Examining In-Flight Breakups

[Ted]

The discussion regarding the possibility of the Seneca having an in-flight breakup recently got me curious as to the history of 310s, so I looked it up.

Since 1982, the NTSB database has 378 fatal accidents on 310s listed. Of those, 11 involved some sort of in-flight breakup (a bit under 3%). On the surface, this seemed high to me, until I read a bit deeper.

All 11 had pilot flying at night, in IMC, or both. 5 involved flight into thunderstorms. They pretty much allread the same - pilot got disoriented (or was in a thunderstorm), put in too great of inputs, and the tail fell off, sometimes the wings fell off as well.

The moral of the story I came away with was that history of 310s to date has only showed some sort of structural failure when the pilot provided inputs that overstressed the plane. The vast majority of fatalities read as you'd expect. Pilot got disoriented and lawn darted in, pilot ran out of fuel, pilot crashed into a mountain, instruction fatalities, Vmc, too slow/stall/spin, etc.

Anyone else looked at this topic for their aircraft type?

 

[Challenged]

Since 1982, it looks like there have been about 32 fatal accidents in Beech Sierra's. Similar to your information, the only in-flight breakups I can find of a Beech Sierra so far are spatial disorientation/loss of control/thunderstorms:

http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20060505X00515&key=1
http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20020729X01238&key=1

 

[flyingron]

I know of two in Navions. One was an airplane emerging from the bottom of a cloud most likely spatial disorientation by the pilot. The other involved the pilot getting liquored up and going out and doing some aerobatics.

http://www.ntsb.gov/aviationquery/brief2.aspx?ev_id=20070416X00423&ntsbno=LAX07LA118&akey=1

 

[DavidWhite]

3 Mooney 201s - all from flying into thunderstorms.

There has never been an in-flight breakup of a Mooney operating within its envelope - they have a 1 piece spar that is about the strongest in the fleet.

 

[Ted]

3 Mooney 201s - all from flying into thunderstorms.

There has never been an in-flight breakup of a Mooney operating within its envelope - they have a 1 piece spar that is about the strongest in the fleet.

Yeah, but they clearly have an issue with their tails.

 

[DavidWhite]

Yeah, but they clearly have an issue with their tails.

That actually tends to be where the failure point is.

 

[tmyers]

Yeah, but they clearly have an issue with their tails.

Yep, when they fall off someone keeps gluing them on backwards.

 

[Ted]

That actually tends to be where the failure point is.

Horizontal or veertical tail? The horizontal seems a common one, which makes sense since that's where people will pull too hard.

 

[X3 Skier]

Yep, when they fall off someone keeps gluing them on backwards.

Cheers

 

[DavidWhite]

Horizontal or veertical tail? The horizontal seems a common one, which makes sense since that's where people will pull too hard.

Horizontal.

 

[Skylane81E]

Horizontal.

Seems to me the hinge the tail swings on is a likely "weak" point

(Quotes used because weak is a relative term, plenty strong for normal usage)

 

[jesse]

There are 55 accident reports regarding Flybabies in the NTSB database 14 of those are in-flight breakups from wing failures. That means 25% of the reports are in-flight breakups and there are more in-flight breakups then there were accidents from engine failures. Although I would bet that many of the engine failure accidents never made it to an NTSB report. I doubt there has ever been an inflight breakup that hasn't received an NTSB report.

Of those wing failures:
- 50% of them involved aerobatics.
- Two of them have the spar carry through rot (wood)
- One was because someone forgot to put the spar carry pins in
- One was an improper repair from a previous accident
- One was a turnbuckle failure from corrosion
- One was caused by cracking by someone using solid flying wires (not as per the plans)
- One had the flying wire tension seriously improperly balanced

My thoughts:
I inspect things. I do not do aerobatics or do any high G loads. I keep the airplane stored inside. I also have a really good parachute

I personally believe that the Flybaby has a bit of a bad reputation mostly do to poor maintenance. It's always been about the lowest-cost airplane you could acquire but it still takes real money to maintain it. Too many people just get in them and fly them and let them sit outside and rot. No proper inspections really ever done. Too many years of that and one day your wings are going to fall off.