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ASH25 |
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ASH25 |
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 TWO SEATER OF A NEW DIMENSION  Flying Open Class Competitions in a two-seater? The ASH 25, being the series production version of the AS 22-2, offers outstanding performance and on top of that the advantage of a second pilot.
The New Wing: The airfoil was modified in the aileron area and the span was increased to 25 m - promises further performance improvement in the low speed and high speed range. Being made almost exclusively out of carbon and aramid fibers (Kevlar), this high performance glider offers adequate useful load, sufficient for even two heavier pilots. Likewise the permissible C.G. range was selected such that also different cockpit loads present no problem. The ASH 25 can be flown two-seated up to a take-off mass of 750 kg (1654 lbs) and in this configuration the water ballast affects the C.G. position only imperceptibly. But also for weak weather onditions the ASH 25 offers an adequate wing loading with m/s = 38 kg/m (two-seated). The experience with the ASW 22 has shown that a glider with an aspect ratio of over 37 requires more wing loading than a 15 m glider. The flight testing of the AS 22-2 has demonstrated that the impressive flight characteristics of the ASW 22 can be transferred to a two-seater. The wing with its HQ17 airfoil and its flap kinematik provides agreeable and safe characteristics; e.g. this flap mixer system permits extremely steep and easily controllable landing approaches and the stick forces are low. The landing gear, high and sprung, as well as the dihedral of the wing help to the good landing characteristics. Despite of some changes compared to the AS 22-2 fuselage, the fuselage shape of the ASH 25 still discloses the affinity to the fs 31 made by the Akaflieg Stuttgart. This fuselage geometry with its contracted tail boom stands out for a relatively low aerodynamical drag. So the goal is achieved: to develop a two-seater which offers comfortable room for two pilots, without any significant performance loss compared to a single-seater. DESIGN SPECIFICATI0N Glider made from fiber-reinforced plastics, midwing with T-tail, flaps, retractable landing gear and water ballast. FUSELAGE CRP / SRP (Kevlar) monocoque fuselage with roomy safety cockpit. Rubbershock-mounted, retractable landing gear with 380 x 150 tire, retraction mechanism has counter spring for ease of operation. Hydraulic disc brake which is connected to the airbrake lever. in flight adjustable rudder pedals. Optimum cockpit ventilation through intake in the fuselage nose with continuously adjustable outlets, one on the front canopy frame and the others through directionally-adjubtable fresh air nozzles for both pilots. TOST C.G. tow release coupling. Infinitely variable speed trim, lockable by a stick key. CANOPIES The full-vision plexiglass canopies are hinged fore and aft (same system as ASK 21). The two-part canopy system was chosen because it gives the advantage of an excellent fit and tight sealing with all temperatures- On the left side sliding window with additional airecoop. Canopy frame with tongue and groove type sealing. INSTRUMENT PANELS The front instrument panel is made to hinge upwards with the canopy; even when the canopy is open, the instruments are still covered. When the canopy emergency jettison system is operated, the canopy together with the instrument panel coaming can be removed and the instruments are easily accessible. The rear instrument panel is not hinged to the canopy, but offers sufficient leg room for a safe emergency exit. WING Cantilever, four-part wing with new developped laminar airfoil and boundary layer control at the wing underside. The wing surface is a carbon fiberglass - hard foam sandwich. Wing spars with carbon fiber caps. Metal dive brakes on the upper wing side (airbrake paddles with spring-loaded caps). Rubber bellows are fitted at the push rods in order to seal the wing. Wing assembly is straightforward with a conventional tongue and fork spar extension secured with two large, easily insertable, cylindrical main pins. Relatively low weight of each wing part. No wing part is heavier than those of 15 m Class gliders. WATERBALAST Electrically operated waterballast system with automatic connections. Easy maintenance because of removable waterbags. Filling through two drain outlets under the wing. Ballast capacity: approx. 2 x 60 kg in the outer wing. CONTROL SURFACES T-tail (elevator with stabilizer). Stabilizer in CRP-sandwich-construction. Vertical fin in GRP-sandwich -construction because of the VHF-antenna radiation. All control surfaces and flaps are new-technology sandwiches of Aramid / fiber-reinforced plastics with a hard foam core which gives extremely light and stiff control surfaces. CONTROL, CIRCUITS AND FITTINGS Aileron, elevator, flaps and dive brakes are actuated by means of push rods running in ball-bearings. Quick-closing connectors without loose parts are fitted at the control linkage rigging points. Automatic elevator connection. The rudder is actuated partly ' by rods and partly by steel cables. All push rods are supported in roller bearings or in linear ball race guides. This provides the lowest possible actuating forces for the pilot and guarantees comfortable, non-fatigueing flying. Some of the bellcranks are of welded steel construction, the remaining bellcranks are machined from Duraluminium. BOARD EQUIPMENT AND ACCESSORIES Static pressure vents (for the A.S. 1. ) in the fuselage tail boom left and .right. Pitot, static pressure and TE-compeneation through 3-way-nozzle (multi-probe) in the fin. VHF antenna in the fin. Flight monitoring instruments as required can be installed in the instrument panels. Threaded bushings at the canopy frame left & right for possible fixing of camera mountings. seat cushion and storage pocket. POWER-PLANT - in the ASH 25 M The development of a new conception for the power-plant has solved many of the known problems with retractable engine units. Because of the foldable drive belt the engine could get a stationary installation in the fuselage. This has a particularly positive effect on the size of the exhaust silencer. Furthermore, it provides an improved support of all components of the power-plant. The entire power-plant can be removed after undoing only the three screw mounting attachments. The C.G. of the power-plant is below the front mounting attachment point which means that in the case of a crash landing the pilot is protected against the propeller tower- The power supply is provided by two batteries with a total of 14 Ah which are fitted in the inner wing. ENGINE The rotary engine was developped by the renowned manufacturer NORTON MOTORS, Great Britain, and it is outstanding for its low power-to-weight ratio and its remarkable smooth running. The manufacturer has succeeded in solving typical "Wankel-type" problems. The Beals are the latest state of the art technology and through the forced air cooling it was possible to solve the problem of the rotor overheat. ENGINE DATA: Single rotor engine, with liquid cooled housing and with forced air rotor cooling. Carburetted with dual electronic ignition, firing 2 plugs with electrical starting and 18 amp Generator. TECHNICAL DATA  TYPE ASH 25 ASH 25 M |
