Photograph:
Sportine Aviacija Lak 17B FES ZK-GGS (c/n 231) at Nelson Lakes, New Zealand in 2019 (NZCIVAIR)
Country of origin:
Latvia
Description:
Single-seat high-performance glider
Power Plant:
One DC brushless, synchronous permanent magnet electric sustainer motor weighing 7.3 kg (16 lb)
driving a two-blade propeller in the nose.
Specifications:
- Wingspan: 15.00 m (49 ft 2 in)
- Length: 6.53 m (21 ft 5 in)
- Height: 1.29 m (4 ft 3 in)
- Wing area: 9.06 m² (97 sq ft)
- Max speed: 275 km/h (171 mph)
- Max glide ratio: 45
- Rate of sink: 32 m/min (104 ft/min)
- Empty weight: 245 kg (540 lb)
- Loaded weight: 500 kg (1,102 lb)
History:
The LAK 17 series is a single-seat glider designed by members of the Lithuanian Aero Club to meet JAR-22
Utility category regulations. It has a mid-wing with a T-tail, flaps, and a single mainwheel undercarriage. Water ballast
is held in tanks comprising a total of 188 kg (414 lb). It is manufactured by JSC Sportine Aviacija in the Prienal region of
Lithuania. A number of variants have been built, comprising the LAK 17A, LAK 17AT with a Solo 2350 two-cylinder
engine, and the LAK 17A FES with an electric sustainer motor. Development lead to the LAK 17B, LAK 17BT also with the
Solo 2350 engine, and the LAK 17B FES also with an electric sustainer engine.
FES stands for front electric sustainer, the engine being retractable. In the LAK 17B FES, which is an updated variant
of the LAD 17A FES and was first flown in April 2009. The motor drives a two-blade retractable propeller 1 m in
diameter (3.28 ft) in the nose. Power is provided by two battery boxes each weighing 15.5 kg (34 lb). The electric motor
provides 12 to 17 kw (16 to 23 hp) of power at full battery charge and the aircraft can climb at 91 m/min (300 ft/min).
The aircraft can be fitted with a 15 m (49 ft 2 in) or 18 m (59 ft) span wing. In the United States it has a max gross weight
of 600 kg (1,320 lb) and an empty weight of 341 kg (752 lb). With a 91 kg (200 lb) pilot the wing loading is 8.6 lb/sq ft)
and the max wing loading is 11.9 lb/sq ft. A number have been operated overseas in competitions.
A few examples have been imported and operated in this part of the world, two in New Zealand being ZK-GFS (c/n 250) registered
to the Tauranga Gliding Club in July 2019; and ZK-GGS (ex N117SB).