Ralph Rissmiller, Flight Test Pilot – TKS Testimonial

23rd October 2017

Ralph Rissmiller lives in Wichita, Kansas and flies throughout the United States. He is a DER/ODA UM Flight Test Pilot who has done the full spectrum of ice protection systems down through the certification aspects to get them into service. Ralph has flown flight tests in natural ice, tanker ice and dry air ice. He is the owner of a 1981 Beechcraft A36 Bonanza with inadvertent TKS Ice Protection.

Ralph Rismiller’s Beechcraft A36 Bonanza

How did you get started in aviation?

I started flying when I was 14 years old. After a stint in the Air Force, got into the flight test side and stayed with it for the last 38 years.

Why did you choose TKS?

In this particular case, I didn’t make the choice. It was already installed on the airplane when I purchased it. At the time, there was no other ice protection system available for the airplane.

What does TKS do for your mission?

Since I have an inadvertent system, I don’t plan or dispatch into any known ice environment. But it allows me the flexibility that, should unexpected ice occur, it gives me an out.

Aero Commander 500 Flight Test with Beechcraft King Air 200 Tanker

Have you had any memorable experiences with TKS?

I’ve done testing on other airplanes with TKS, and those have included some pretty significant icing encounters. Expanding on that, those events occurred during the certification tests for the approval of the TKS Ice Protection System on several different aircraft, all of which were successful and certified. There was a variety of Part 25 of Part 23 airplanes.

I can speak to one test that we did when we were testing the Aero Commander 500. The company operated out of the same base where a fleet of booted 208s were. The Aero Commander pilots reported that a lot of the 208 guys were drooling over the fact that the Aero Commander was clean of ice, and the 208 had a lot of residual ice on it, which kind of supported Cessna’s decision to change to TKS for the 208 ice protection system. TKS is different in its approach. Yes, it’s expendable. But it does either keep off or remove ice, whereas a boot only removes ice that has accumulated and you have to have some in order to remove. You also tend to have more residual ice with the boot.

Have you flown in aircraft with other ice protection systems?

I’ve had a lot of experience with various other ice protection systems, mostly while conducting certification tests of them. My experience includes electro-impulse de-icing, pneumatic boots, TKS, bleed air, and electrothermal systems. An evaporative bleed air system tends to be the gold standard, if you will, today.

TKS in my opinion is more effective than pneumatic boots. Additionally, you don’t have to tend to it all the time. You turn it on and let it run. TKS prevents ice accumulation rather than shedding it after you accumulate ice, similar to a running wet bleed air system. Boots don’t have runback. TKS has a little more runback than a running wet bleed air system, because it truly is running back. With the running wet bleed system you can actually get accumulation of rivulets of ice streaming aft on the wing upper surface. With TKS, normally any runback just continues on off the wing, since it’s been mixed with the TKS fluid solution already.

Learn More About TKS for the Beechcraft Bonanza


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