Hydroplum I

October 15th, 1982 Claude Tisserand put in building site a single-seat Hydravion out of plywood, genuine multiaxis ULM whose study began a few months earlier. Built in 10 months (600 hours) in a garage in the center of a Corsican village, the prototype was completed on August 15th, 1983. It was about a monoplane single-engined aircraft to braced high wing, the hull being arranged with an open station behind which a pylon received the aerofoil and an engine actuating a pusher airscrew. The empennage was supported by a back beam, passing under the propeller and of the side small baloons suspended under the wing ensured stability flood. The formula thus pointed out famous seaplanes, like the Dornier Wal.

The tests began on a hydroelectric storage reservoir: the chechmates of wind-bracing of the aerofoil plunging in water, of water projections damaged the propeller. The base of the chechmates was thus ducted. During its third test the prototype déjaugea prudently for a jump of chip of 300 Mr. Stable, the prototype had a tendency to prick which was corrected by modifying the chock of the stabilizer. The first real flight took place at the beginning of October in the gulf of St Florent, in Corsica, and revealed that the seaplane was centered too front. It was necessary to move back the battery to the maximum, to add 2 kg of ballast in the tail and to modify the chock of the wings to obtain a perfectly regulated apparatus.

During the winter the wings were advanced of 7 cm and the ballast of tail removed to rectify centering, the propeller and the exhaust of the engine changed, a hinged landing gear with back caster installed. May 26th, 1984 took place the first takeoff, on the ground of Ghisonaccia. July 2nd a test of overspeed caused a breakdown of engine to the top of the gulf of St Florent. Hydroplum behaved in perfect sailplane and was posed without difficulty on a calm sea. In September 1984 the single-seater was presented to Blois with the gathering ULM then with the Paris airshow between the May 29th and June 6th, 1985. Adding up approximately 35 hours of flight before an exit ramp in Corte causes its immobilization, the Hydroplum I did not know any commercial continuation. A score of plans were sold but only one seems to be completed.

Hydroplum I (a):

In 1992 Claude Tisserand, which sold its Hydroplum II with SMAN, takes again his Hydroplum I , which lost an end of wing during a road transport. The French regulation having changed meanwhile, the wing surface of origin was too important. It thus decided to cut the wing on other side, reducing surface to 12 m ², to remake entirely ducted masts, and to replace the floats of origin by floats of end of moulded plastic wing. The spoilers, the marine rudder and the caster postpones were also redrawn. These modifications were completed in August 1992, and the tests carried out since the beach of Marana, in the south of Bastia revealed a lengthening of the distance from lift-off but an improvement of the performances. After five hours of flight the seaplane was garaged for the winter… and was sold one year later to a Breton pilot who does not seem to have flown with since.

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