Accident Database / Post Crash Fires / How many flying?

[GordonTurner]

Hi Graeme

Many of the Corvair powered airplanes go by “Cleanex” or some derivative of that. Can you add that to your search?

Gordon

[GraemeSmith]

Hi Graeme

Many of the Corvair powered airplanes go by “Cleanex” or some derivative of that. Can you add that to your search?

Gordon

No joy. I found the most reliable way of bubbling up aircraft was to use the search term "Sonex" in the "Kit Manufacturer field of the FAA database. Any which way I sliced that got me the maximum number of results.

If you have the N number of a Cleanex - then I can look and see how it is portrayed in the database and see if I already got it - or if it gives me something new to look for.

[daleandee]

Many of the Corvair powered airplanes go by “Cleanex” or some derivative of that. Can you add that to your search?

FWIW ... as a Cleanex owner I try to keep close tabs on Corvair powered aircraft (of any kind) that have incidents or accidents. As it relates to this thread I'm only aware of a single non-fatal accident that seems to have a reasonable explanation as to the cause:

http://www.kathrynsreport.com/2019/02/s ... il-22.html

I discussed this accident in my thread titled "Corvair Engines - The Justification Series" and also referenced two important points that the NTSB report (at that time) noted were the causes of accidents for experimental airplanes. Here is the text from that thread from the NTSB report:

• Accident analyses indicate that power plant failures and loss of control in flight are the most common E-AB aircraft accident occurrences by a large margin and that accident occurrences are similar for both new and used aircraft.

• Structural failures have not been a common occurrence among E-AB aircraft.

The entire thread is found here: viewtopic.php?f=9&t=4273&hilit=justification

Hope this helps ...

[WesRagle]

Hey Dale,

Don't forget this one.

https://sonexbuilders.net/viewtopic.php?f=21&t=5637&p=42654&hilit=clay#p42649

Wes

[GraemeSmith]

So here it is with Engine Types added in. I had to go trawl the FAA Database and NTSB Final Reports to put this together.

The new data is in the cream colored columns and is as worded from the source data - so you have to do a little interpretation. But basically 18 Jabs, a Viking, a Corvair and the rest are VW based. Ignore 2 turbines on the Sub-Sonex.

Now just because an engine appears in a report - does not mean it was the cause. When someone taxis into you and chops the tail off your Sonex - you appear in the report - but the engine has nothing to do with it. Same for a Waiex structural tail failure in flight - poor build quality on what turned out to be a marginal design. Pilot ground loops the take off - nothing to do with the engine - well not directly. Another - an alcohol imparied pilot.

So read in conjunction with the probable cause narrative line.

[GraemeSmith]

So this commentary is from Steve Brown who is the FAA Safety Manager at the Boston FSDO. I am a VOLUNTEER safety rep for the FAA. I can't speak for them or say anything authoritative on behalf of the FAA - but I give talks for WINGS credits sometimes. I was sharing my work with him to try and get some greater context - as he has a "bigger view" of all types of EAB. Steve is a "good guy". On the side of GA. He wants to make things safer too. This comment from him and graph are published with his explicit permission:

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As always, interesting. That is a large percentage of the fleet.

Looking at your spreadsheet there was something that caught my attention. The Rate of Fatal Accidents. I know it and all Experimental aircraft tend to have a higher rate of Fatal Accidents, but just looking at the data it seemed high.

Here is a comparison of a chart from your spreadsheet data and the NALL report data. It appears that about 1 in 3 accidents in a Sonex are fatal, where in all other experimental it is about 1 in 4 or 5.

You know what would probably be scarier – is the rate per # hours flown. Would be hard to get the data, but I bet the hours are low and the rate per 100,000 hours is high. That is something in the glider world that many people have a hard time comprehending. There the Fatal Accident rate is about the same as the overall fixed wing accident rate, with the overall glider accident rate being about 4 times high. I bet you would see at least the same in the Sonex world.

I looked quickly at the trends with the engine type on accident severity, but nothing was really jumping out at me.

Boy – there are a lot of engine issues, loss of power, especially in the Fatal and Serious Accidents. A top Priority on pilot skills would be “dead Stick” landings. The structure is not that massive/energy absorbing, if you are going to hit something, you need to do it as slow as possible and in control as much as possible. You need to be prepared for engine failure.

Now, that being said, more of a root cause is the engine assembly/maintenance of the engine and components. There are a lot of failures for reasons that should not be there. That is where I would put the focus to reduce the accident rate overall. Reduce the Fatal and Serious accident by strong emphasis on engine out procedures, off airport landings and as Bob Hoover said, “Fly it as far into the crash as you can”.

Thanx
SKB

[BRS]

Thanks Graeme,
Steve's admonition of engine-out and dead-stick proficiency is well taken. Once again the need for training is underscored and the lack of availability is highlighted.

[radfordc]

If deadstick, off-airport landing skills are needed (and it is evident they are) what is the best way to acquire those skills? Is the typical Flight Review procedure enough (CFI says "you have an engine failure" and pulls throttle to idle, student looks for a landing field and sets up an approach. On final the power goes back in and climb out ensues). What's missing here is the "startle factor" that comes from knowing the engine just quit for real; the problem of multi-tasking: trying to get the engine restarted, looking for a landing spot, making emergency radio calls, and last (but not least) flying the plane. I do know from my own experience that experiencing an actual engine failure is mentally much different than just doing a practice approach at idle power.

[pfhoeycfi]

There are great articles in AOPA, EAA, Flying and from the FAA on how to best perform the power off 180 deg approach and landing and its actually a good exercise to do on towing days where I'm making 15... 20 ...30 landings.

[GraemeSmith]

If deadstick, off-airport landing skills are needed (and it is evident they are) what is the best way to acquire those skills? Is the typical Flight Review procedure enough (CFI says "you have an engine failure" and pulls throttle to idle, student looks for a landing field and sets up an approach. On final the power goes back in and climb out ensues). What's missing here is the "startle factor" that comes from knowing the engine just quit for real; the problem of multi-tasking: trying to get the engine restarted, looking for a landing spot, making emergency radio calls, and last (but not least) flying the plane. I do know from my own experience that experiencing an actual engine failure is mentally much different than just doing a practice approach at idle power.

I put my survival from a real engine out (non Sonex) over mountains and over the top VFR down to practice, practice, practice. You revert to training in crisis. You are terrible at making it up on the spur of the moment. So when the engine quit - I was - Establish Vg, NRST - DIRECT - MAYDAY call and settled down to try and pull off a 12 mile glide to a runway with just altitude for 10 miles in the glide tank. I made it with 1,000ft to spare and had to slip her in hard. Because I trained for it.

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I practice all my airwork and drills REGULARLY. Just these last three flights I've been doing long glide engine outs. First two - WAY too high, had to spiral off altitude on final and STILL was way too high if I'd been landing it for real. Took till today to nail it and have energy to roll in and get off the runway.

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Big letters on the panel - "Minimum Maneuvering Speed - 60 KIAS at 45 degrees". Practice, practice, practice don't break it and you should avoid "stall spin".