Dornier’s Do-29: A STOLV Ground Breaking Aircraft

October 24th, 2007
Raul Colon
PO Box 29754
Rio Piedras, Puerto Rico 00929

Most of the early data collected on Short and Vertical Take-Off and Landing characteristics and systems were collected during Dornier’s Do-29 STOL and VTOL Research Program. The Do-29 program was commenced by West Germany’s Air Force with the intention of applying the collected data to the design and development of their next generation of military transport aircraft and help in the developmentsof Germany’s first true fighter project since the end of World War II. In order to keep cost down, engineers at Dornier decided to utilize a tested airframe for the new programme. They selected the proven Do-27 fuselage. The idea, beside the cost savings, was to utilize a strong enough airframe that could handle the expected weight of the heavy wing structure needed to house the engine vectoring system. The first example of the 29 was rolled out of the production line in the summer of 1958. Its airframe, although it was a Do 27’s fuselage, was modified with an extra fin structure below the tail to improve the aircraft’s low speed control characteristics. A larger fin and rudder structure were also incorporated on the fuselage for control purposes.

The aircraft’s cockpit was built to house one crew with a Martin-Baker Ejection System seat. The cockpit sat in the fuselage’s forward area and gave the pilot an excellent view of the rotating engines mechanism. Another modification to the original 27 fuselage was the installation of two external stiffeners on each side of the frame, plus three on the bottom of the airframe. The stiffeners were implemented to provide the airframe with an added shock-absorbing system to compensate for the expected frame shock caused by the oscillatory forces emanating from the propellers. The 29 had the same high set undercarriage of the 27 aircraft, which gave the Do-29 adequate clearance for the propellers and was sturdy enough to absorb the expected heavy landing forces associated with STOL and VTOL operations. A fixed single tail wheel; located at the bottom-rear of the airframe was installed. After altering the airframe and incorporating its new wing structure, the next phase of the project was the selection of the power plant. Dornier engineers selected the United States Avco Lycoming engines. Two of these new engines were installed on each wing structure near the main fuselage.


Frame Dimensions

Length: 31’-2”
Wing Area: 235 sq ft
Wing Span: 43’-4”
Maximum Take-Off Weigh 5,500lb


Engine System: Two 270hp Avco Lycoming GO480-B1a6 piston engines
Propellers: Two opposite-rotating three bladed Hartzell propellers
Maximum Attainable Speed: 180mph
Stalling Speed: 47mph
Take-Off Distance: 50’-0”

The propellers were designed to rotate in opposing directions in order to cancel out the generating torque. The first prototype of the Do-29 took to the air for the first time in December 1958 and performed as expected. Dornier’s test pilots found quickly that they could adapt to the aircraft’s unique flying characteristics. Two addition prototypes were eventually built. The overall programme objective, the acquisition of data related to STOL and VTOL operations was achieved. The Do 29 programme was never intended to be a full production project but its goal of being a stepping-stone design for Germany’s new military transport plane was achieved when Dornier unveiled its Do-31 STOL-VTOL transport aircraft, although this aircraft, as the Do 29 before, never made it to the production line, it did gather enough information to enable other countries such as Great Britain, to incorporate the collected data on their own STOL-VTOL programmes. Today, one of the three Do-29 prototypes sits at the prestigious Helicopter Museum located at Buckeburg, Germany. In the end, the Do 29 was indeed a groundbreaking aircraft.