Sonex down at Osh. Two dead..R.I.P.

[1600vw]

http://www.thenorthwestern.com/story/news/local/2015/06/02/plane-crash-oshkosh/28370861/

[1600vw]

Jeremy Monnett was one. R.I.P. Very sad day.

[1600vw]

http://www.aero-news.net/index.cfm?do=main.textpost&id=0481840a-33a8-40be-a007-810658c8b4e0

[CarlOrton]

I'm...just...devastated...by this news. How awful. Jeremy was a friend who was always thrilled to see you. Nothing I type can begin to address how I feel.

[1600vw]

I'm...just...devastated...by this news. How awful. Jeremy was a friend who was always thrilled to see you. Nothing I type can begin to address how I feel.

I agree. So very sad.

Tony

[krw920]

What a great loss for the Oshkosh area and the aviation community as a whole. You will be greatly missed Jeremy. God Speed.

[JustPlaneChris]

Sad and shocking. :(

I just have a sick feeling upon reading this news. My sincerest condolences to John and the rest of the family.

Chris (builder and former owner of Sonex #260)

[1600vw]

http://sonexaircraft.com/

[1600vw]

I would like to hear the cause of this as I am sure many would. If this can happen to these men this can happen to anyone. Be safe out there enjoying our Hobby/Sport. I may not know any of you but it still hurts when this happens.

Tony

[glider90]

What a sad day for the EAA family. I am sure in due time initial findings and a full report will come out, however I am left wondering how much of a contributor the proximity of the Oshkosh military vehicles played in this. I have attended OSH only as a spectator not a pilot so it is hard to judge how close the vehicles actually are. This incident and the one with the Breezy at the convention last year may have had better outcomes if the vehicles where not there.

[1600vw]

The government owns enough land, why not keep things like this at those places. Myself I am tired of seeing all the military vehicles all around. Just me but they should not be on any public or private anything. I do not need to see how much might our government has, I know this.

Lets stop this now. If those trucks had not been there I really doubt we would even be having this conversation today.

Tony Sweet

[gbrasch]

I flew into OSH last year and in no way can I see how those trucks could have contributed to this accident, lets not add politics to this tragic event please.

[1600vw]

I flew into OSH last year and in no way can I see how those trucks could have contributed to this accident, lets not add politics to this tragic event please.

Really, the airplane is setting on top of those military vehicles but they had nothing to do with it. While its true these military vehicles did not cause the airplane to come out of the sky, they did have a part in the fact the airplane is setting on top of them.

If those trucks where not there would we be talking about this. They had a lot to do with this.

Tony sweet

[rwanttaja]

Really, the airplane is setting on top of those military vehicles but they had nothing to do with it. While its true these military vehicles did not cause the airplane to come out of the sky, they did have a part in the fact the airplane is setting on top of them. If those trucks where not there would we be talking about this. They had a lot to do with this. So, you're saying that if the trucks hadn't been there, the plane would have missed the ground completely? Or that the impact would have been survivable? Please show your basis for this assumption...knowledge of the impact angle, speed at impact, etc. Why would hitting an unarmored military truck be less survivable than a civilian Kenworth, Hummer, or Dodge pickup? Finally, I have to say this: Attempting to make political hay off this tragedy is reprehensible. Ron Wanttaja

[glider90]

I originally questioned the trucks location, not because they are military but because they appear close to the sides of the runway if you have an off runway excursion on landing. This was a factor in the Breezy incident for certain according to the NTSB report:

"The amateur-built ****** Breezy touched down on Runway 36R and "appeared to bounce during the landing roll," the NTSB report states. The Breezy then veered right off the runway and struck armored vehicles parked near the airport perimeter."

I simply raised the question as it seems there was contact with them again after a landing attempt. I did not intend any political statement, I merely wanted to understand how close they are. I should have known better than to ponder out loud on a web forum I guess. Emotions are high after a horrible event. I google mapped the location and I now have a complete understanding of the location of the vehicles with respect to 36R and runway 9, so my questions are answered.

I hope we can return to simply mourning the event and wishing our best for the families and friends of those involved. Sorry for the tangent.

[1600vw]

So, you're saying that if the trucks hadn't been there, the plane would have missed the ground completely? Or that the impact would have been survivable? Please show your basis for this assumption...knowledge of the impact angle, speed at impact, etc. Why would hitting an unarmored military truck be less survivable than a civilian Kenworth, Hummer, or Dodge pickup? Finally, I have to say this: Attempting to make political hay off this tragedy is reprehensible. Ron Wanttaja

So you are saying if nothing was there this still would have happened in the way it did. I had an engine out, a few in fact and not one resulted or had the outcome this did.

I am saying if nothing was in that spot more then likely we would not be talking about this. It just seems that a bad place to store things like this is at an airport. Not an airport that has a lot of experimental airplanes flying in and out all the time. Why not keep government military vehicles on government land?

My question, why do we store these things in spots like this? I believe airplanes land on the ground everyday and this does not happen. But your response sounds like any power off landing, they are doomed to crash into the ground. It looks as if they landed pretty flat to me. How about those two airplanes in Alaska that landed on each other at 100' All walked. But if they would have landed on parked trucks I am sure the outcome would have been different. This is all I am saying.

From what you are saying you believe they slammed this airplane into the ground and it matters not if the ground was clear or had obstacles in the way. The outcome would have been the same. I just do not see it that way.

But like you pointed out, who am I.

Tony

[1600vw]

It does no good to just morn what happened. We or I want and need to learn from this. Why you ask. Because if this can happen to these two men, this can happen to anyone/me.

You view this as an argument. I view this as a discussion about safety. You call it what you want. I have already said in many other post how sorry I am this happened and how it saddens me.

Tony Sweet

[1600vw]

Ron if that airplane would have come down hard would it not have been in worse condition then it was? I am amazed there was not a fire. Because I see no fire, I can only determine that this was not a really hard impact with the ground. That and the airplane looks to be in one piece. If it had slammed the ground would it not be in worse condition.

I ask this not arguing but trying to understand this. The most frightening thing to me is an engine out on climbout. I have had a couple. I have also had a couple in flight with one being the loss of the reduction unit and prop. Not one ended as this one. One did come close though.

I had been soloing for a few hrs. On Climbout I loose the engine. It just stopped. I did as trained and landed straight ahead. Problem was my flight ended in the middle of a ditch about 30' wide and 20' deep. I saw this ditch coming and kept her about 10' high. I stalled right in the middle of the ditch about 10 above it. Doing this caused on the stall and drop I went forward some. I slam the opposite bank of the ditch with the mains right at the top. The mains missed going onto flat land by about 6 inches. I slam the bank. The airplane goes up on its nose and stayed in this position what seemed like two or three mins. I am pushed against the belts thinking go over already. She came back down on the wheels and I crawl out. Now I am on flat land. All wheels landed on flat ground once the airplane came back down on its wheels. I did not get hurt nor did the airplane, it was a pusher. We pulled it out of the field with an atv. My instructor saw all this happen and said. You should have turned. I told him all I could hear was his voice telling me to fly straight, land straight ahead. he said I did just fine.

But if I had landed on something that day I am not sure I would have walked away.

I mean no disrespect to anyone and I am grieving what happened here just as everyone . I have to make heads and tails of this. I do respect what you do Ron. I hope you understand this. I am not arguing, just trying to understand how these very talented men came to this. I know they say 90% or something like that is pilot error. But I don't see it here. But again what do I know.

R.I.P.

Tony

[rwanttaja]

It does no good to just morn what happened. We or I want and need to learn from this. Why you ask. Because if this can happen to these two men, this can happen to anyone/me.

You view this as an argument. I view this as a discussion about safety. You call it what you want. I have already said in many other post how sorry I am this happened and how it saddens me.

But, of course, in an earlier post you blamed the US Government for the vehicles sitting where they were. "The government owns enough land, why not keep things like this at those places. " In all likelihood, the vehicles were still owned by the manufacturer (e.g., pre-delivery). Don't know why you brought the Government into it. Whether the trucks contributed to the severity of the accident or not, the fact that they were being sold to the Government is immaterial.

We'd all like it if every airport had a five-mile radius that was nothing but green meadows and pillow corrals. But the reality most of us face is different. I took at photo at my home drome about twenty years ago; a Cardinal has lost power on takeoff and pancaked into the dirt a quarter-mile from the runway. That spot is now a day care, with a strip mall and a Lowes' around it.

Obstructed forced-landing locations are a fact of life. I don't like it that a Dairy Queen sits just short of the approach end of my home field...nor that a set of bazzilion-volt power lines crosses a short distance off OTHER end of the runway. But if the engine quits, that's the hand I'm dealt and I hope I play it as well as possible.

I am intensely uninterested in pre-analyzing this accident...I completed some accident analysis for Mr. Monnet just two weeks ago. But I find the wreckage's final location and condition (upright, flat *atop* a truck with the tail section apparently mostly intact) of interest.

Ron Wanttaja

[rwanttaja]

Ron if that airplane would have come down hard would it not have been in worse condition then it was? I am amazed there was not a fire. Because I see no fire, I can only determine that this was not a really hard impact with the ground. That and the airplane looks to be in one piece. If it had slammed the ground would it not be in worse condition.

We had a set of posts cross. As I mentioned there, I'm not really interested in pre-analyzing this early, but: The amount of damage to an aircraft (and its occupants) is exponentially related to the speed at which it hits. The amount of energy involved is related to the square of the speed...hit twice as fast, the airplane and occupants suffer four times as much.

Conversely, all things being equal, the less damage the airplane exhibits, the slower it was going. A lot of things affect this...a glancing first impact to slow the plane down, the nature of what it hits, etc. You can be killed on a bicycle; Frank Tallman had to have a leg amputated from tripping off a curb.

In all probability, the plane was travelling slowly when it hit. They may have had bad luck with the first thing they hit...but I think, typically, you see more tail cone damage in these cases as the plane tumbles. But, of course, the OTHER way it could hit slowly is vertically...deep stall or incipient spin.

We had a Fly Baby accident last year after an engine failure. It went down in a grove of trees. The NTSB report comments that the trees were damaged in a hole only slightly larger than the aircraft...in other words, it went straight in, probably stalled. In the pictures in the docket, the Fly Baby's fuselage is broken off just behind the cockpit and is remarkably intact. So are the wings, for that matter...but the forward fuselage is shattered. No fire, despite a fuel tank located above the pilot's legs right behind the engine.

So the NTSB investigators will be examining the debris trail, attempting to piece together how, exactly, the Sonex was travelling at the time of impact. With all that equipment around, it should have left a pretty obvious trail as it disintegrated.

Ron Wanttaja

[1600vw]

We had a set of posts cross. As I mentioned there, I'm not really interested in pre-analyzing this early, but: The amount of damage to an aircraft (and its occupants) is exponentially related to the speed at which it hits. The amount of energy involved is related to the square of the speed...hit twice as fast, the airplane and occupants suffer four times as much.

Conversely, all things being equal, the less damage the airplane exhibits, the slower it was going. A lot of things affect this...a glancing first impact to slow the plane down, the nature of what it hits, etc. You can be killed on a bicycle; Frank Tallman had to have a leg amputated from tripping off a curb.

In all probability, the plane was travelling slowly when it hit. They may have had bad luck with the first thing they hit...but I think, typically, you see more tail cone damage in these cases as the plane tumbles. But, of course, the OTHER way it could hit slowly is vertically...deep stall or incipient spin.

We had a Fly Baby accident last year after an engine failure. It went down in a grove of trees. The NTSB report comments that the trees were damaged in a hole only slightly larger than the aircraft...in other words, it went straight in, probably stalled. In the pictures in the docket, the Fly Baby's fuselage is broken off just behind the cockpit and is remarkably intact. So are the wings, for that matter...but the forward fuselage is shattered. No fire, despite a fuel tank located above the pilot's legs right behind the engine.

So the NTSB investigators will be examining the debris trail, attempting to piece together how, exactly, the Sonex was travelling at the time of impact. With all that equipment around, it should have left a pretty obvious trail as it disintegrated.

Ron Wanttaja


Gotcha Ron. Thanks for this post.


Tony

[Mike M]

... In all likelihood, the vehicles were still owned by the manufacturer (e.g., pre-delivery).... Whether the trucks contributed to the severity of the accident or not, the fact that they were being sold to the Government is immaterial.

Well put. Those vehicles bring dollars into the Oshkosh and Wisconsin economy and provide quality jobs. If it wasn't those vehicles, it would be fire trucks or busses or whatever else the company builds. Those good folks live there and make their living there, doing that.

[rwanttaja]

In Tony's defense, this accident obviously hit him hard. It's natural for folks to seek a reason after a tragedy like this, and logic sometimes slips a bit.

Ron Wanttaja

[krw920]

Just to note, the trucks that were hit in this incident were NOT on airport property, but on private, Oshkosh Corp property just east of the airport.

[1600vw]

Just to note, the trucks that were hit in this incident were NOT on airport property, but on private, Oshkosh Corp property just east of the airport.

So this was an off airport incident. This did not happen within the fence area of Wittman airfield? Now I am understanding this a little better. I thought this was at Wittman. My bad. Sorry to cause such a ruckus.

Tony Sweet

[Glenn Gordon]

Just to clarify some of the geography....

4851
4852
4853

[1600vw]

Glenn Gordon thanks for the pics. I have been to oshkosh once in 2010. We drove in. For some reason I thought there was more open ground all around Wittman Field. Again sorry for the ruckus and my prayers to the family of both pilots.

Tony

[RickFE]

I saw the news yesterday and was just left with a hard to shake sunken feeling. I took the tour of the Sonex factory, hosted by Mr. Jerry Monnett while at Osh. His enthusiasm for Sonex was infectious and he was just an overall fabulous host for that tour. The tour was just a relatively short encounter but I have to admit that he left quite a positive impression on me regarding Sonex as a company and as an Ambassador of Aviation.

He was clearly a man that any family must have been extremely proud of.

Aviation has truly lost a great friend.

My condolences to all his family and friends.

[1600vw]

I saw the news yesterday and was just left with a hard to shake sunken feeling. I took the tour of the Sonex factory, hosted by Mr. Jerry Monnett while at Osh. His enthusiasm for Sonex was infectious and he was just an overall fabulous host for that tour. The tour was just a relatively short encounter but I have to admit that he left quite a positive impression on me regarding Sonex as a company and as an Ambassador of Aviation.

He was clearly a man that any family must have been extremely proud of.

Aviation has truly lost a great friend.

My condolences to all his family and friends.


Amen...

[rwanttaja]

NTSB Preliminary Report is out:
-----------------------------------------------
NTSB Identification: CEN15FA249
14 CFR Part 91: General Aviation
Accident occurred Tuesday, June 02, 2015 in Oshkosh, WI
Aircraft: MONNETT JOHN T JR SONEX SA, registration: N123SX
Injuries: 2 Fatal.
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

On June 2, 2015, about 1520 central daylight time, a Monnett Sonex SA experimental amateur-built airplane, N123SX, impacted unoccupied vehicles, after departing the Wittman Regional Airport (OSH), Oshkosh, Wisconsin. Both private pilots were fatally injured. The airplane was substantially damaged. The airplane was registered to and operated by Sonex Aircraft LLC, under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight which operated without a flight plan. The local flight was originating at the time of the accident.

According to OSH tower personnel, the airplane departed runway 9 from the intersection of runway 9 and runway 13. After clearing the airplane for takeoff, the tower controller focused their attention on inbound traffic and did not witness the accident.

The accident site was located 0.25 miles east-northeast of the departure end of runway 9. The airplane came to rest on unoccupied vehicles located on Oshkosh Corporation's property on a general heading of 220 degrees. The engine separated from the airplane and was located on the ground in front of the airplane. All major components remained attached to the airplane. The airplane was transported to a secure facility for further examination.
----------------------------------------------------------------------------------
With normal flow, the Factual report will be out in 8-12 months. The Factual report will summarize the evidence, without coming to a conclusion. It will be available on the NTSB web page. The final report, the Probable Cause, will be issued several months later after the meeting of the Board. At that time, the full report (including witness reports, etc.) will be placed in the docket for public access.

Ron Wanttaja

[rwanttaja]

NTSB Final Report is out.

http://app.ntsb.gov/pdfgenerator/ReportGeneratorFile.ashx?EventID=20150602X70621&AKey=1&RType=Final&IType=FA

Ron Wanttaja

[1600vw]

It looks like the turbo could have been an issue or caused this. So sad. They also say if just maybe they would have used the complete runway we would not be talking about this. Again very sad. Thanks for the update Ron.

[Joda]

It looks like the turbo could have been an issue or caused this. So sad. They also say if just maybe they would have used the complete runway we would not be talking about this. Again very sad. Thanks for the update Ron.

For those of you who don't know, I worked for Sonex during the time of this accident. I had just returned from 25 hours of cross country in the accident airplane. I flew it down to Florida for the Sebring and Sun N Fun events. The airplane had been flown only one other time since returning from Sun N Fun that spring. I helped Jeremy and Mike push the airplane out before the accident flight. I personally checked the oil and the fuel, and watched them taxi out and do the run-up. All was normal at that time.

I did not witness the takeoff, and it seems that nobody else did either. No eye witnesses have ever come forward at any rate. Jeremy was notorious for doing that intersection takeoff when the wind was from the east, as it was a long taxi from Sonex (on the very east side of the airport at OSH) to the far end of Runway 09. The intersection that they departed from is almost exactly half-way down the 6000 ft+ runway.

To get to my point, I was also the Sonex factory representative who assisted the FAA and NTSB with their on-site investigation the day after the accident. I personally turned the wrenches as we carefully evaluated the impact-damaged engine. One of the things we focused on was the turbo. The turbo housing was fractured on the compressor side, forcing the compressor housing to physically jam the turbine wheel. As soon as we dismantled the intake manifold to the point that this pressure was released, the turbine wheels and shaft turned freely. There was no failure of the turbo that was apparent other than the physical impact damage. The wording of the factual and final reports don't adequately illustrate this, which Sonex is disputing. Hopefully the report will be corrected to reflect what we actually found on-site.

Unfortunately, we will never know what actually happened that day. There are a few mysteries that we will never solve, but the lesson that can be learned (and it's not a new one) is that it is a mistake to leave usable runway behind you, regardless of what you "think" you'll need. Take that lesson to heart, and fly safely.

[martymayes]

I did not witness the takeoff, and it seems that nobody else did either.

Joe, do you know how the NTSB was able to determine takeoff ground run was ~1700 feet?

[Joda]

Joe, do you know how the NTSB was able to determine takeoff ground run was ~1700 feet?

There was apparently some GPS data that they were able to recover from the data card on the MGL instrument that was installed in the aircraft. Unfortunately, the instrument either didn't record any of the engine parameters, or the data was lost during the impact.

I question that statement as well, as that would be far beyond normal for a Sonex, especially the turbo, even with two people aboard. I had quite a bit of time in that aircraft, and I know it's takeoff performance was very good.

It's unfortunate that there were no eye witnesses that could verify what actually occurred during the takeoff run. That is just one of the mysteries that we'll probably never have an answer to.

[martymayes]

Thanks -

[rwanttaja]

Joe, I appreciate how hard this must be. There are two sections of the NTSB report where, perhaps, you might provide some insight.

From the wreckage and impact section:

The engine's turbocharger could not be rotated by hand. Disassembly of the turbo found static marks corresponding to compressor blades without any smearing or deformation of the blades. Disassembly of the turbo found that the bearing housing was cracked.

To a layman like myself, the "without any smearing or deformation" implies it was not turning at impact. Test and Research section seems to echo this, but there is mention of damage which might imply it was turning (I underlined that portion):

Impact marks were located at the upper and aft portions of the compressor housing surface. The impact marks were relatively distinct and discrete consistent with little relative motion between the blades and the housing at the time of impact. Corresponding blade damage was observed on the compressor wheel. Six of the compressor blades had radial cracks that emanated inward from the outer edges. The cracks were all associated with deformation of the blade where the airfoils between the cracks and the blade tip were bent toward the pressure face of the blade (toward the direction of rotation). Both the compressor wheel and turbine wheel turned together freely within the center housing when either wheel was rotated by hand.

My layman's interpretation of this is that the lack of smearing/little relative motion was a result of the engine failing for other reasons (e.g., if the engine is windmilling, the turbo's not spinning quickly). The bent blade tips were a reflection of the idle rotation. This, the fact that everything turned freely after impact distortion was relieved, indicates to me that the turbo wasn't directly a cause.

Ron Wanttaja

[Joda]

Ron,

Your interpretation is exactly correct in my view. It does appear that the turbo shaft wasn't turning, or was turning very little, at the time of impact. It is also true that, as I mentioned before, once the impact damage was relieved, the turbo shaft turned freely. There was no obvious evidence of any sort of in-flight failure of the turbo. Whatever happened, there was no tell-tale evidence that could be discerned by after-accident inspection of the engine.

Joe