Philip Lamson designed and built the single-seat PL-1 Quark in 1964 as a lighthearted experimental aircraft project to create a prone position-pilot glider. To this end the pilot was accommodated lying down with his head in the nose bubble.

The PL-1 is constructed from fiberglass, with the wings made from a balsa-fiberglass sandwich that was laid up in a female mold. The wing was originally of 20 ft (6.1 m) span, but this was quickly increased to 30 ft (9.1 m) with tip extensions and finally the aircraft received a new 40 ft (12.2 m) three-piece wing. The airfoil was an Irv Culver modification to the NACA 0012. The landing gear was a monowheel, with small wing tip skids.
Soaring Magazine described the aircraft as “purely a lark and a quirky lark at that”. The designer described the performance as “somewhere between a Nimbus and a Rogallo”.

Only one Quark was built and it was registered with the US Federal Aviation Administration in the Experimental – amateur-built category.

The aircraft logged about 300 hours in its 30 ft (9.1 m) wingspan version. The Quark was removed from the FAA registry on 13 August 2002 and the aircraft likely no longer exists.

Length: 10 ft (3.0 m)
Wingspan: 40 ft (12 m)
Wing area: 88.89 sq ft (8.258 sq.m)
Aspect ratio: 18:1
Airfoil: Irv Culver modification to the NACA 0012
Empty weight: 340 lb (154 kg)
Gross weight: 504 lb (229 kg)
Crew: one
Wing loading: 5.67 lb/sq ft (27.7 kg/sq.m)

The XCG-10 is a large military glider capable of accommodating 30 troops or a freight load of 5 short tons. It is a high-wing cantilever monoplane with a deep forward fuselage tapering to a tadpole boom which supports the tail unit. At the break in the bottom lines of the fuselage clam-shell doors give access to the main hold 30 ft.(9.15m) long, 7 ft. (2.14m) wide and 8 ft. 6 in. (2.59m) high, which can accommodate a 155mm howitzer or a 2 1/2 ton truck. Structure is entirely of wood with plywood covering. The wings are fitted with Fowler-type landing flaps and have an overall span of 105 ft. (32m).

The XCG-10 and XCG-10A were two different craft. The 10A was 42 place. Although some sources say the 10 did not exist and the project was changed to 10A in design stage, the 10 was built both as a static test article and a flight test article. The internal hold size was slightly larger for the 10A to accommodate the GM 6X6 truck. The wingspan stayed the same.

Laister-Kauffman XCG-10 / XCG-10A
Crew: 2
Armament: none

In 1938 Jack Laister completed a gull-wing sailplane, which was referred to as the Lawrence Tech Sailplane after its sponsor. Repainted red, white and blue and renamed the ‘Yankee Doodle’ it competed in a 1939 aerobatic competition at the Paris airshow.

With the need for military trainers on the outbreak of World War II, Laister designed the two-place Yankee Doodle 2 from the original that utilized some of the features and technology from the LT-IV but transitioned to a dual cockpit and straight wing arrangement.

A flat-top Version with increased performance also has an ATC. A ‘bunnynose’ LK, flown by Harold Hutchinson, held the national multiplace goal record of 399 km/ 248 miles from 1956 to 1967.

The Vintage Sailplane Association has copies of the military manuals, color scheme drawings and paint chips available.

One LK-10A belongs to the National Soaring Museum.

LT IV
Wing Span: 14.173 m
Wing Area: 12.5 sq m
Structure Weight: 124.7 kg
Flying Weight: 214.3 kg
Wing Loading: 17.14 kg/sq m
Root Chord: 137.2 cm
Tip Chord: 50.8 cm
Aspect Ratio: 16
Fuselage Length: 5.867 m
Stabilizer Span: 269.2 cm

LK-10A
Wing span: 15.2m /50ft
Wing area: 13.33sq.m / 165sq.ft
Empty Weight: 215kg / 475lb
Payload: 181kg / 400lb
Gross Weight: 396kg / 875lb
Wing Load: 29.7kg/sq.m / 5.27lb/sq.ft
L/DMax: 22 89 kph / 45 kt / 55 mph
MinSink: 0.98 m/s / 3.2 fps / 1.90 kt
Aspect ratio: 15.1
Airfoil: NACA 4418, 4409
Seats: 2
No. Built: 156