No thunderstorm on this one, but over gross. That was the MT prop demo plane going to a show, no less.

https://app.ntsb.gov/pdfgenerator/Repor ... l&IType=FA

Another which hit unforecast turbulence.

https://app.ntsb.gov/pdfgenerator/Repor ... l&IType=FA

Another one that hit turbulence inadvertently.

https://app.ntsb.gov/pdfgenerator/Repor ... l&IType=FA

And here's another one.

https://app.ntsb.gov/pdfgenerator/Repor ... l&IType=FA

Another one where the parts came apart in the air.

https://app.ntsb.gov/pdfgenerator/Repor ... l&IType=FA

In flight break up, but probably doesn't count, non pilot at the controls.

https://app.ntsb.gov/pdfgenerator/Repor ... l&IType=FA

Another breakup.

https://app.ntsb.gov/pdfgenerator/Repor ... l&IType=FA

Tail came off.

https://app.ntsb.gov/pdfgenerator/Repor ... l&IType=MA

Another breakup.

https://app.ntsb.gov/pdfgenerator/Repor ... l&IType=MA

Another breakup.

https://app.ntsb.gov/pdfgenerator/Repor ... l&IType=FA

Another breakup.

https://www.ntsb.gov/_layouts/ntsb.avia ... 2157&key=0

Another breakup.

https://www.ntsb.gov/_layouts/ntsb.avia ... 5600&key=0

Another breakup.

https://www.ntsb.gov/_layouts/ntsb.avia ... 5189&key=0

So 13 breakups, of which maybe 11 "count"? Those are just the ones I found for the 690s. I didn't search the other turbine Commander models. Not a single one of the above entries has the word "thunderstorm", and only one has the word "convective" (the first one, MT prop demo plane).

Damn, that was depressing.


Not really.

If you fly a Commander, and there's a chance of turbulence, you had better slow down. That big wing will generate tons of lift if you aren't careful.

ADs and spar mods may have mitigated some of the risk, but that big wing that makes flying the Commander so docile is not without negatives.

Mike C.

Other types have similar circumstances occur to them and they don't come apart as much.

Commanders simply don't have as much structural margin as other aircraft so when things go wrong, it can come apart.

The scary incidents are the ones where they hit unexpected turbulence. Since that could occur at any time, one wonders how you prepare for that.


The author listed them because they exist. It was claimed it was a myth, so I went and got the data. And that was only for 690 models, not all the high turbine Commanders.

I wonder why you think dissing the MU2 makes the Commander break up history acceptable. Pushing down one type doesn't elevate another.

Mike C.

I can't figure out which one I am missing.

“Safety” conveniently missing !

Not when I sit in the left seat.

Safety is never something you can build into the plane, it comes with the pilot.

Mike C.

Not when I sit in the left seat.

Safety is never something you can build into the plane, it comes with the pilot.

Mike C.

Really? This is coming from a guy who just post a bunch of phony reports to spin a personal narrative!

I was comparing aircraft you didn't like it so you turn attack dog.

Did I post anything about the MU2 that was inaccurate?

Whatever issues were found with Commanders decades ago has been addressed and fixed.

Can the same be said of the MU2? There have been several recent MU2 accidents that hit close to home here. Has there been any fixes introduced to prevent further losses?

NTSB entries are "phony reports"?

Mike C.

Claiming all those accidents were caused by structural failure is phony.

That would be like saying the MU2 accident in Canada that killed all on board was caused by structural failure since the airframe failed on contact with the ground!

Structural failure was the Result not the cause.

I'm not advocating that TC 690's are or aren't safer than Mu2's but I don't think its reasonable not to acknowledge that there have been a lot of in flight breakups in the Commanders. Can Hoover fly them acrobatically for 20 years and not spill water? Sure, but a dozen or so pilots, some in cruise, hit turbulence and came down in pieces. As with everything there are trade offs. A less robust airframe will have improved margins OEI. Sounds nice. Given the reliability of turbine engines, statistically speaking, there is less chance of me ever being in a OEI situation in the 15 critical seconds where I will have to use superior pilot skills to survive than being in cruise flight hitting turbulence that could break my plane. If the wing or tail breaks no amount of training or piloting will help.

"JUST BEFORE BOTH HORIZONTAL
STABILIZERS AND THE RUDDER SEPARATED FROM THE AIRCRAFT"

"TYPE OF ACCIDENT PHASE OF OPERATION AIRFRAME FAILURE: IN FLIGHT IN FLIGHT: NORMAL CRUISE"

"TYPE OF ACCIDENT PHASE OF OPERATION AIRFRAME FAILURE: IN FLIGHT IN FLIGHT: NORMAL CRUISE FIRE OR EXPLOSION: IN FLIGHT IN FLIGHT: NORMAL CRUISE"

"TYPE OF ACCIDENT PHASE OF OPERATION AIRFRAME FAILURE: IN FLIGHT IN FLIGHT: CLIMB TO CRUISE"

"Occurrence #1: AIRFRAME/COMPONENT/SYSTEM FAILURE/MALFUNCTION
Phase of Operation: UNKNOWN
Findings
1. WEATHER CONDITION - TURBULENCE
2. (C) WING,SPAR - OVERLOAD
3. (C) DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED - PILOT IN COMMAND
4. (F) OVERCONFIDENCE IN PERSONAL ABILITY - PILOT IN COMMAND
5. (F) OVERCONFIDENCE IN AIRCRAFT'S ABILITY - PILOT IN COMMAND
6. WING - SEPARATION"

"Findings
9. DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED
10. WING - OVERLOAD
11. FUEL SYSTEM,TANK - OVERLOAD"

"Findings
13. (C) DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED
14. HORIZONTAL STABILIZER ATTACHMENT - OVERLOAD
15. VERTICAL STABILIZER ATTACHMENT - OVERLOAD
16. STABILIZER - SEPARATION"

"Findings
6. (C) DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED - PILOT IN COMMAND"

"Findings
7. (C) DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED
8. STABILIZER - OVERLOAD
9. STABILIZER - SEPARATION
10. FLT CONTROL SYST,RUDDER - OVERLOAD
11. FLT CONTROL SYST,RUDDER - SEPARATION"

"Findings
2. WING - FAILURE,TOTAL
3. HORIZONTAL STABILIZER ATTACHMENT - FAILURE,TOTAL
4. VERTICAL STABILIZER ATTACHMENT - FAILURE,TOTAL
5. (C) AIRSPEED(VA) - EXCEEDED - PILOT IN COMMAND
6. (C) DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED - PILOT IN COMMAND"


"Findings
5. (C) DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED
6. HORIZONTAL STABILIZER ATTACHMENT - OVERLOAD
7. HORIZONTAL STABILIZER ATTACHMENT - FAILURE,TOTAL
8. VERTICAL STABILIZER ATTACHMENT - OVERLOAD
9. VERTICAL STABILIZER ATTACHMENT - FAILURE,TOTAL"

"Findings
2. (C) AIRFRAME - OVERLOAD
3. DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED - PILOT IN COMMAND"

"Findings
1. (F) WEATHER CONDITION - TURBULENCE
2. AIRFRAME - OVERLOAD
3. (C) DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED - PILOT IN COMMAND
4. (F) AIRCRAFT WEIGHT AND BALANCE - EXCEEDED - PILOT IN COMMAND"

Having twice the performance is nice!

If robust means overbuilt you can keep it.

With the Commander and MU2 having very similar weights how do you explain the performance difference?

Whatever issues the 690s had were addressed many years ago. Similar to what other manufacturers have had to do. The conquests tail issue comes to mind first. That problem is now history.

I imagine it's safe to say most GA airframes have lost aircraft in cruise.




The most recent loss in cruise I can think of was the MU2 that disappeared in the Bahamas.

Perhaps you should consider the possibility and do your best to avoid. The Commander pilots in many of those old reports did not have the tools we have today and some just didn't care enough to look.

I have no doubt that you are well trained, the SFAR requires it. In the SFAR training they describe just the engine out event you are concerned with.

The procedure is to land on the runway if it's long enough or to land off airport if you are below I think 50 or 75 ft with gear in transit! You will need all your pilot Kung foo skills on that one.

Its not what you would do in a Commander. In a Commander or just about any other TP you would just fly straight out then come back for a landing.

I'm not advocating that TC 690's are or aren't safer than Mu2's but I don't think its reasonable not to acknowledge that there have been a lot of in flight breakups in the Commanders. Can Hoover fly them acrobatically for 20 years and not spill water? Sure, but a dozen or so pilots, some in cruise, hit turbulence and came down in pieces. As with everything there are trade offs. A less robust airframe will have improved margins OEI. Sounds nice. Given the reliability of turbine engines, statistically speaking, there is less chance of me ever being in a OEI situation in the 15 critical seconds where I will have use superior pilot skills to survive than being in cruise flight hitting turbulence that could break my plane. If the wing or tail breaks no amount of training or piloting will help.

"JUST BEFORE BOTH HORIZONTAL
STABILIZERS AND THE RUDDER SEPARATED FROM THE AIRCRAFT"

"TYPE OF ACCIDENT PHASE OF OPERATION AIRFRAME FAILURE: IN FLIGHT IN FLIGHT: NORMAL CRUISE"

"TYPE OF ACCIDENT PHASE OF OPERATION AIRFRAME FAILURE: IN FLIGHT IN FLIGHT: NORMAL CRUISE FIRE OR EXPLOSION: IN FLIGHT IN FLIGHT: NORMAL CRUISE"

"TYPE OF ACCIDENT PHASE OF OPERATION AIRFRAME FAILURE: IN FLIGHT IN FLIGHT: CLIMB TO CRUISE"

"Occurrence #1: AIRFRAME/COMPONENT/SYSTEM FAILURE/MALFUNCTION
Phase of Operation: UNKNOWN
Findings
1. WEATHER CONDITION - TURBULENCE
2. (C) WING,SPAR - OVERLOAD
3. (C) DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED - PILOT IN COMMAND
4. (F) OVERCONFIDENCE IN PERSONAL ABILITY - PILOT IN COMMAND
5. (F) OVERCONFIDENCE IN AIRCRAFT'S ABILITY - PILOT IN COMMAND
6. WING - SEPARATION"

"Findings
9. DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED
10. WING - OVERLOAD
11. FUEL SYSTEM,TANK - OVERLOAD"

"Findings
13. (C) DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED
14. HORIZONTAL STABILIZER ATTACHMENT - OVERLOAD
15. VERTICAL STABILIZER ATTACHMENT - OVERLOAD
16. STABILIZER - SEPARATION"

"Findings
6. (C) DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED - PILOT IN COMMAND"

"Findings
7. (C) DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED
8. STABILIZER - OVERLOAD
9. STABILIZER - SEPARATION
10. FLT CONTROL SYST,RUDDER - OVERLOAD
11. FLT CONTROL SYST,RUDDER - SEPARATION"

"Findings
2. WING - FAILURE,TOTAL
3. HORIZONTAL STABILIZER ATTACHMENT - FAILURE,TOTAL
4. VERTICAL STABILIZER ATTACHMENT - FAILURE,TOTAL
5. (C) AIRSPEED(VA) - EXCEEDED - PILOT IN COMMAND
6. (C) DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED - PILOT IN COMMAND"


"Findings
5. (C) DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED
6. HORIZONTAL STABILIZER ATTACHMENT - OVERLOAD
7. HORIZONTAL STABILIZER ATTACHMENT - FAILURE,TOTAL
8. VERTICAL STABILIZER ATTACHMENT - OVERLOAD
9. VERTICAL STABILIZER ATTACHMENT - FAILURE,TOTAL"

"Findings
2. (C) AIRFRAME - OVERLOAD
3. DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED - PILOT IN COMMAND"

"Findings
1. (F) WEATHER CONDITION - TURBULENCE
2. AIRFRAME - OVERLOAD
3. (C) DESIGN STRESS LIMITS OF AIRCRAFT - EXCEEDED - PILOT IN COMMAND
4. (F) AIRCRAFT WEIGHT AND BALANCE - EXCEEDED - PILOT IN COMMAND"

Hmm, any PC12 that come to mind? (where the cause wasn't a spiral dive or similar).