If you exclude thunderstorms like you do for the MU-2, you won't find many for the TC either. It's a myth.

Guys: This is why I love this board. Where else can we get such independent thoughts and critical application of facts on all brands so we can compare? No personal attacks. Differences of opinions, but none taken personally. Love it.

The C90 seems to be pretty close to the 421 profile also. Doesn't have the large nose compartment, but pretty close in performance and load carrying ability. My empty weigh is 6,113. My max gross at departure is 9,650. One can get a gross weight increase if willing to put on higher ply tires and pay for placards.

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.

In my own personal opinion, the lowest cost, reliable t-prop for application in my business is an early model ('01 - '06) Meridian. It fits 90% of my missions to a tee (<800nm out and back business trips with me and occasionally 1 passenger) and will also handle the short range family trips (2 adults, 2 kids and bags <600nm). With good performance (260 kts) and exceptionally reasonable fuel burn (36-38 gal/hr), roughly $15-20K annuals and almost no maintenance in between annuals and little / no calendar inspections, it's really difficult to beat on an overall cost per mile basis.

I continually run all-in cost of ownership #'s (acquisition, taxes, depreciation, fuel, mx, training, etc) on nearly every option of the pressurized twin piston and lower end turbine market and the Meridian always looks the most favorable overall. Note that I fly 50-60K nm per year so I need 200+ hours in a t-prop, which puts me well beyond the 100 hr inspections that many twin t-props have on a calendar year basis.

Some of the lower end twin t-props are in the ballpark of overall costs (Cheyenne I/II, Turbo Commander 6xx, MU2, Conquest I) and they do offer bigger cabins, more UL and space compared to the Meridian. However, the fuel burn is substantially higher, maint and reserves are significantly higher and at the end of the day, they are just old airframes. No matter what you do to these airplanes, the airframes are old and that aspect becomes evident in the maintenance but even more so in perception of myself and my passengers.

My 2012 SR22T feels new in every way and is exceptionally well received by every passenger that I've taken up in it. A Meridian also feels relatively new and is also received well by passengers. An airplane built in the 70's and 80's is always going to look and feel like an airplane built in the 70's and 80's.

Throw in the ease of transition and training compared to twins, good support, good user community, low depreciation (on the earlier models) and it's just a winner in my book.

Note this is just my perspective.

UL on my 1980 421C is 2,335 pounds.
206 gallons plus 1,000 pounds of payload.

Direct operating cost approximately 350 per hour.
Add hangar, insurance and annual expenses about 650 total.
My total cost for everything is about 65,000 per year for 100 hours.

More than half the the fleet is junk with a lot of differed MX. A good one is great and a bad one will be expensive.

Old turbines are the same, half the fleet will require a lot of MX. The dispatch reliability is not there for a lot them.

Here we come to real heart of the matter, I suspect. This is the true main reason we make the numbers skew in favor of the newer planes. Confirmation Bias. We want them, so we make the numbers work for that.

I don't think he funded the purchase of the plane he flies, so it is easy to talk about "cost of money" when you don't have to pay it yourself.

Mike C.

Well, no, things that exceed their actual limits break. When you exceed the design limits, you are using design margin, which doesn't mean it breaks necessarily.

I guess the polite way of saying it is that the Commander has minimal design margin. To build a big wing but manage the weight, it has to be built closer to the limits.


A number of the reports state "inadvertent" or "unforecast" turbulence. So when do you know you have to slow down?

This means just what I said, be careful in conditions where you might hit turbulence. This is also a capability limiter, you need to go slower in some conditions.

This all flows naturally from the big wing.


That's fair, though I would expect an MU2 subjected to the same abuse would not have come apart.


No, but seemingly far less often and with seemingly greater circumstances of cause, like in an actual thunderstorm, not just turbulence, in some cases in clear air.

Mike C.

I don't think he funded the purchase of the plane he flies, so it is easy to talk about "cost of money" when you don't have to pay it yourself.

Mike C.

The night is young.

What about opportunity cost?

Take the pissing matches offline please

x2