Re: Whats the true safety record for Rutan Designs?


aviationeyes
 

Wow. Sounds like a great story to discuss on Friday virtual shop nights. 

On Fri, Jul 23, 2021, at 8:06 PM, Charles McDougal wrote:
Here’s something in the “my two cents” category; totally anecdotal. 

I had two engine failures in my EZ, both at night, both resulting in an off airport landing. One was a piston pin plug failure, eventually causing oil starvation. The other was a new Superior Air Parts crankshaft snapping like a twig in an all new professionally built engine with less than 400 hours TT. In both events, the airplane stayed upright. In the second, my wife was with me. (Yes, we are still married). We got a little banged up but no injuries requiring treatment. 
Cmcd



On Jul 13, 2021, at 11:03 AM, KEN4ZZ via groups.io <ken4zz@...> wrote:


Hi Izzy-

Just FYI - I wouldn't get to worked up re using that data.  I'm line 28.  It WAS a roll over - not listed as such.  Listed as 'substantial damage'.   I guess that's subjective, but I had N4ZZ repaired and flying the next spring.  I calls my plane a LongEZ.  Nope; it's a VariEze.  Point is, while I have no doubt that your analysis methodology is sound, the source data was perhaps, ummmmmm, many times recorded in a less than precise manner.

I've been told by several folks that non-commercial light aircraft accidents that are non-fatal do not get high priority from the NTSB.  True???  I can't say one way or another.

Ken

On 7/13/2021 11:00 AM, I. N. Briggs via groups.io wrote:
Correction, 
"there are 27 accident Event ID's that report the aircraft ended up inverted, suggesting an 8.5% probability the aircraft will come to rest inverted. "

Should read
"there are 27 accident Event ID's that report the aircraft ended up inverted, suggesting an 12% probability the aircraft will come to rest inverted. "

Izzy
(603)410-7277


On Tuesday, July 13, 2021, 11:53:19 AM EDT, I. N. Briggs via groups.io <inbriggs@...> wrote:


Attached is an analysis I performed on the NTSB Database in 2011. The reason I did this was to try to determine how often a canard could roll over during an accident with an eye towards justifying the effort, weight and complexity of designing reliable and functional rollover protection in my Cozy IV. This analysis result is reflected in the "Rollover?" field for each record. 

The list includes a record of every NTSB reported Rutan based canard accident the NTSB investigated which I was able to identify from 1983 until 2011. The list selection criteria was Rutan or Rutan based designs only. Because the builder could name the design anything they wanted to, it's possible there are Rutan based canards not included in this list, particularly if they had an unconventional Make or Model name. If the NTSB didn't report on it, it wasn't in the list, so it's likely there are many that never captured the attention of the NTSB.

I identified 229 NTSB accident events meeting the criteria in the date range. No data was published prior to 1983. 

The accident reports were text only and typically no photos of the scene were available so I only reported "Rollover?=yes" where there was some comment or other evidence that the aircraft ended up inverted. In some cases, I searched the archives, CP and Canard Newsletters for additional details for a given accident. 

There are 27 accident Event ID's that report the aircraft ended up inverted, suggesting an 8.5% probability the aircraft will come to rest inverted. Out of those 27 records, 9 Event Id's reported at least one fatality. So if the aircraft does end up inverted on the ground, there's at least a 1 in 3 change someone won't survive it. 

The actual numbers are probably higher since many of the reports didn't explicitly state the final resting orientation of the aircraft and photos were not available unless I paid huge sums of money to the government and requested the "blue file" (or something like that) from the NTSB for a given accident. 

Now, is the fact that it's inverted the reason for the fatality? No, that's not a valid conclusion. But the ratios are significant enough that a reasonable person might decide that the design could be made safer with correctly designed rollover protection. So who's responsibility is it to design such a system? The builder? The Operator? If it's not correctly designed, it could make things worse, as is the case with N795DB. 

Given my personal priorities (1. Safety, 2. Reliability, 3. Performance, 4. Aesthetics), the numbers suggest rollover protection is worth the extra weight,time to build and complexity for some builders and fliers. 

When I went to the community with this, there wasn't much of a splash and a lot of pushback. I attributed the indifference to a lack of ownership for the design (which supports Dick VanGrunsven's comments). Some feel the plans provide adequate protection, but the numbers don't support this. Since no one is responsible for the design anymore, we are left to our own "devices". Sadly, N795DB had an improper rollover protection device installed, a side hinged canopy (on a Cozy 4) and spar mounted battery that departed the mount. The result was a battery that hit the canopy support when it flew off the spar, which twisted the canopy clockwise, then broke the rollover protection that was incorrectly bolted to the top of the pilot seat back. The metal rollover bar impacted the pilot at the base of his skull which resulted fatal blunt force trauma to the back of the pilots head. This was not in the NTSB report. This information came from a direct interview with the widow who shared with me the autopsy report. The accident would likely have been survivable had the builder used something like Mike's design. 

Mike Melvill created some plans (attached) for rollover protection which you can actually see installed in his LongEze in the July 2021 Canard Calendar. 

Tell Tracy I said hello and good luck with her presentation. 

Izzy
(603)410-7277


On Monday, July 12, 2021, 09:49:42 PM EDT, Ryszard Zadow <ryszardzadow@...> wrote:


The reason for the subject of this post comes from the comment Dick VanGrunsven made at the 2019 RAFE forum "The Future of Rutan Designs Symposium". Dick stated the safety record of "orphaned designs:" was not good. Though I believe we have more support out there than most "orphaned designs" like it of not, we technically fit in that definition so I was wondering if anyone has every actually crunched the numbers by searching the NTSB and/or Air Safety Foundation databases? 

We're hosting that forum again this year. The lead in topic will be about insurance and the aging Pilot. Tracy Martin of Aircraft Insurance Resources will be on the stage and hopefully a few other experts like we had in 2019. Tracy will discuss the dilemma many Pilots face now and we all may one day. 

See y'all there July 31, 0830 am , Forum Stage 5 

If you missed that 2019 forum the full recording of it is on YouTube at The Future of Rutan Designs Symposium AirVenture 2019 





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