BFW M.29
| Industry | Aerospace |
|---|---|
| Founder | Willy Messerschmitt |
| Headquarters | Germany |
The BFW M.29 was a low-wing, twin-seat monoplane powered by a single engine, developed by the German company Bayerische Flugzeugwerke (BFW). Designed by Willy Messerschmitt, it was intended to compete in the 1932 Circuit of Europe air races.
As a cantilever monoplane, the M.29 featured a wing span slightly reduced compared to its predecessor, the BFW M.23. It incorporated an enclosed tandem cockpit that seamlessly integrated into a dorsal fairing stretching back to the vertical fin. The tail assembly included a broad-chord rudder and an all-moving tailplane mounted with bracing near the fin's apex. The undercarriage was cleanly faired with spats and employed a cantilever design. Additionally, the wings could be folded at hinges located at the wing roots, folding back alongside the fuselage sides.[1]
Development
In the late 1920s, aeronautical engineer Willy Messerschmitt had created several successful racing aircraft. Notably, various BFW M.23 models secured victories in the Circuit of Europe or Challenge International de Tourisme competitions in both 1929 and 1930. These achievements enhanced Messerschmitt's reputation and increased demand for his designs. Following the announcement of the 1932 Circuit of Europe, Messerschmitt embarked on developing a more advanced aircraft to seize this opportunity, culminating in the creation of the M.29.[2]
The M.29 was conceived as a new design focused on sports and touring aviation.[2] Its high-speed capabilities made it particularly appealing to business professionals aiming to reduce travel time and private owners valuing efficiency. However, it was recognized that racing aircraft often faced limited appeal among private pilots due to challenging high-speed landing requirements.[2] Consequently, one of the primary objectives for the M.29 was to operate effectively across an unusually broad speed range, surpassing that of comparable aircraft at the time. To fulfill this, it possessed a significant power reserve allowing flexible engine throttling; it was also claimed that its elevated cruising speed rendered it more fuel-efficient than other sport planes.[2] Comprehensive aerodynamic testing conducted at Gottingen demonstrated that the M.29 could reach speeds up to 260 km/h (161.6 mph) while maintaining landing speeds between 55 and 60 km/h (34 to 37 mph).[2]
Achieving low landing speeds was facilitated by flaps and slots installed along the wing’s trailing edge, enhancing safety during slow flight phases. The ailerons’ angle of attack lagged behind flap deflections, further contributing to control stability.[3] Flap operation was managed via a simple cockpit lever that automatically retracted if excessive control pressure occurred, thereby protecting wing structural integrity. When fully deployed, the wing’s behavior resembled that of a Zanonia wing.[4] To prevent airflow separation at high angles of attack, wingtips were slightly twisted. The combined effectiveness of flaps and ailerons enabled pilots to perform stalled landings without needing to level out beforehand.[3]
Constructed entirely from wood with fabric-covered ribs attached to a single spar, the wing was fully cantilevered.[3] Its leading edge planking and spar provided torsional rigidity critical for managing vibrations at elevated speeds. The wing featured pronounced tapering and a specialized airfoil profile designed for favorable aerodynamic characteristics.[3] A six-degree dihedral was present on the lower wing surface. With medium thickness and optimized shape, its drag coefficient at small angles of attack approached those typical of contemporary racing planes.[3] Utilizing flaps effectively yielded an equivalent lift-to-drag ratio exceeding 200.[3]
The wing’s flexible profile combined with streamlined aircraft components—particularly the landing gear—contributed significantly to achieving its wide speed range.[3] When flaps were retracted for high-speed flight, the wing maintained a fixed center of pressure profile that minimized torsional stress even at maximum velocities.[3] Each wing was attached to the fuselage at three points.[3]
The fuselage featured an almost rectangular cross-section with a triangular braced frame made from tubular steel covered in fabric.[5] This design ensured aerodynamic smoothness while providing structural strength where wing spars connected via robust girders. The landing gear attachment points were similarly reinforced.[5] The steel tube structure extended aft into the vertical fin.[5]
Above the fuselage sat an enclosed cabin accommodating both pilot and passenger.[5] This cabin design offered excellent visibility during critical phases like landing; semi-circular canopies over each cockpit could be tilted back if desired.[5] Transparent side panels illuminated the interior and enhanced external sightlines; these panels could be lowered to open the cabin sides. For emergency egress, the entire fuselage top could be swiftly removed via a single handle; occupants also had access to backpack parachutes.[5]
The pilot’s instrument panel included an altimeter, compass, turn indicator, clock, speedometer, tachometer, ignition controls, oil temperature gauge, oil pressure gauge, and fuel gauge. Instruments were arranged so that those related to engine operation were grouped separately from navigation tools. Illumination was provided through transparent cabin windows.[6] The cabin featured adjustable padded seats with armrests; communication between occupants was possible when closed due to proximity and design.[7] The rudder bar was adjustable as well. Behind the seats lay a compact baggage compartment.[7]
Tail surfaces were constructed entirely from wood covered in fabric.[5] A mechanical stabilizer operated by the pilot replaced a conventional horizontal stabilizer, enabling stable flight across various speeds—a relatively rare feature at that time even among aircraft equipped with adjustable stabilizers.[5]
Landing gear employed cantilevered pneumatic struts designed to absorb landing shocks effectively.[5] These struts utilized nearly full fuselage height to provide stroke lengths between approximately 30 and 40 cm (12–16 inches). Wheels were fitted with low-pressure balloon tires and brakes; both struts and wheels were aerodynamically faired. The robust undercarriage—including a metal tail skid—was considered capable of enduring stalled landings.[8] The skid featured rubber chord damping and could swivel during taxiing maneuvers. Overall, landing gear design aimed to minimize aerodynamic drag.[9]
Flight controls offered excellent maneuverability with well-balanced control forces.[4] Controls were user-friendly and designed for easy maintenance with many parts quickly replaceable. A combination of cables and push rods operated via a control stick managed control surfaces.[9] Optionally, dual controls could be installed and disengaged simply by rotating the pilot’s control stick head.[9]
Powerplants ranged from air-cooled engines delivering between approximately 100 and 150 horsepower.[9] Common engines included a closely cowled Siemens-Halske Sh14a seven-cylinder radial producing around 112 kW (150 hp) designated M.29a or an air-cooled inverted inline Argus As8R racing variant delivering similar power labeled M.29b.[1] While starting methods differed—the Argus requiring manual hand cranking versus compressed air for the Siemens—both engines were mounted on tubular steel supports.[9] Smooth sheet elektron cowlings divided into sections allowed easy access for maintenance of engine components such as magnetos and carburetors; all tubing used flexible rubber materials.[9]
Fuel tanks holding up to approximately 120 liters (32 gallons) were positioned in front of the firewall within the fuselage and supplied fuel by gravity feed.[9] These tanks were removable for servicing or replacement. Depending on engine type installed, oil tanks were either located beneath or above in positions separated from direct engine heat exposure.[10]
Operational history
A total of four aircraft, encompassing both versions, were delivered for evaluation shortly before the racing event commenced on 27 August 1932. Early assessments praised the aircraft for its speed and agility. Unfortunately, within a few days, one plane broke apart mid-flight, resulting in the pilot's death, and another was similarly lost during its landing approach. In the latter incident, pilot Reinhold Poss managed to parachute to safety, though his observer did not survive. Poss reported that the failure initiated at the tailplane and then extended forward. Consequently, all M.29 models were grounded, causing them to miss the competition, while reinforcements were made to the tail assembly.
Following these structural improvements, the remaining racing aircraft—augmented by at least one additional M.29—completed flights successfully. Photographic records confirm that at least six units of the M.29 were manufactured.
Variants
Note[11]
- M.29a: Powered by a 112 kW (150 hp) Siemens Sh 14a radial engine
- M.29b: Equipped with a 112 kW (150 hp) Argus As 8R inline engine
Specifications (M.29b)
References
Citations
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Bibliography
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