The Golden Circle Air T-Bird is a family of

high-wing A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple wings. A monoplane has inherently the highest efficiency and lowest drag of any wing config ...

strut-braced In aeronautics, bracing comprises additional structural members which stiffen the functional airframe to give it rigidity and strength under load. Bracing may be applied both internally and externally, and may take the form of struts, which act in ...

pusher configuration In aeronautical and naval engineering, pusher configuration is the term used to describe a drivetrain of air- or watercraft with propulsion device(s) after the engine(s). This is in contrast to the more conventional tractor configuration, wh ...

ultralight aircraft Ultralight aviation (called microlight aviation in some countries) is the flying of lightweight, 1- or 2-seat fixed-wing aircraft. Some countries differentiate between weight-shift control and Aircraft flight control system, conventional three-a ...

that was produced by

Teratorn Aircraft Teratorn Aircraft, Inc. (named for the Teratornithidae, extinct ice age soaring bird) was an American aircraft manufacturer based in Clear Lake, Iowa. The company specialized in the design and manufacture of ultralight aircraft in the form of ...

Clear Lake, Iowa Clear Lake is a city in Cerro Gordo County, Iowa, United States. The population was 7,687 at the 2020 census. The city is named for the large lake on which it is located. It is the home of a number of marinas, state parks and tourism-related ...

from 1983 to 1989 and then

Golden Circle Air Golden Circle Air, Inc. was an American aircraft manufacturer based in De Soto, Iowa. The company specialized in the manufacture of ultralight aircraft in the form of kits for Homebuilt aircraft, amateur construction and ready-to-fly aircraft u ...

De Soto, Iowa De Soto is a city in Dallas County, Iowa, United States. The population was 915 at the time of the 2020 census. It is part of the Des Moines– West Des Moines Metropolitan Statistical Area. History De Soto got its start in the year 1868, fol ...

from 1989 until the mid-2000s. From 2011-2021 the aircraft were back in production by

Indy Aircraft Indy Aircraft Limited was an American aircraft manufacturer based in Independence, Iowa. The company specialized in the manufacture of ultralight aircraft in the form of kits for amateur construction.Vandermeullen, Richard: ''2011 Kit Aircraft ...

and from 2021 on by

Tbird Aircraft The Ford Thunderbird is a personal luxury car manufactured and marketed by Ford Motor Company for model years 1955 to 2005, with a hiatus from 1998 to 2001. Ultimately gaining a broadly used colloquial nickname, the ''T-Bird'', Ford Introduce ...

. The aircraft is produced as a kit for amateur construction.Johnson, Dan
"T-Bird I and the Future: An Easy-Flying Ultralight,"
May 13, 2008, ByDanJohnson.com (as published in ''Light Sport and Ultralight Flying,'') retrieved June 20, 2023Cliche, Andre: ''Ultralight Aircraft Shopper's Guide'' 8th Edition, page B-60 & B-106. Cybair Limited Publishing, 2001. Teratorn Aircraft: ''1984 Teratorn Tierra II The Legend Continues...'', Teratorn Aircraft pamphlet, 1984.Purdy, Don: ''AeroCrafter - Homebuilt Aircraft Sourcebook'', page 168-169. BAI Communications. Bertrand, Noel; Rene Coulon; et al: ''World Directory of Leisure Aviation 2003-04'', page 142. Pagefast Ltd, Lancaster OK, 2003. ISSN 1368-485XDowney, Julia: ''1999 Kit Aircraft Directory'', Kitplanes, Volume 15, Number 12, December 1998, page 50. Primedia Publications. ISSN 0891-1851Downey, Julia: ''2001 Kit Aircraft Directory'', Kitplanes, Volume 17, Number 12, December 2000, page 54. Kitplanes Acquisition Company. ISSN 0891-1851Downey, Julia: ''2002 Kit Aircraft Directory'', Kitplanes, Volume 18, Number 12, December 2001, page 43. Kitplanes Acquisition Company. ISSN 0891-1851Newby-Gonzalez, Tori: ''2004 Kit Aircraft Directory'', Kitplanes, Volume 20, Number 12, December 2003, page 59. Belvoir Publications. ISSN 0891-1851Downey, Julia: ''2005 Kit Aircraft Directory'', Kitplanes, Volume 21, Number 12, December 2004, page 61. Belvoir Publications. ISSN 0891-1851Vandermeullen, Richard: ''2011 Kit Aircraft Buyer's Guide'', Kitplanes, Volume 28, Number 12, December 2011, page 56. Belvoir Publications. ISSN 0891-1851Bayerl, Robby; Martin Berkemeier; et al: ''World Directory of Leisure Aviation 2011-12'', page 61. WDLA UK, Lancaster UK, 2011. ISSN 1368-485XJohnson, Dan
"Oshkosh 2022 – Day 0… T-Bird is Back; Two-Seat Aerolite; and More As the Show Prepares to Open,"
July 25, 2022, ByDanJohnson.com, retrieved June 20, 2023

Design and development

The original version of the T-Bird family was the Teratorn Tierra which was introduced in 1983. The aircraft achieved early success in the ultralight market, particularly in its

side-by-side seating Tandem, or in tandem, is an arrangement in which two or more animals, machines, or people are lined up one behind another, all facing in the same direction. ''Tandem'' can also be used more generally to refer to any group of persons or objects w ...

version, the Tierra II. The design passed from Teratorn to Golden Circle Air in 1989 and the aircraft was renamed the ''T-Bird''. Golden Circle Air went out of business in the mid-2000s and the design was out of production until 2011, when Indy Aircraft resumed building them. Over 4000 of all models have been built. The T-Bird is constructed from 6061-T6 aluminium tubing, bolted together, with the wing and tail surfaces covered in pre-sewn

Mylar BoPET (biaxially oriented polyethylene terephthalate) is a polyester film made from stretched polyethylene terephthalate (PET) and is used for its high tensile strength, chemical stability, dimensional stability, transparency reflectivity, an ...

-coated

Dacron Polyethylene terephthalate (or poly(ethylene terephthalate), PET, PETE, or the obsolete PETP or PET-P), is the most common thermoplastic polymer resin of the polyester family and is used in fibres for clothing, containers for liquids and foods ...

envelopes. The cockpit area has a

Lexan Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, tough materials, and some grades are optically transparent. They are easily wor ...

windshield and optional zippered cloth doors. The basic versions have

conventional landing gear Conventional landing gear, or tailwheel-type landing gear, is an aircraft Landing gear, undercarriage consisting of two main wheels forward of the Center of gravity of an aircraft, center of gravity and a small wheel or skid to support the tail ...

, with some models offering

tricycle gear Tricycle gear is a type of aircraft undercarriage, or ''landing gear'', that is arranged in a tricycle fashion. The tricycle arrangement has one or more nose wheels in a single front undercarriage and two or more main wheels slightly aft of th ...

as an option; later models can switch quickly between the two configurations. The aircraft is also well-suited to seaplane floats. The cockpit controls consist of conventional rudder pedals and

yoke A yoke is a wooden beam used between a pair of oxen or other animals to enable them to pull together on a load when working in pairs, as oxen usually do; some yokes are fitted to individual animals. There are several types of yoke, used in dif ...

control wheels or (optional) joystick. Construction time for the T-Bird I was reported as 60 hours. The Tierra II introduced a 13-position trim system and also 13-position flaps. The T-Bird I can qualify for the US

FAR 103 Ultralight Vehicles Ultralight aircraft exist outside of the United States. In most countries, ultralights are a class of aircraft. A completely different legal concept is valid within the USA. The FAA makes explicitly clear that ultralight vehicles are not air ...

category if equipped with a light enough engine, such as the

Rotax 277 The Rotax 277 is a , Single-cylinder engine, single-cylinder, two-stroke aircraft engine, that was built by Rotax, BRP-Rotax GmbH & Co. KG of Austria for use in ultralight aircraft.Raisner, William: ''LEAF catalog'', pages 6-105. Leading Edge ...

, although reviewers have indicated that due to the high-drag design the aircraft is under-powered. PilotMix describes the T-Bird I as "the most respected kit in the industry, and for good reason. It is absolutely the strongest and the easiest ultralight to build." Reviewer Andre Cliche calls it "robust...heavy and solid". Reviewer Dan Johnson describes it as slow, but roomy with excellent visibility, "docile," "predictable," rugged, "dependable and enjoyable... with a good reputation," and notes its "excellent rough-field capability."

Variants

;Teratorn Tierra I :Original single seat model that first flew in 1983. ;Teratorn Tierra II :Two seats in

side-by-side configuration Tandem, or in tandem, is an arrangement in which two or more animals, machines, or people are lined up one behind another, all facing in the same direction. ''Tandem'' can also be used more generally to refer to any group of persons or objects w ...

ultralight trainer with a choice of a

Rotax 503 The Rotax 503 is a , inline 2-cylinder, two-stroke engine, two-stroke aircraft engine, built by Rotax, BRP-Rotax GmbH & Co. KG of Austria for use in ultralight aircraft.Raisner, William: ''LEAF catalog'', pp. 6-105. Leading Edge Airfoils, 1 ...

Rotax 532 The Rotax 532 is a two-stroke cycle, two-stroke, two-cylinder, rotary valve engine, liquid-cooled, gear reduction-drive engine that was formerly manufactured by Rotax, BRP-Rotax GmbH & Co. KG. It was designed for use on ultralight aircraft.Ra ...

engine. First flew in 1983. ;Golden Circle Air T-Bird I :Single seat development of the Tierra I with an acceptable power range of , the standard engine is the

. Other engine options include the

Rotax 447 The Rotax 447 is a , inline 2-cylinder, two-stroke aircraft engine, built by BRP-Rotax GmbH & Co. KG of Austria for use in ultralight aircraft.Raisner, William: ''LEAF catalog'', pages 6-105. Leading Edge Airfoils, 1995. Design and developme ...

and

Rotax 582 The Rotax 582 is a two-stroke cycle, two-stroke, two-cylinder, rotary intake valve, oil-in-fuel or oil injection pump, liquid-cooled, gear reduction-drive aircraft engine manufactured by Rotax, BRP-Rotax GmbH & Co. KG. It is for use in non-ce ...

. ;Golden Circle Air T-Bird II :Two seats in side-by-side configuration ultralight trainer, developed from the Tierra II. An acceptable power range of , the standard engine is the

with the

Rotax 912 The Rotax 912 is a horizontally-opposed four-cylinder, naturally-aspirated, four-stroke aircraft engine with a reduction gearbox. It features liquid-cooled cylinder heads and air-cooled cylinders. Originally equipped with carburetors, la ...

optional. Also marketed as the ''T-Bird Side-By-Side''. ;Golden Circle Air T-Bird III :Three seats, with two front seats in side-by-side configuration and one rear seat or optional extended cargo space. The standard engine is the

. Optional equipment includes agricultural spray gear, strut fairings and

tundra tires A tundra tire (UK: ''tundra tyre'') is a large low-pressure tire used on light aircraft to allow operations on rough terrain. A common variant of tundra tire is the bushwheel brand. These tires include an integral inner tube with the valve man ...

. First flown in 1990, 78 were reported flying in 2004. Also marketed as the ''T-Bird Cargo''. ;Golden Circle Air T-Bird Tandem TBT06 :Two seats in

tandem Tandem, or in tandem, is an arrangement in which two or more animals, machines, or people are lined up one behind another, all facing in the same direction. ''Tandem'' can also be used more generally to refer to any group of persons or objects w ...

configuration. The standard engine is the

. Optional equipment includes agricultural spray gear, strut fairings and

. First flew in 1992 and there were 21 reported flying in 1998. Discontinued around 2000. ;Indy Aircraft T-Bird I :Current production single seat model. The standard engine is the

. Construction time 100 hours. ;Indy Aircraft T-Bird II :Current production two seat model. The standard engine is the

. Construction time 140 hours.Tacke, Willi; Marino Boric; et al: ''World Directory of Light Aviation 2015-16'', page 63. Flying Pages Europe SARL, 2015.

Specifications (Tierra II)

References

External links

Official websitePhoto of Golden Circle T-Bird
{{Teratorn Aircraft 1980s United States ultralight aircraft Homebuilt aircraft Single-engined pusher aircraft Teratorn Aircraft aircraft Golden Circle Air aircraft Indy Aircraft aircraft