Dan Ford's books
For print editions of Dan's books, go here      For the e-books, go here


Horten flying wing under tow by oxen
Reminiscent of the way Mitsubishi's prototype Zero fighter was towed from the factory to the airfield by a team of oxen, German fuel shortages forced the use of oxen "tugs" for a demonstration flight of the H XII motor glider.

'Spirit of Thuringia'

Spirit of ThuringiaHorten Ho 229 Spirit of Thuringia: The Horten All-Wing Jet Fighter (Andrei Shepelev & Huib Ottens)

Available at Amazon.com and Historic Aviation

This handsome book gives the short version of the Ho/Go-229's development, at least as compared to David Myhra's three-volume version. Neither of the co-authors is a native English speaker (though Huib Ottens caught the aviation bug from the Biggles books as a lad), and it shows in their somewhat labored text. Italics are used too often (Luftwaffe, Professor, Fraulein, all of which long ago passed over into English), and there's a slavish obedience to German titles (it really wasn't necessary to introduce the sibling as "Fraülein Dip.phys. Gunilde Horten"). Nevertheless, it's worth having, and less expensive and weighty than the Myhra books. Here are my notes from a first reading:

The aerodynamacist "Ludwig Prandtl ... believed, based on wind tunnel tests, that it was impossible to safely stall a tailless aircraft. In February 1943, a demonstration flight of the H IIId was arranged ... in which Heinz Scheidhauer proved these fears groundless. Scheidhauer performed various manoeuvres with the motorglider--pulling the nose up until the airspeed was zero, then putting it down to regain speed and control response--showing no tendency to enter a spin. These manoeuvres were all flown at the dangerous height of no more than ten metres [good grief!] and were all safely executed without any loss of height." (p.30, p.33)

The H IX (as the plane was designated by the company) was designed with an aft spoiler and a brake parachute "to prevent the touchdown-delaying 'floating' during landing." (p.43) Because of the aircraft's low priority, systems were incorporated from elsewhere: the nose wheel assembly on the first two protypes was a He-177 tail wheel; the main landing gear was modified from the Bf-109G; other parts came from a damaged Me-210 and a captured B-24 Liberator bomber. (p.44)

"Control harmonization is an issue with the all-wing configuration due to its high raio of lateral inertia to longitudinal inertia." That is: the wingspan is huge and the fuselage almost nonexistent. "This ratio depends on the actual design geometry, decreasing with higher sweep angles and increasing with higher aspect ratios." That is: it helps to have the wings swept to the rear; it hurts to have long, skinny wings. The problem was worst on the H IX V1 glider version. (p.47) "For a warplane like the H IX, its lateral to longitudinal inertia ratio of 5:1 could have rendered control harmonization--and hence accurate aiming--difficult." A fix would be to depress both rudder pedals, thus deploying both drag-rudders and steadying the aircraft. (p.48)

The next design stage was the H IX V3. "The control system of the V3 was simplified with single-stage brake rudders and elevons with the latter's inner section now used only as flaps. The rearmost permissable c.g. position could only be attained on the V3 by the addition of 300 kg of ballast weight in the nose." The first armed prototype would be the H IX V6. (p.61)

The book is done magazine style, or perhaps it would be better to say in the style of the Schiffer publishing company: large format, two columns of type, huge quantities of black-white photos, splendid line drawings, and computer-done color views of the exterior and cockpit. I highly recommend it for all-wing buffs, even for those who already own some or all of the Myhra books.

Click here for more on the Horten all-wings. And for more on this subject, see the reviews of The Horten Brothers and Their All-Wing Aircraft and The Horten 229 Retrospective and Technical History

Question? Comment? Newsletter? Send me an email. Blue skies! -- Dan Ford