Valmet PIK-23 Towmaster Suhinu (Super-Hinu, "Super Tuggy") is a Finnish two-seat glider tug developed by Polyteknikkojen Ilmailukerho (PIK, Flying club of polytechnic students) in the late 1970s. Like the earlier PIK-15 and PIK-19, the PIK-23 has a secondary but largely unused training role. The PIK-23 is built entirely out of composite materials.
The PIK-23 development began in 1976 when Juha Purje envisaged an improved version of the unsuccessful PIK-19 as his thesis, but the PIK-23 was later redesigned as a completely different type. Valmet wanted to gain experience with composite construction, and in late 1977 Valmet and the Helsinki University of Technology were invited to take part in the project. One of the two prototypes was built at Valmet's factory in Kuorevesi.
The first prototype, OH-TOW, made its first flight on 22 March 1982, piloted by Mikko Järvi, and the second, OH-TUG, in 1983.
Despite intensive marketing efforts, no PIK-23s were ordered. The idea of selling PIK-23s as kits was scrapped, and a proposed four-seat touring version known as the PIK-23B never left the drawing board.
The two PIK-23 prototypes remain in use. OH-TUG crashed fatally in 1991 but was repaired by 1995.
- Crew: 2
- Length: 7.19 m (23 ft 7 in)
- Wingspan: 10.00 m (32 ft 10 in)
- Height: 2.90 m (9 ft 6 in)
- Wing area: 14.00 m2 (150.7 sq ft)
- Aspect ratio: 7.14:1
- Airfoil: NACA 632415 (modified)
- Empty weight: 590 kg (1,301 lb)
- Max takeoff weight: 870 kg (1,918 lb)
- Fuel capacity: 200 L (44 imp gal; 53 US gal)
- Powerplant: 1 × Avco Lycoming O-360-A4M air-cooled flat-four piston engine, 130 kW (180 hp)
- Propeller: 2-bladed Hoffmann, fixed pitch
- Maximum speed: 250 km/h (160 mph, 130 kn) at sea level
- Cruise speed: 220 km/h (140 mph, 120 kn) at 3,660 m (12,010 ft) (65% power)
- Stall speed: 78 km/h (48 mph, 42 kn) (flaps down)
- Never exceed speed: 281 km/h (175 mph, 152 kn)
- Range: 1,250 km (780 mi, 670 nmi) at 3,660 m (12,010 ft) (65% power)
- Endurance: 6 hr 30 min (55% power)
- Rate of climb: 5.80 m/s (1,142 ft/min)
- Takeoff run to 15 m (50 ft): 320 m (1,050 ft)