The Bede XBD-2 was an experimental short takeoff and landing (STOL) aircraft, with several novel features such as structural use of glass-fibre and aluminium honeycomb, a suction boundary layer control (BLC) system and fuselage-mounted twin engines driving a pusher configuration, shrouded single propeller. The sole example flew in the early 1960s in the United States.
Bede aircraft was formed to develop an STOL aircraft of novel construction, incorporating boundary layer control. They placed the design study with the Department of Aerodynamics at the University of Maryland. The boundary layer was controlled with a suction system via 160,0000 upper wing and aileron surface holes, with diameters ranging from 0.020 to 0.029 in (0.51 - 0.74 mm). Aluminium honeycombs were used throughout the fuselage as structural elements. The XBD-2 was powered by a pair of flat-sixpiston engines mounted inside the fuselage, driving a single pusher configurationpropeller, turning within a circular shroud.[1]
The wing of the XBD-2 had an aspect ratio of 9 and 5° of dihedral. It was built around an aluminium box spar, was aluminium skinned and carried sealed all-metal ailerons. A 14 in (356 mm) Joy blower pulled air through the pinholes in the surfaces, venting it in the fuselage to cool the engines. Sealed flaps smoothly changed the wing camber and increased its area by about 15% when extended.[1]
Apart from its use of aluminium honeycomb, the front part of the flat-sided fuselage was conventional, with a cabin with space to seat four, though mostly filled with instrumentation. Aft, two 145 hp (108 kW) Continental O-300 engines were mounted one above the other. They drove the rear propeller shaft through ten V-belts via Sprag clutches to avoid engine speed synchronisation problems. The rear fuselage tapered to a vertical wedge with the propeller shaft emerging at its top. The circular shroud was attached to the fuselage by the fixed triangular fin mounted on the top of the fuselage, the triangular tailplane and a short boom at the bottom. The propeller rotated close to the shroud's leading edge; the shroud was intended partly to reduce propeller tip losses and also to act in the place of conventional stabilizing surfaces. The fin resumed above the shroud and carried the top of a high aspect ratio rudder behind the shroud's trailing edge, its bottom end attached to the tailboom, with a midpoint cutout to allow for elevator movement. The elevator was supported by tailplane extensions beyond the shroud, similar to that of the fin.[1][2]
Structurally, the shroud was a glass-fibre shell surrounding an aluminium spar and filled with polyurethane foam. The control surfaces were conventionally constructed from aluminium sheet. The XBD-2 had a fixed tricycle undercarriage, with wheels enclosed in fairings. The main legs were glass-fibrecantilevers, unusual at the time.[1]
After the XBD-2 first flew on 26 July 1961[1] it was flight tested and slightly modified to simplify future production.[3] It was intended to lead to the BD-3, which would have been a six-seater with bigger engines, more use of honeycomb panels, retracting undercarriage and a laminar flow wing,[1] but this was not built.[2]
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Not to be confused with Bede BD 2 The Bede XBD 2 was an experimental short takeoff and landing STOL aircraft with several novel features such as structural use of glass fibre and aluminium honeycomb a suction boundary layer control BLC system and fuselage mounted twin engines driving a pusher configuration shrouded single propeller The sole example flew in the early 1960s in the United States XBD 2Role Experimental aircraftNational origin United StatesManufacturer Bede AircraftFirst flight 26 July 1961Number built 1Developed into Bede BD 3 Contents 1 Design and development 2 Aircraft on display 3 Specifications 4 References 5 External linksDesign and development EditBede aircraft was formed to develop an STOL aircraft of novel construction incorporating boundary layer control They placed the design study with the Department of Aerodynamics at the University of Maryland The boundary layer was controlled with a suction system via 160 0000 upper wing and aileron surface holes with diameters ranging from 0 020 to 0 029 in 0 51 0 74 mm Aluminium honeycombs were used throughout the fuselage as structural elements The XBD 2 was powered by a pair of flat six piston engines mounted inside the fuselage driving a single pusher configuration propeller turning within a circular shroud 1 The wing of the XBD 2 had an aspect ratio of 9 and 5 of dihedral It was built around an aluminium box spar was aluminium skinned and carried sealed all metal ailerons A 14 in 356 mm Joy blower pulled air through the pinholes in the surfaces venting it in the fuselage to cool the engines Sealed flaps smoothly changed the wing camber and increased its area by about 15 when extended 1 Apart from its use of aluminium honeycomb the front part of the flat sided fuselage was conventional with a cabin with space to seat four though mostly filled with instrumentation Aft two 145 hp 108 kW Continental O 300 engines were mounted one above the other They drove the rear propeller shaft through ten V belts via Sprag clutches to avoid engine speed synchronisation problems The rear fuselage tapered to a vertical wedge with the propeller shaft emerging at its top The circular shroud was attached to the fuselage by the fixed triangular fin mounted on the top of the fuselage the triangular tailplane and a short boom at the bottom The propeller rotated close to the shroud s leading edge the shroud was intended partly to reduce propeller tip losses and also to act in the place of conventional stabilizing surfaces The fin resumed above the shroud and carried the top of a high aspect ratio rudder behind the shroud s trailing edge its bottom end attached to the tailboom with a midpoint cutout to allow for elevator movement The elevator was supported by tailplane extensions beyond the shroud similar to that of the fin 1 2 Structurally the shroud was a glass fibre shell surrounding an aluminium spar and filled with polyurethane foam The control surfaces were conventionally constructed from aluminium sheet The XBD 2 had a fixed tricycle undercarriage with wheels enclosed in fairings The main legs were glass fibre cantilevers unusual at the time 1 After the XBD 2 first flew on 26 July 1961 1 it was flight tested and slightly modified to simplify future production 3 It was intended to lead to the BD 3 which would have been a six seater with bigger engines more use of honeycomb panels retracting undercarriage and a laminar flow wing 1 but this was not built 2 Aircraft on display EditThe sole XBD 2 is mounted on outdoor display at the entrance to Manitowoc County Airport 4 Specifications EditData from Jane s All the World s Aircraft 1962 63 1 General characteristicsCrew one Capacity four total Length 23 ft 8 in 7 22 m Wingspan 37 ft 6 in 11 42 m Height 12 ft 5 in 3 78 m Wing area 150 0 sq ft 13 94 m2 Airfoil Gottingen 549 Max takeoff weight 3 300 lb 1 497 kg Powerplant 2 Continental O 300 A 6 cylinder horizontally opposed air cooled 145 hp 108 kW each Propellers Hartzell constant speedPerformance Maximum speed 204 mph 328 km h 177 kn at sea level Cruise speed 179 mph 288 km h 156 kn maximum at 65 power at 9 000ft 2 740 m Stall speed 42 mph 68 km h 36 kn with BLC Without BLC 64 mph 57 kn 106 km h Service ceiling 21 000 ft 6 400 m service Rate of climb 1 050 ft min 5 3 m s Take off run less than 300 ft 90 m Take off distance to clear 50 ft 15 25 m under 500 ft 152 m Landing distance from 50 ft 15 25 m under 500 ft 152 m References Edit a b c d e f g Taylor John W R 1962 Jane s All the World s Aircraft 1962 63 London Sampson Low Marston amp Co Ltd pp 170 1 a b Bede XBD 2 Retrieved 7 May 2012 Taylor John W R 1966 Jane s All the World s Aircraft 1966 67 London Sampson Low Marston amp Co Ltd p 185 XBD 2 on display Retrieved 7 May 2012 External links EditGottingen 549 airfoil Retrieved from https en wikipedia org w index php title Bede XBD 2 amp oldid 1108912505, wikipedia, wiki, book, books, library,
