Company founded 1990 to provide maintenance and modification services to helicopter operators, and moved into kit and experimental fields to help builders.

Hillberg has also developed the four-seat 1-04, which awaits funding for production. Produces a retrofit kit for the RotorWay Exec, upgrading it to turbine power with a Solar T62-T32 of 112kW and reducing empty weight to 340kg; at least 13 delivered by October 2003.

HILLBERG EH 1-01 ROTERMOUSE and EH 1-02 TANDEMMOUSE

TYPE: Single-seat helicopter kitbuilt; two-seat helicopter kitbuilt.

PROGRAMME: Design and construction of prototype began in August 1990; first flew (N10TE) August 1992. Construction of first production aircraft began in September 1996. Type is currently certified as experimental by FAA.

CURRENT VERSIONS:

• EH 1-01 RoterMouse: Single-seat version. Description applies to EH 1-01 except where indicated.

• EH 1-02 TandemMouse: Tandem two-seat version; under development; was due to fly 1999; this date slipped, but this version is believed to have flown by early 2001. Powered by 112kW Solar T62-T32 turbine engine. Provisional figures appear below.

• EH 1-02A: Development of EH 1-02; has 313kW Rolls-Royce 250-C20B with 681 litre fuel tank.

• CombatMouse: Proposed military version.

CUSTOMERS: By June 2002, 31 had been ordered, of which at least four had been built.

COSTS: Kit: EH 1-01 US$68,000 (2003) ex-works US$100,000; EH 1-02 US$120,000; all prices encompass everything bar radio equipment (2003).

DESIGN FEATURES: Forward fuselage resembles Bell AH-1 HueyCobra. Stub-wing behind cockpit for carriage of external loads. Main rotor speed 510rpm; tail rotor 3,250rpm.

FLYING CONTROLS: Auto-governed hydromechamcal flying controls. Optional rotor brake.

STRUCTURE: Aluminium alloy (2024-T3) monocoque fuselage, bulkheads and keel; stainless steel engine deck and firewall. Rotor has Gyrodyne QH-50 modified blades of NACA 1200 aerofoil section with 8° twist and block tip caps. Modified Robinson R22 hub and transmission. Conventional tail rotor using aluminium-skinned blades.

LANDING GEAR: Fixed steel cross-tube skid type; floats optional.

POWER PLANT: One 108kW Honeywell 36-55-C turboshaft engine driving a non-folding, two-blade, semi-rigid wood-laminated main rotor. Engines in range 108-186kW are suitable. Single 125 litre crash-resistant bladder fuel tank around transmission; refuelling point behind main mast. Optional 76 litre fuel tank on stub-wing. EH 1-02 has 170 litre fuel capacity.

ACCOMMODATION: Single pilot in enclosed cockpit. Entry through upward-hinged port and starboard side windows. Baggage compartment behind seat.

SYSTEMS: 24V 60A electrical system; Electrocraft alternator.

EQUIPMENT: Optional cargo hook.

HILLBERG EH 1-04 Baby Huey

TYPE: Four-seat helicopter kitbuilt.

PROGRAMME: Work is continuing on a proposed development of RoterMouse/TandemMouse with four seats and external cabin styling resembling Bell UH-1 Huey. Max take-off weight 1,134kg.

Jane's All the World's Aircraft, 2004-2005

In addition to helicopter maintenance and modification, Hillberg Helicopters offers the RotorMouse EH 1-01 as a single-seat turbine experimental-category helicopter for construction from a kit (first flown August 1993), RotorMouse EH 1-02 tandem two-seat version, and RotorMouse (Baby Huey) four-seater. Also built the T-4 Turbine as a four-seat turbine helicopter (not in production at time of writing), and produces a retrofit kit for the RotorWay Exec to provide a turbine engine (first flown 1997).

D.Mondey "The New Illustrated Encyclopedia of Aircraft", 2000

Links:

• PRA Rotorcraft Directory

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Technical data for EH 1-01 Main rotor diameter: 6.10m, tail rotor diameter: 0.91m, overall length, rotors turning: 7.32m, fuselage length: 6.35m, height overall: 2.26m, max. take-off weight: 621kg, empty weight: 295kg, max level speed: 257km/h, cruising speed: 209km/h, vertical rate of climb: 823m/min, service ceiling: 4,495m, range with max payload: 555km, range with max fuel: 1287km