TWITT Archive

Additional Materials

Courtesy of Nikolas Korakis

Akaflieg Karlsruhe AK-X
The AK-X flying wing sailplane is being built by the students of Akaflieg Karlsruhe in Germany. The AK-X is promising to be the next big thing in high performance Standard Class (15 m) sailplanes. The AK-X is in fact a continuation of the legendary SB-13, exploiting the invaluable experience gained by its predecessor. The Akaflieg Karlsruhe expects a performance in par with larger tailed sailplanes (18 m??) without the (admittedly few) shortcomings of the SB-13. Let's hope that they succeed. The Akaflieg posts a Youtube video reporting the progress of the project almost every month. Here is the link:
And also find below the site of the Akaflieg Karlsruhe, where more interesting material regarding the AK-X can be found ( this material is in German, but a translator will do the job): AK-X | Akaflieg Karlsruhe

Horten -
Stability Considerations in Sweptback Wings

R. Horten's "Stability Considerations in Sweptback Wings," in which he presents his theory of making the highly tapered sweptback flying wing platform (which is the configuration that he used for his flying wings throughout his life) tip-stall proof and spin proof (the "C-Point" theory). Strangely, this is a paper I hadn't read before (I discovered it a couple of months ago). All of those fellows who have studied K. Nickel's book "Tailless Aircraft in Theory and Practice" will be familiar with the theory of R. Horten presented in the attached paper, because in fact K. Nickel was closely cooperating with him. K. Nickel himself also in his book "Tailless Aircraft in Theory and Practice" gives credits Horten when explaining the theory behind the "C-Point" and its significance in flying wings. The even more fascinating thing, is that we still use his theory even today, especially us RC aeromodellers, when locating the correct CoG of a new flying wing: the well known graphical chord construction in fact finds the Mean Geometric Chord, the 25% of which is the "C- Point" or "Geometric Neutral Point "!!! (See this link for how to do it: Flying wing CG calculator.)

Ho II Test Flight
Includes detailed notes by Reimar Horten.

Ho XVc Pappenheim
Nikolas provided this video of a demonstration flight of the Ho XVc Pappenheim.

Ashkenas -
Tailless Aircraft Performance Improvements with Relaxed Static Stability

This I. L. Ashkenas paper "Tailless Aircraft Performance Improvements with Relaxed Static Stability." This paper is fascinating because in fact it is a continuation of Northrop's work on flying wings, solves the problems arising with the stability configured flying wing, and clearly gives hints on how the B-2 bomber operates.

Klingberg Wing Mk II
Rol Klingberg is now trying to finish and fly his second flying wing rigid hang glider, the "Klingberg Wing MKII." He occasionally presents his progress through YouTube videos on his channel (