A Cessna P-210 was the last iteration of the Cessna Pressurized Centurion airplane model, at least Cessna thought so.

The Pressurized Cessna P-210 was equipped with a Continental TSIO-520 piston engine and a three bladed propeller. It cruised at mid-altitudes and a little faster than the standard 210.

Then someone got the idea to change the engine and install an Allison, now Rolls Royce, turbine engine instead.

The propeller was changed as well and the STC was sold to a number of P-210 owners.

It was faster, flew higher, and had a higher rate of climb than the factory airplanes.

But it seems that good is never good enough so a new STC was developed, not by Cessna, that installed an MT, German built light weight five-bladed scimitar shaped propeller on this turbine conversion.

The one thing that seems to have escaped the thinking of designers and modifiers is that a five bladed propeller creates much more drag in the event of loss of engine power than either a four or three bladed propeller, in fact so much drag that the airplane wants to stop in mid-air right now in the event of loss of power.

Now it isn’t clear yet whether this crash was caused by the engine or propeller or both but surveillance video clearly shows the airplane climbing out and then suddenly rolling over on one wing as if it stalled suddenly.

With a properly operating engine and propeller, it is virtually impossible to stall a converted Silver Eagle  P-210 in this manner.

One problem with an airplane with a lot of after-market STC’s (Supplemental Type Certificates) is that the certification requirements are not as stringent and the testing not as rigorous as a factory-built airplane that is certified as an entire airplane.

So, given that a few MT propeller equipped airplanes have recently crashed, a TBM 700 in Ohio and this one at the least recently, a very careful look has to be taken of this propeller and its aerodynamics and functionality, especially if there is a loss of power for any reason.

The Wolk Law Firm extends its condolences to the families who are suffering so much from their losses.

May the memories of those who have passed be a blessing.

Arthur Alan Wolk


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