than the first…

This may seem true but everyone who owns, builds, or operates one of these aircraft has a vested interest in promoting the Sonex line of aircraft so I don’t think it’s a corporate conspiracy. It’s simply human nature. We all want to have the most awesome plane ever designed so healthy positive discussion comes naturally but criticism is met with more resistance. You certainly need to be more careful on a message board when you want to post potentially negative things because neither the community or the mods will take it for long. Everyone here needs to remember these planes are like children to the owners/builders and you can’t insult another persons child (true or not) and expect them to just stand there and take it. Negative opinions and speculation will get you nowhere fast.

It’s a sad fact but forums always have to have moderators or they don’t last long. The goal is to protect the forum from devolving into a complete mud throwing contest which can happen extremely fast when people are able to hide behind a keyboard and have no accountability for their actions. Mods keep that from getting out of control. The problem is a violation of posting rules can be subjective. There’s no way around this so all posters need to have some thick skin sometimes.

Plus there is also the problem with written communication. The omission of punctuation can completely change how a line of text is understood. Sarcasm is completely lost. Nonverbal cues are not present. This can also lead to completely different interpretations of the same text.

Because of all these things, accidents need to be discussed with tact and only the facts. It’s a good discussion to have because we can certainly learn from it and simply having a reasonable discussion could easily save a life or multiple lives.


Re: Sonex Accidents

Posted: Fri May 22, 2015 10:09 pm

by SvingenB

If it were up to ME I would have made the poster edit the post and required that the statement say what the part was, why you were dissatisfied with the part and give a positive recommendation on what Sonex could do to improve the part.

And why do you assume I haven’t already been in contact with Sonex about these things long before? I have since long moved on and got new parts from other sources, as I am sure most do. Just because I have different standards about specific things compared with what Sonex apparently have, does not mean one is right and the other is wrong. Still, it is my aircraft, and I want to trust every part on it.

everyone who owns, builds, or operates one of these aircraft has a vested interest in promoting the Sonex line of aircraft

That makes no sense unless you for some reason are uncertain of your “investment”, but it’s probably true nonetheless. But that is no reason to prevent honest discussions. Quite the opposite in fact. We all want to get the most out of our investments, no matter if we perceive them as good or bad or simply are uncertain. The end product will talk for itself (good or bad) no matter what is said on this board. The thing is, if we all were honest, the end product would only end up better. You have to take possession of your investment. You have to be in charge of your investment, not the other way around. That is the only way to protect your investment. We are the ones spending money on this, not Sonex.

Besides, people do communicate also outside this board.

Just for the record. I have no problems recommending the Onex to everybody. Well, everybody who wants a single seater kit. I have no problems recommending the Aerovee either, but with certain strings attached.


Re: Sonex Accidents

Posted: Fri Jun 12, 2015 10:39 am

by johnr9q@yahoo.com

Sonex Accident Report Update


Re: Sonex Accidents

Posted: Fri Jun 12, 2015 10:46 am

by johnr9q@yahoo.com

ScottM-Sonex1629 wrote:Robbie,

I agree we should keep it on the foundation web-site. Links to the site from this forum are enough, probably no need for double posting as that can lead to mistake when transcribing (factual) data.

I know the board of directors are discussing ways to step up this data search and reporting (to keep it up to date) and if any of the forum members have ideas for ways to better retrieve the data and post/upload to the foundation web-site please share your thoughts.

If you reread my original post. I started this post because the information on the foundation web site was not up to date or complete. Maybe that will change, if so the information I am providing will be unnecessary


Re: Sonex Accidents

Posted: Fri Jun 12, 2015 10:50 am

by Sonex Foundation

We have been working to update the page. Dana Baker has done an excellent job of finding the correct links for those accidents we are able to find in the database.

http://sonexfoundation.com/Accident_Information.html


Re: Sonex Accidents

Posted: Thu Mar 01, 2018 8:59 pm

by johnr9q@yahoo.com

I am the original poster and I see no improvements in the accident information provided in the Sonex Builders and Pilots foundation. If you look at the following you will see there have been a bunch of accidents not reported. https://aviation-safety.net/wikibase/db … cType=SONX

Re: Sonex Accidents

Posted: Thu Mar 01, 2018 9:44 pm

by Sonex1517

johnr9q@yahoo.com wrote:I am the original poster and I see no improvements in the accident information provided in the Sonex Builders and Pilots foundation. If you look at the following you will see there have been a bunch of accidents not reported. https://aviation-safety.net/wikibase/db … cType=SONX

That would be correct.

If you feel like you have time and energy to be involved, please step up and help the foundation. It is an all volunteer effort in need of assistance.


Re: Sonex Accidents

Posted: Fri Mar 02, 2018 12:09 pm

by johnr9q@yahoo.com

That would be correct.

If you feel like you have time and energy to be involved, please step up and help the foundation. It is an all volunteer effort in need of assistance.

I am a Sonex lurker. I would love to build one but probably never will. I spend all the money in the family for Mountain Biking and Rock Climbing and trips for same and my wife asks permission to buy a new knitting needle so I feel guilty taking on another hobby. It just seems to me that to have a database that would include all accidents and be a lot more comprehensive than the one I quoted in my earlier post
https://aviation-safety.net/wikibase/db … mit=Submit or the one I compiled in my initial post file:///C:/Users/John/Downloads/Sonex%20Accidents%20(9).pdf would be something that SonexBuilders would work hard to insure was compiled. I developed my initial list because I was concerned that putting a turbo on a VW engine was expecting too much for that little engine to handle. I see that many others also are concerned about this. When Sonex CEO Jeremy Monnett was killed when that engine failed I thought there would be more discussion on the subject so I did my own research to find out the reliability of that engine but couldn’t find much. Maybe I’ll try to get my list up to date but I won’t expect much help from this forum. I asked for people to give me inputs but there has not been a response on this thread since 2015. If people want, they can email me at johnr9q@yahoo.com and help me out with information I can add to the list. Mainly looking for what type of engine the aircraft had and cause of the accident. I realize there isn’t complete investigations of many Sonex accidents but probably word of mouth etc will provide some insights into cause.


Re: Sonex Accidents

Posted: Fri Mar 02, 2018 2:57 pm

by chris

I started compiling some research a year or so ago in a google spreadsheet about sonex stall spin accidents with data from the NTSB . I included links to the NTSB site as well as probable cause and some other items. I did not include the type of engine on the aircraft as that was not my interest at the time. I only made it as far as 2011.

But I would like to offer a solution. We can combine the data from Johns pdf with my data, add a powerplant column and then finish it out for the past 7 years. I would like to share this Google Sheet via PM so that anybody who wants to help me can collaborate. SO if you want to help compile this data then PM me your email address and we can work together. Preferably applicants will be familiar with working collaboratively using google sheets.

Edit : Up to mid 2014 now on the spreadsheet and removed a comment that John might have found offensive.


Re: Sonex Accidents

Posted: Fri Mar 02, 2018 9:34 pm

by lutorm

What we need for things to be really useful is not just information about accidents but also information about the not-accidents. We need to know what engines people have that haven’t had a failure, we need to know how many hours people fly without having an accident, etc. Without this info you can’t draw any conclusions.

For example, if we get a list of engine failures that have 10 Aerovees and 0 Corvairs, it doesn’t tell us anything. Maybe there are 0 Corvair failures because there just aren’t enough of them flying. Or maybe the Corvair is really significantly more reliable. Impossible to tell.


Re: Sonex Accidents

Posted: Fri Mar 02, 2018 10:37 pm

by chris

This data is basically just the NTSB data from Sonex Accidents in one location.

This is an incomplete work in progress but viewable here:

http://sonexbuilders.net/accidentdatabase/

I would like to point out that despite of all the complaints, I have yet to receive any offers of assistance regarding the database.

If anyone would like to add additional data or help with future updates, please PM me.


Re: Sonex Accidents

Posted: Sat Mar 03, 2018 2:00 pm

by daleandee

lutorm wrote:For example, if we get a list of engine failures that have 10 Aerovees and 0 Corvairs, it doesn’t tell us anything. Maybe there are 0 Corvair failures because there just aren’t enough of them flying. Or maybe the Corvair is really significantly more reliable. Impossible to tell.

Concerning Corvairs in particular I’m only aware of perhaps two to three dozen (I haven’t kept up with it) of the Cleanex type aircraft having flown. I’m not aware of any failures in these few that can be attributed to the engine itself.

Keep in mind that there are variations in builds as there are with the VW engines (Aerovee, Hummel, Revmaster, Etc). So how would the specifics break out? As an example would the list have VW engines (every build type listed) or Aerovee only. Would it have all Corvairs (WW i.e. Fly Corvair, Dan Weseman i.e. SPA, Bill Clapp i.e. Azalea,) or only the William Wynne conversions? Would we look at only Viking engines (Eggenfellener) or any Honda type conversion (Raven, Firewall Forward Aero)?

To my knowledge, in Cleanex type airplanes the only recent Corvair incident that comes to mind is this one:

https://app.ntsb.gov/pdfgenerator/ReportGeneratorFile.ashx?EventID=20170422X03928&AKey=1&RType=HTML&IType=LA

Seems the reason for this failure is pretty clear.

No doubt that other Corvair powered airplanes have had accident/incidents. There was a Corvair powered Zenith crash near me a couple of years ago when it ran out of fuel returning from a cross country. Many are aware of the crank breaks that Mark Langford had in his KR. So, as they say, no engine is perfect. I only trust mine completely when it’s in the hangar and not running.

BTW … if there are secrets to getting this information to come up on the NTSB site I’d like to know them. As noted earlier, this information can be very difficult to track down and the REASON for failures is most times still unknown. But that’s exactly what we need in order to minimize the accident rate.

Hope this helps …

Dale Williams
N319WF @ 6J2
Myunn - “daughter of Cleanex”
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
Signature Finish 2200 Paint Job
171.9 hours / Status - Flying
Member # 109 - Florida Sonex Association
Latest video: https://www.youtube.com/watch?v=1VP7UYEqQ-g