TYPE: Side-by-side lightplane/kitbuilt.

PROGRAMME: Design started 11 February 1989 (Storm 280 SI); construction of prototype started 24 November 1990; first flight March 1991; certified to Aero Club Italia ULM category. Production aircraft manufacture began 29 March 1993, first flight July 1993; first delivery August 1993.

CURRENT VERSIONS: Total of six versions currently available, both above and below ultralight weight limit; Storm 280 G, has tricycle or tailwheel landing gear, Storm 300 Special, introduced in 1997, has tricycle gear. The Storm Century development of the Storm 300 Special was introduced in 2000 and is available in tricycle and tailwheel versions. Other modifications include a lengthened engine cowling, increased fuel capacity using wing tanks, and a baggage compartment behind rear cabin. Additionally, the 119 kW (160 hp) Storm 400 Special (400SP) is a stretched version of the 300 with a stronger spar which has been developed for the US market; see Power Plant paragraph for deatils of engines. The Storm 280 E, 280 SI, 300, 300 Focus, 320 E, 400 Focus and 400TI are no longer available.
Storm 500: Introduced in 2001 in two versions (basic CLK and retractable-gear SLK); is full-four-seat version, available only in tricycle form.
Storm RG: First flown 2001; development of 400 with conventional tailplane and modified fin with dorsal fillet. First deliveries in 2002. Prototype being tested with winglets; not standard.
Cyclone: Military version of Storm RG; hardpoint under each wing. Cockpit glazing comprises fixed windscreen; rearward sliding canopy; and fixed rear windows. No known production.
Sea Storm: Unrelated design; see separate entry.

CUSTOMERS: By early 2003, over 650 Storms ordered, of which more than 250 were flying. Around 80 per cent are tricycle landing gear versions.

COSTS: Kits: Storm 280 €19,212; Storm 300 Special €18,954; Storm 400 Special €19,884; 500 CLK €21,898, 500 SLK €25,513. Complete: Storm 280 €61,045; Storm 300 Special €62,026; 400 Special €72,511; 500 CLK €73,905, 500 SLK €79,483; RG €68,000 (all 2003).

DESIGN FEATURES: Extensive use of modern materials and technology. All-aluminium fuselage and wings on 280 SI and 300 Special. Quoted build time for kits 600 hours.
Wing sections NACA 4415 (Storm 280 SI); GA 3OU-6135 Mod (Storm 300 Special). Thickness/chord ratio 15 per cent; 3o dihedral; 3o incidence.

FLYING CONTROLS: Manual. All-moving tailplane with anti-balance tab on most versions; no rudder tab. Storm RG has conventional horizontal tail. Balanced Frise ailerons on 70 per cent of span. Electric trim controls. Flap settings: 280, 10/20/32o; 12/25/38o on 300 and 400 series; all models have Fowler flaps.

LANDING GEAR: Main legs are cantilever sprung. Tricycle versions have tubular steel sprung nosewheel leg steerable ±40o. Tailwheel leg of Storm 300 is metal sprung with a solid tyre. Hydraulic disc brakes on mainwheels. Speed fairings can be fitted. Matco tyres; mainwheels 15x6.00, pressure 2.00 bar (29 lb/sq in); tailwheel (mainwheel in Storm 300 Special) 15 cm (6 in), pressure 1.80 bar (26 lb/sq in). Storm RG has 5.00-5 wheels on all legs; main wheels retract inwards, nosewheel rearwards. No doors.

POWER PLANT: Storm 280 G: One 59.6 kW (79.9 hp) Rotax 912 UL or 84.6 kW (113.4 hp) Rotax 914 flat-four four-stroke driving either a two-blade GT166-42 fixed-pitch propeller or a variable-pitch IVO-Prop or AR-Plast propeller; or one 59.7 kW (80 hp) Moto Guzzi driving a two-blade GM fixed-pitch propeller. Fuel capacity for 280 and 300 series 85 litres (22.5 US gallons; 18.7 Imp gallons). Oil capacity 3.5 litres (0.92 US gallon; 0.77 Imp gallon).
Storm 300 Special and Century: One 59.6 kW (79.9 hp) Rotax 912 UL turbocharged four-cylinder four-stroke engine driving a two-blade Rospeller constant-speed metal propeller. Mid-West AE 110 Hawk 78.3 kW (105 hp) rotary engine optional. Fuel capacity of Storm 300 and 300 Special as Storm 280 G; Storm Century 100 litres (26.4 US gallons; 22.0 Imp gallons).
Storm 400 Special: One 119 kW (160 hp) Textron Lycoming o-320 flat-four; engines in the range 82.0 to 119 kW (110 to 160 hp) can be fitted. Fuel capacity 140 litres (37.0 US gallons; 30.8 Imp gallons); optional tanks increase this to 200 litres (52.8 US gallons; 44.0 Imp gallons).
Storm 500 CLK and 500 SLK: One 157 kW (210 hp) Textron Lycoming O-360. Fuel capacity 180 litres (47.6 US gallons; 39.6 Imp gallons); engines in the range 104 to 134 kW (140 to 180 hp) can be fitted.
Storm RG: One 73.5 kW (98.6 hp) Rotax 912 ULS driving a Duc three-blade propeller or one 84.6 kW (113.4 hp) Rotax 914. Fuel capacity as Storm Century.

ACCOMMODATION: Two persons, side by side, with dual controls; single-piece canopy hinged upwards and forwards. Storm 400 TI can accommodate one large or two small additional passengers. Large baggage area behind cockpit.

SYSTEMS: 12 V battery.

AVIONICS: Instrumentation: Option of full IFR fit.