The Thurston Teal is a family of two- and four-seat all-aluminium amphibious aircraft designed by David Thurston in the United States and first flown in 1968. A total of 38 Teals were manufactured.

Development

David B. Thurston established Thurston Aircraft Corporation at Sanford, Maine, in 1966 to produce a lightweight amphibian of his own design, which had the designation Thurston TSC-1A Teal. First flown in 1968, production began after certification was gained in August 1969; the 16th and subsequent aircraft, which introduced some refinements, were designated TSC-1A1 Teal. In 1972 David Thurston joined the Schweizer Aircraft Corporation, which continued to build the Teal in the form of the TSC-1A2 Teal II before selling the production rights to the Teal Aircraft Corporation of Markham, Ontario, in early 1979. Thurston Aircraft produced a total of 19, Schweizer built 12 and Teal Aircraft constructed seven.

Design

The Teal design features a high wing with tip floats for lateral stability. The horizontally opposed engine is mounted tractor fashion in a strut-supported pylon above the wing root. The T-tail includes a water rudder and tailwheel that swings up against the bottom of the rudder. Conventional undercarriage includes flat, spring-steel main undercarriage legs that rotate aft for water landings. Pilot and passenger sit side by side under a clear perspex canopy. Side windows slide up into opening overhead windows. One unusual characteristic of the Teal design is that it cruises slightly faster with the landing gear in the down position than with it up. The Teal's wheels do not retract, but instead swing to the rear until the gear is horizontal and clear of the water. The drag produced having the landing gear stowed in the up position is higher than in the extended position, and this reduces cruise speed.

Variants

The TSC-1 T-Boat was a proposed flying boat. The aircraft was to have no landing gear to save weight and folding wings were to be incorporated to aid storage. The model development was discontinued to concentrate on the amphibious TSC-1A instead. The TSC-1A was the first to the series to actually be completed and featured retractable conventional landing gear and non-folding wings. The prototype TSC-1A was registered as N1968T, given serial number 1 and was first flown in June 1968. The TSC-1A certified under FAA Type Certificate A15AE on 28 August 1969 at a gross weight of 1850 lb, land and water. An increase in gross weight to 1900 lb was approved on 9 December 1969. Fifteen Model TSC-1A Teals were built by the Thurston Aircraft. The TSC-1A1 Teal Amphibian was an improved model with extra range and payload. The aircraft incorporated 23 US gallon fuel tanks in the wing leading edges, which replaced the single 24.5 US gal fuselage tank of the earlier TSC-1A. The gross weight was increased to 2200 lb (land) and 2100 lb (water). The prototype TSC-1A, N1968T was upgraded and used as the prototype for the TSC-1A1. The TSC-1A1 was certified on 23 September 1971 and Thurston Aircraft built the first three. Three more were built by Schweizer Aircraft. Six additional existing TSC-1As were upgraded to TCS-1A1 status. The TSC-1A1/EW introduced wing and tailplane extensions. Wing span was increased four feet to 34 ft, producing a wing area of 177 sqft. The horizontal tail span was increased by 2 ft to a total of 10 ft. The empty weight rose to 1435 lb, with a gross weight of 2200 lb for both land and water. The TSC-1A1/EW/EP was a project to convert existing TSC-1A1s to TSC-1A1/EW status by incorporating the EW's wing and tail extensions and upgrading the engine to a 160 hp Lycoming O-320-B3B. Gross weight would have been 2300 lb (land) and 2200 lb (water). The TSC-1A2 Teal II was a development of the TSC-1A1, It incorporated slotted flaps, a change in horizontal stabilizer incidence and larger elevator trim tab travel. The fitted engine was a 150 hp Lycoming O-320-A3B. The new flaps reduced stalling speed and thus permitted an increase in gross weight to 2200 lb for land and water operations, as well as shorter take off and landing distances. The TSC-1A2 was certified on 28 June 1973, including IFR in non-icing conditions. Schweizer built nine Teal IIs and seven were built by Teal Aircraft as the "Marlin 150". The TSC-1A2/EP was a proposed upgrade of the TSC-1A2 a 160 hp Lycoming O-320-B3B engine. Empty weight was 1435 lb and the gross weight was to be 2300 lb (land) and 2200 lb (water). The TSC-1A3 was a proposed 180 hp up-engined version of the TSC-1A2. It was developed by Teal Aircraft and was to be sold by the name "Marlin 180" during 1977–78. The Teal III incorporated aerodynamic and structural upgrades to the engine mounting pylon and the engine cowling. The projected empty weight was to be 1450 lb, with a gross weight of 2300 lb (land & water). No TSC-1A3s were manufactured, but TSC-1A2 #34 was converted to 180 hp. The TSC-1A3/EW was a proposed 180 hp engine aircraft with the wings and tailplane extensions of the TSC-1A1/EW. The aircraft was proposed without flaps, but with a gross weight of 2300 lb (land & water). The TSC-1A3/EWF was a proposed aircraft that would have been identical to the TSC-1A3/EW, except with flaps. In 1983 there was a proposal to form a new company, to be called Advanced Aircraft, which would develop a tricycle version of the Teal, to be designated the TSC-1A2T. This was to be a conversion of existing TSC-1A2 aircraft. The conversion would have included: An up-engined version, designated TSC-1A3T, would have been powered by either 160 Lycoming O-320 or Lycoming O-360 180 hp conversion. In the end the company was not formed and the prototype never completed. The TSC-1A4 was a 1977 Teal Aircraft proposal for a four-seat stretched Teal III, which would have had a gross weight of 2700 lb. The plan was for a 210 hp turbocharged Lycoming powerplant, a 19 in extension for the fuselage, the wingspan increased by 4 ft and the tailplane by 2 ft. None were ever built.

Specifications (TSC-1A1 Teal)