Ligeti Stratos

No no ...not a bi-plane!


Thanks to John Burford, previous hoster of, I got in contact with Ron Ligeti. Ron is the son of the designer of a small, but very remarkable airplane, the Ligeti Stratos.

(permission to use picture by Romeo F. Garcia)You will probably have noticed the connection between the two wings. This configuration is called a joined wing and a boxwing. Both are true.

"Hey, I saw something similar on your site and yet different.", you might think. Yes, you are right. The Sunny of Dieter Schulz looks a lot like it. Both benefit from the rigid structure of the wingtips being fixed to each other. But ...the Sunny is more basic and the front wing is at the top. Both have a prop in the rear, but the Stratos has the prop in a duct. The Sunny has covered alu framed wings, the Stratos has composite wings. You see, there are similarities but as much differences.

To date (28 Feb. 2004) there are three know versions of the Stratos.

  1. The prototype. Ron Ligeti writes the following about it: "it is still in airworthy condition and is the only one in existence, I have not flown it because if it is damaged I will have nothing. That is why I am building another one."
  2. The intended production version, which did crash taking the live of its designer, Charles Ligeti. The crash does not mean that the concept is not stable. Later more about the reason for the crash.
  3. The current work of Ron Ligeti. Ron is currently working on a new model. He is building this after his full-time job. He mentioned a aimed roll-out in mid 2005. Let us hope that we will see the beauty next year.

What were the differences between the two versions which already flew. Ron writes:
"The main changes of the production model to the prototype are:

  1. Full length elevator on the canard and full length aileron on the main wing(prototype had elevator aileron on canard - flaps aileron on main wing)
  2. experimental high lift devise- Channel/third wing along fuselage and into the duct
  3. dihedral removed from main wing
  4. Sandwich construction as opposed to foam core
  5. Side stick controls as opposed to center stick control
  6. fuselage shape modified for higher efficiency
  7. 4cyl Koenig engine instead of 3cyl Koenig engine
  8. a few other small details with it's construction"

I fear that the changes are a bit the reason for the crash. Ron writes: "The version that did crash (1987) was a production model that employed a highly experimental - high lift devise as well as other major aerodynamic changes that changed it's stability."

Luckily Ron Ligeti could found out what the reasons were for the accident. It is all told in another site. Sadly ...that site exists no longer. Anybody has a copy of that data?

OK, the prototype flew good. That is sure.

The things I like about the Stratos:

  • The use of tandemwings to create stability and a short span
  • The slender fuselage which holds both wings
  • Using a duct to improve the efficiency of the short propeller
  • The central landing gear to decline the drag and so improve the performance

  • (anno 2024) Sadly i heard that Ron stopped working on the new edition.