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LAK-12
Role	Open Class sailplaneType of aircraft
National origin	Lithuania
Manufacturer	LAK Sportine Aviacija Sport Aviation USSR
First flight	1986
Status	Production completed
Number built	253

The LAK-12 is a Lithuanian mid-wing, single-seat, FAI Open Class glider that was designed and produced by Lietuviškos Aviacinės Konstrukcijos (LAK) (English: Lithuanian Aircraft Builders) in Lithuania and later by Sportine Aviacija and Sport Aviation USSR.

Design and development

The LAK-12 was designed in the 1980s as an open class racer.

The aircraft is made from fibreglass, foam and carbon fibre. Its 20.42 m (67.0 ft) span foam-core wing employs a Wortmann FX67-K-170 airfoil at the wing root, transitioning to a FX67- K-150 section at the wing tip. The wings feature both double-panel upper surface air brakes and flaps that can be set to -7°, -4°, 0°, +5°, +11° and +15°. Water ballast is 190 L (50 US gal) held in the wing leading edges and dumped through a centre-fuselage valve. The landing gear is a single retractable monowheel suspended by an oil/nitrogen oleo, plus a tailskid. The cockpit canopy is of one-piece and forward hinged.

Operational history

According to Sportine Aviacija, the current type certificate holder, 253 were manufactured over a twenty-five year production run.

In April 2018 there were 17 LAK-12s listed on the United States Federal Aviation Administration registry, all single-place and certified in the Experimental - Racing/Exhibition category and three registered with Transport Canada in the Limited Class.

Variants

LAK-12 Lietuva

20.42 m (67.0 ft) span open-class sailplane.

LAK-12 Lietuva 2R

Two-seat version of the LAK-12 with tandem cockpit in an extended fuselage.

LAK-12E

Experimental 25.5 m (83.7 ft) span variant built in 1988 and tested in 1988 and 1989, incorporating boundary control via blowholes on the lower surface. Only one produced.

Aircraft on display

The sole LAK-12E currently hangs from the ceiling of the Lithuanian Aviation Museum in Kaunas.

Specifications (LAK-12)

Data from Jane's All the World's Aircraft 1988-89

General characteristics

• Crew: one
• Length: 7.23 m (23 ft 9 in)
• Wingspan: 20.42 m (67 ft 0 in)
• Height: 1.92 m (6 ft 4 in)
• Wing area: 14.63 m (157.5 sq ft)
• Aspect ratio: 28.5:1
• Airfoil: Root: Wortmann FX67-K-170, tip: FX67- K-150
• Empty weight: 360 kg (794 lb)
• Max takeoff weight: 650 kg (1,433 lb) with ballast
• Water ballast: 190 L (50 US gal; 42 imp gal)

Performance

• Stall speed: 65 km/h (40 mph, 35 kn)
• Never exceed speed: 250 km/h (160 mph, 130 kn) in smooth air
• Max aero-tow speed: 140 km/h (76 kn; 87 mph)
• g limits: +6 -3
• Maximum glide ratio: 47:1
• Best glide speed: 95 km/h (51 kn; 59 mph)
• Rate of sink: 0.48 m/s (94 ft/min) *Minimum sink speed: 75 km/h (40 kn; 47 mph)
• Wing loading: 44.42 kg/m (9.10 lb/sq ft) max

See also

Aircraft of comparable role, configuration, and era

• Schempp-Hirth Nimbus-2
• ASW-17

Related lists

• List of gliders

References

1. ^ Activate Media (2006). "LAK-12 Sportina Aviacija". Archived from the original on 3 May 2002. Retrieved 26 August 2011.
2. ^ Federal Aviation Administration (10 April 2018). "Make / Model Inquiry Results". Retrieved 10 April 2018.
3. Lednicer, David (2010). "The Incomplete Guide to Airfoil Usage". Archived from the original on 20 April 2010. Retrieved 1 August 2011.
4. "We are". LAK. Retrieved 10 April 2018.
5. Transport Canada (9 May 2017). "Canadian Civil Aircraft Register". Retrieved 9 May 2017.
6. "Sklandytuvas LAK-12E". Lithuanian Aviation Museum. Retrieved 10 April 2018.
7. "Sklandytuvas LAK-12E". Lithuanian Aviation Museum. Retrieved 10 April 2018.
8. John W.R. Taylor, ed. (1988). Jane's All the World's Aircraft 1988-89. London: Jane's Information Group. p. 642. ISBN 0-7106-0867-5.

External links

• 1980s Lithuanian sailplanes
• LAK aircraft
• Glider aircraft
• Aircraft first flown in 1986
• Mid-wing aircraft