Wing spar failure?

[DJE22]

I recently read there have been extremely few known Wing spar failure’s in Mooney aircraft. 
anyone here have actual stats in that?

(mooney down in Mn with fatalities today…RIP friends)

report of wing folded back 

[chriscalandro]

If you watch the video it certainly looks like the right wing is not in place. 
 

After reading the details it’s hard to argue that a parachute system wouldn’t have resulted in a better outcome. 

[DJE22]

@chriscalandro,  I did not see a video. Did you?

[carusoam]

 

[chriscalandro]

25 minutes ago, DJE22 said:

@chriscalandro,  I did not see a video. Did you?

I did. 

[DJE22]

1 minute ago, chriscalandro said:

I did. 

Now saw that someone did a freeze frame and definitely looks like wings folded…flat spin?

[ArtVandelay]

Now saw that someone did a freeze frame and definitely looks like wings folded…flat spin?

Or it hit power lines or tree tops. We only see the last 30’.

[LANCECASPER]

Earlier news report said he struck a house.

[Hank]

32 minutes ago, LANCECASPER said:

Earlier news report said he struck a house.

After pancaking beside the driveway, looks like the plane flipped towards the house, flames everywhere make it difficult to see. May have hit it, maybe just burned it some. You know how "initial reports" go.

[Nippernaper]

My understanding of how structural overload failures typically occur in other makes, like malibus and bonanzas, is that in a high g loading situation, the first thing to fail is the horizontal stabilizer, which fails downward. The plane then pitch-poles (for lack of a better term) nose downward, and the wings also fail in a downward direction due to the sudden, huge aerodynamic loads in the negative direction. This seems to be a very different situation.


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[Bartman]

I am certain this is an artifact. Look at the vertical stabilizer. There are two superimposed images and the vertical stabilizer is elongated and there are two images of the stripe at the top. 

[A64Pilot]

10 hours ago, chriscalandro said:

If you watch the video it certainly looks like the right wing is not in place. 
 

After reading the details it’s hard to argue that a parachute system wouldn’t have resulted in a better outcome. 

I woud bet money that any flight profile that would cause structural failure in a Mooney would be well outside of a parachutes envelope.

I believe but am not certain that an SR-22 at normal cruise is outside of the deployment envelope due to speed, some who know will say I’m sure.

It’s my understanding  that the CAPS is excellent for those that run out of fuel or maybe get scared in IMC, but I think on the fastest model. it’s deployment airspeed is less than 140 kts.

Edited August 8, 2021 by A64Pilot

[aviatoreb]

40 minutes ago, Bartman said:

I am certain this is an artifact. Look at the vertical stabilizer. There are two superimposed images and the vertical stabilizer is elongated and there are two images of the stripe at the top. 

I agree.  Just as likely a digital video artifact.

How many of us have taken stills, or videos, looking forward through our own spinning pops only to have them look like the props were dramatically curved.

[PT20J]

44 minutes ago, A64Pilot said:

I woud bet money that any flight profile that would cause structural failure in a Mooney would be well outside of a parachutes envelope.

I believe but am not certain that an SR-22 at normal cruise is outside of the deployment envelope due to speed, some who know will say I’m sure.

It’s my understanding  that the CAPS is excellent for those that run out of fuel or maybe get scared in IMC, but I think on the fastest model. it’s deployment airspeed is less than 140 kts.

According to my SR22 POH, max demonstrated speed for CAPS deployment is 133 KIAS. I recall one deployment near Truckee years ago where there was a loss of control in icing and the parachute separated from the airframe because it was deployed at high speed.

Skip

[PT20J]

I've never seen one actually documented. The story related to me years ago by a factory engineer is that the Bonanza had a few spar failures on Ralph Harmon's original design and so when he metalized the Mooney, he way over-built it. I was told that more modern calculations showed it would fail at around 10 g, but I have no idea if Mooney ever tested one to destruction.

Skip

[DJE22]

1 hour ago, aviatoreb said:

I agree.  Just as likely a digital video artifact.

How many of us have taken stills, or videos, looking forward through our own spinning pops only to have them look like the props were dramatically curved.

@aviatoreb and @Bartman and @Hank, are you saying / thinking that the appearance of the wings folding upward (in the freeze framed pics) is inaccurate ?

I also noted someone else suggested the aircraft may have hit power lines or trees before com into into the pic, causing the wing(s) to fold.

Regardless, doesn’t it seem like a flat spin?

[EricJ]

22 minutes ago, DJE22 said:

Regardless, doesn’t it seem like a flat spin?

No, the airplane is moving forward with no apparent angular momentum.

[A64Pilot]

1 hour ago, PT20J said:

I've never seen one actually documented. The story related to me years ago by a factory engineer is that the Bonanza had a few spar failures on Ralph Harmon's original design and so when he metalized the Mooney, he way over-built it. I was told that more modern calculations showed it would fail at around 10 g, but I have no idea if Mooney ever tested one to destruction.

Skip

I’ve heard a similar story many years ago.

‘I’d bet myself that the wing is strong enough so that something else will break first, horizontal or empennage maybe?

On edit I’m sure you have heard the story of them braking the fixture when they tried or test to destruction, that’s not really all that uncommon.

‘At Thrush we broke the fixture when we tried to pull a wing spar box to failure. we had already completed the pull to ultimate and the spar wasn’t any good for anything so why not?

We only pulled the main spar assy, not need to waste a whole wing on the test we were doing. We took the wing spar cap life limit from 29,000 hours to 60,000 hours and increased gross weight from 6,000 lbs to 10,500 lbs, so of course there was a lot of structural substantiation involved.

Edited August 8, 2021 by A64Pilot

[aviatoreb]

1 hour ago, DJE22 said:

@aviatoreb and @Bartman and @Hank, are you saying / thinking that the appearance of the wings folding upward (in the freeze framed pics) is inaccurate ?

I also noted someone else suggested the aircraft may have hit power lines or trees before com into into the pic, causing the wing(s) to fold.

Regardless, doesn’t it seem like a flat spin?

Not saying I know either way but - It might be - just saying it’s plausible and it’s still very very early.  You need a special high speed camera to accurately capture fast moving objects.

[carusoam]

As far as digital pics/video vs. reality goes…

Expect the plane, post crash will reveal a whole spar OR a folded one…

Don’t be surprised either way… more info is needed… and will be forthcoming…

 

The fuel Spraying forward looks very similar to standard wings, hitting the standard ground, in a standard way…

Lets invite our weather guy to the discussion… @Scott Dennstaedt, PhD (looking for recent weather info regarding wind shear and a Mooney accident, in Minnesota… kind of near thunderstorms…)

Best regards,

-a-

[wiguy]

 The cause of that MN crash is very unlikely to be a ‘wing spar failure’. As planes go, it was newer than many. One could take a brand new plane & induce wing failure if that was the goal.

  The wings folding is more likely to be attributed to severe airframe over stress. 

[steingar]

I now know of two failures, one of which was in the middle of a thunderstorm, the other in Minnesota a few days ago.  That crash makes it pretty obvious that you can break the Mooney spar.  It also shows what you have to do in order to break it.  I have no doubt that if I do a full power dive at Vne and pull back as hard as I can I'll break the airplane, possibly the spar.  Below extreme movements like that I'm not in any way worried about it.

My other airplanes, the wings were held on by a couple bolts.  

[jgarrison]

41 minutes ago, steingar said:

I now know of two failures, one of which was in the middle of a thunderstorm,

Rocket in California. M20J in Louisiana. Both encountered massive thunderstorms.

[DXB]

1 hour ago, jgarrison said:

Rocket in California. M20J in Louisiana. Both encountered massive thunderstorms.

I believe this is the K in California:  https://aviation-safety.net/wikibase/36780  It sounds like horizontal stabs departed first due to overspeed-induced flutter.  What snapped the spar isn't totally clear from the description. The NTSB narrative talks about icing conditions but does not mention a thunderstorm.  

Anyone have a link to the J model accident?

Then there's the recent event with the  M20M in Minnesota - precise events and exactly when the spar broke remains unclear, but primary cause appears likely to be loss of control in IMC.  

 

 

[Jerry 5TJ]

If you lose your horizontal stabilizer why would you care if your wing spar is intact?