TYPE: Two seat turboprop powered basic trainer
COUNTRY OF ORIGIN: France
POWERPLANT: One 450kW (600shp) Turboméca Arrius turboprop, derated to 270kW (360shp) driving a three bladed Hartzell propeller.
PERFORMANCE: Max speed at 16,000ft 520km/h (280kt), max cruising speed at 10,000ft 434km/h (234kt), economical cruising speed at 75% power 354km/h (191kt) Max initial rate of climb 2100ft/min. Time to 20,000ft 11 min. Service ceiling 30,000ft. Range at economical cruising speed (75% power) with reserves 1308km (705nm).
WEIGHTS: Empty equipped 860kg (1896lb), average empty equipped with ejection seats 1080kg (2381 Ib), max takeoff 1450kg (3197lb). Dimensions: Wing span 7.92m (26ft Oin), length overall 8.03m (26ft 4in), height 2.64m (8ft 8in). Wing area 9.0m2 (96.88sq ft).
ACCOMMODATION: Seating for two in tandem.
HISTORY: The privately developed Socata TB 31 Omega turboprop trainer has yet to attract a single customer, despite having been available on the world market since the late 1980s.
The TB 31 Omega is a turboprop powered development of Socata's earlier, piston powered TB 30 Epsilon (described in the previous entry). The Omega originally flew as the Turbo Epsilon, which was essentially similar to the Epsilon from the firewall rearwards. The Turbo Epsilon flew for the first time on November 9 1985. Extensive engine development ensued, and the aircraft emerged as the Omega in 1989.
The Omega represents a substantial increase in performance to the Epsilon yet still retains 60% commonality with the earlier trainer. There are several significant and easily identifiable differences though. Most important of the changes is the substitution of the Epsilon's 225kW (500hp) Textron Lycoming AEIO-540 flat six piston engine with a Turboméca Arrius turboshaft. On the Omega the Arrius is flat rated to just 270kW (360shp), down from its original rating of 450kW (600shp) and features Full Authority Digital Electronic Control (FADEC). Power is delivered through a three bladed Hartzell prop, the original Turbo Epsilon featured a composite three bladed Ratier- Fagiec unit. (The Arrius is in use on the Eurocopter AS 555 Fennec/AS 355 Twin Ecureuil.)
Other changes include a new two piece moulded cockpit canopy, which significantly increases all round vision. Underneath the canopy customers can select the optional Martin Baker 15FC lightweight ejection seat, which has a zero height, 111km/h (60kt) speed capability. Changes to the airframe include a revised cowling shape and a dorsal fin. The aircraft avionics features CRT displays for radio and navigation data.
In its definitive form the Omega flew for the first time on April 30 1989. Successful flight testing followed, but Socata was unsuccessful in its attempts to sell the aircraft to the French Air Force, that service instead opting for the much larger, more powerful Embraer Tucano. Nevertheless Socata continues to market the aircraft for export.