Ivoprop, the history behind the IVOPROP, and Ivo Zdarsky it's designer.

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Ivo Zdarsky and his propeller.

Picture this - your at an airshow selling ultralights and someone comes up to you out of the blue, that can hardly speak English, dressed like an escapee from the "flower power generation" - and asks you to try out his propeller.

Well that is how I met Ivo Zdarsky the owner of IVOPROP. He literally walked out of the crowd and invited me try out his prop on my Buccaneer Amphibian. I sat down and had a talk with him for quite a while to get some background on this "prop" and designer.

It seems IVO had recently escaped from the Czech Republic, by secretly building himself a trike, mounting an old car engine to it, building himself a prop, teaching himself how to fly, and navigating himself and his craft across the "Iron Curtain" to freedom. While this may sound far fetched - it is the truth, in fact the plane, engine, and prop are on display in museum which features "escape vehicles."

Anyway back to the story - so I bolt this three blade prop on to my little single place Buccaneer XA powered by a 503 Rotax. IVO sets it up for me - the prop was ground adjustable something up until then I had never even heard of being available for ultralights. A couple of twists of the blade and the rpm is dialed into where I am comfortable with it.

The prop is real smooth and quiet, but the real difference is the performance - my climb rate increased by over 200 feet per minute and cruise speed at 5500 rpm was about 6 miles per hour faster. Needless to say I was impressed. IVO told me to fly with it for a couple of days, he would get back to me. Now remember IVO had never seen me before, I did not have a commercial display I was just there selling from my plane on the flight line - I could have flown away, or left the show for home and he wouldn't have a clue how to find me!

Well I flew on his prop for two or three days - then set out on a little cross country up to the Florida Flying Gators up near Leesburg. Arriving I decided to retract the gear and set down on one of the many ponds surrounding the field, and do some touch and goes.

Up until this time I had been flying on an "Ultraprop" a great little 2/3/4 blade composite prop, that was very smooth, quiet and nearly indestructible, with the last being the most important. When you land or take off on one of the old XA's the prop really takes a beating from the spray coming off the hull.

Well the spray came off the hull into the new "IVOPROP" and literally ate it for lunch, during my first touch down and fast taxi across the pond. The vibration was so bad that I had to shut the engine down and paddle to shore! A friendly "Gator" gave me a lift back to Sun N Fun, where I picked up my old prop for the return trip.

Next day IVO shows up smiling from ear to ear and asks "how the prop works" - a little sheepishly I bring out what is left of his prop and hand it to him. He can't believe it. He sits down with me and I recant the above. Ivo and I part company and the next time I see him is at Oshkosh.

According to friends he has been looking for me for several days - he has another prop he wants me to try out! This time I only have my two place Buc with a 532 Rotax 65 hp. No problem, he again dials it in and I take off. Not wanting to waste anytime I fly over to the seaplane base and set down on the lake, set up for a fast taxi on the step and listen as the water goes through the prop during high speed turns on the step.

No vibration, no loss of performance - just to be safe I bring it into shore and give it a thorough check - I had brought my old prop just in case! I fly back and am greeted by Ivo again with that childish grin of his.

For the next couple of years I buy quite a few props from IVO, the delivery is good and quality excellent. Then I get several orders in where the props are "different." They vibrate, and need balanced, the hubs are not as "finished." Then I read of a report of a failure in Florida where the prop caused an engine to come off a plane.

I immediately contact all of my customers - tell them to stop flying until I can get some more information. I get in touch with friends in Florida and am told that while the prop had failed it is being attributed to "improper torque" of the blades.

None the less I check out ALL the props I have sold. The last batch of 5 props - have several areas that I "question." Two areas of major concern to me are in the hub and at the base of the ball of the blades.

I call IVO - to find that "he has left the company" - in fact when I placed the last couple of orders I was always told he was "unavailable." I am told to talk to the NEW owner, rather than talk I decide to bring the hubs and blades to Oshkosh and see the NEW owner face to face!  On arriving at his display I find him demonstrating the strength of his NEW prop via the use of a prop bolted to a car engine, and a set up that allows the prop to contact a steel bar while spinning.

I bring out my blades and hubs, in private, the new owner looks at the props and indicates that while "there is nothing wrong" with the "hubs or blades" he will replace them as a sign of goodwill. He then takes the blades from me and proceeds to use the blades in his demonstration.

Several months went by, when I still hadn't received any new blades (I replaced the customers props with GSC props with leading edge protection) I called was put in touch with the owner, who said he would send them out right away. About 3 weeks later I received 1 prop, which I had to pay the shipping, handling and taxes on - and a BILL for the prop!

To this day that is all I have ever received - from the NEW owner and NEW company WARP DRIVE!

I lost touch with IVO until Sun N Fun the next year, when all of a sudden there he is, grinning at me with a NEW style of prop in his hands. Gone are the hub, ball and socket and weight!

(While IVO has never told me what happened - the rumour is that once the tooling and molds were "in house" the NEW OWNER became the designer!

Thus no need for IVO. It was funny to hear a very similar story from Full Lotus, a set of floats are asked for to demonstrate at the show - only to be copied, by the same individual, and in the copy if you looked real close you could still see the Full Lotus LOGO!!!)

Anyways back to IVO. The new prop uses a torsional steel rod imbedded in the blade for adjustment. As pressure is applied to the base the rod twists the blade! With all blades supplied with a stainless steel leading edge for "water protection."

Adjusting the blades can be done without loosening any bolts, and no gauges are needed. You turn a shaft in the middle of the prop and all blades are adjusted at the same time, to the same pitch!

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