Junkers T 29
| Industry | Aerospace |
|---|---|
| Headquarters | Germany |
The Junkers J 29 was an experimental two-seat monoplane with a single engine, developed in Germany during 1925. It marked the inaugural use of the Junkers Doppelflügel (double wing) control surfaces, a feature that was subsequently implemented successfully on the Junkers Ju 52.
Design and development
The J 29 was designed as a low-wing cantilever monoplane, utilizing Junkers' characteristic duralumin tubular framework combined with corrugated metal skinning. Its wing, exhibiting a straight-tapered planform, incorporated the patented Junkers Doppelflügel system—full-span ailerons hinged beneath the trailing edge, creating a slot that improved control effectiveness. During flight, these surfaces operated as conventional ailerons but could be deflected downward to serve as flaps for landing while still providing lateral control.
The fuselage had flat sides with a rounded upper decking and was powered by a Junkers L1a inline engine, whose cylinder heads were partially exposed. The cockpit accommodated pilot and passenger seated side by side in an open arrangement, shielded by a longitudinal arch reminiscent of a roll bar; this distinctive feature led to the aircraft’s nickname Bügeleisen (flat iron). The tail assembly included a blunt vertical fin and a broad, deep rudder that moved within elevator cutouts; neither control surface featured horn balancing. The fixed landing gear followed Junkers' typical design: shock-absorbing main legs attached near the forward wing root and braced beneath the engine, connected via a centrally hinged cross axle supported by a V strut under the fuselage.
Only two units of the J 29 were constructed, with the initial flight occurring in April 1925. Promoted under the designation T 29 to imply its training role, these aircraft primarily functioned as testbeds for the double wing system later adopted on models such as the G 28, Ju 52/3m, and Ju 87.