The Alcor, the first pressurized sailplane, was designed by Robert Lamson and first flown in 1973 as a research vehicle able to gain high altitudes while keeping the cockpit environment safe and comfortable. This was achieved by pressurizing the cockpit and building the ship light enough so that it could operate successfully in weak mountain wave conditions. The cockpit pressure differential maintains two to three inches of mercury. The sole Alcor now belongs to the Museum Flight Foundation, Seattle, WA.

Wing span: 20m / 65.6ft
Wing area: 14.31sq.m / 154sq.ft
Empty Weight: 250 kg / 550 lb
Payload: 181 kg / 400 lb
Gross Weight: 431 kg / 950 lb
Wing Load: 30.12 kg/sq.m / 6.16 lb/sq.ft
Aspect ratio: 28
Airfoil: Feifel
L/DMax: 43 89 kph / 48 kt / 55 mph
MinSink: 0.46 m/s / 1.5 fps / 0.89 kt
Seats: 1
No. Built: 1

The LAK-9 Lietuva (or Lithuania) single-seater Open Class sailplane was developed by LAK – Litovskaya Aviatsionnaya Konstruktsiya (or Lithuanian Aircraft Construction) from an earlier plastics sailplane, the BK-7, also named Lietuva, designed by Balis Karvyalis which made its first flight in December 1972. At this time the LAK factory was known as the Experimentalnii Zavod Sportivnoi Aviatsii (or Experimental Sports Aviation Factory), and a small experimental production batch of Lietuvas, designated BK-7A, was built and two of these participated in an international contest between Communist countries at Kishinev in April 1976. As a result of this competition a number of modifications were introduced in a developed version, the LAK-9, designed by Kestutis Gechas and which was then under construction; the prototype of this took part in the World Championships in Finland in June 1976 flown by O.Pasetsnik, but this particular aircraft withdrew from the last two days of the competition because of aileron damage.

The LAK-9 was the first Russian sailplane to compete in the World Championships since 1968 and at the time it was reported that the three LAK-9s then built had not, at that time, completed their flight testing. The type is now in production and the fourth series batch, begun in the winter of 1976-77, is reported to be designated LAK-9M (M for Modernised). The LAK-9 is a cantilever shoulder-wing monoplane of glassfibre/epoxy construction, with single-spar wings and provision of up to 397 lb of water ballast, and trailing edge flaps. The landing gear consists of a retractable monowheel and a tailwheel.

Span: 65 ft 8.25 in
Length: 23 ft 10.25 in
Height: 5 ft 0.25 in
Wing area: 161.35 sqft
Aspect ratio: 26.8
Empty weight: 842 lb
Max weight: 1,477 lb
Max speed: 130 mph (in rough air)
Max aero-tow speed: 87 mph
Min sinking speed: 1.67 ft/sec at 46 mph
Best glide ratio: 48:1 at 64 mph

The plastics BK-7 single-seater Open Class sailplane was developed by LAK – Litovskaya Aviatsionnaya Konstruktsiya (or Lithuanian Aircraft Construction), named Lietuva, designed by Balis Karvyalis, and made its first flight in December 1972. At this time the LAK factory was known as the Experimentalnii Zavod Sportivnoi Aviatsii (or Experimental Sports Aviation Factory), and a small experimental production batch of Lietuvas, designated BK-7A, was built and two of these participated in an international contest between Communist countries at Kishinev in April 1976. As a result of this competition a number of modifications were introduced in a developed version, the LAK-9.