Question: When was the aircraft that The Silver Falcons fly introduced?

Context paragraphs:
There Was an Old Lady Who Swallowed a Fly: The phrase and title There Was an Old Lady Who Swallowed a Fly—alternatively, "I Know an Old Lady Who Swallowed a Fly," or "There Was an Old Woman Who Swallowed a Fly," or "I Know an Old Woman Who Swallowed a Fly"—is a children's rhyme and song of a kind known as cumulative.  The song tells the story of an old woman who swallowed increasingly large animals, each to catch the previously swallowed animal.  There are many variations of phrasing in the lyrics, especially for the description of swallowing each animal.  The spider and fly are described in each verse, but the other animals are only described when they are introduced starting with the bird.  The absurdity stems from the increasingly improbable solutions that only worsen the initial problem and are more likely to cause the woman's death: the logic of swallowing of even more animals of preposterous sizes without dying, contrasted with the expected, matter-of-fact recounting of her death from swallowing an animal larger than herself, when in fact the swallowing of any animal as a solution was absurd.

Silver Falcons: The Silver Falcons is the aerobatic display team of the South African Air Force.  Based at Air Force Base Langebaanweg near Cape Town, the Silver Falcons fly the Pilatus PC-7 Mk II, the basic trainer of the SA Air Force in a 5-ship routine.  The main purpose of the Silver Falcons is to enhance the image of the South African Air Force, encourage recruitment and instill national pride through public display.

Solar-Powered Aircraft Developments Solar One: The Solar-Powered Aircraft Developments Solar One is a British mid-wing, experimental, manned solar-powered aircraft that was designed by David Williams and produced by Solar-Powered Aircraft Developments under the direction of Freddie To.  It was one of the earliest solar-powered aircraft to fly, after the unmanned AstroFlight Sunrise and the manned Mauro Solar Riser, and on On 19 December 1978 became the first successful British solar-powered aircraft to fly.

Fly, Robin, Fly: "Fly, Robin, Fly" is a song by German disco group Silver Convention from their debut studio album "Save Me" (1975).  Sylvester Levay and Stephan Prager wrote the song, and the latter produced it.  "Fly, Robin, Fly" was released as the third single from "Save Me" in September 1975, peaking at number one on the United States "Billboard" Hot 100.  Thanks to the success of "Fly, Robin, Fly", Silver Convention became the first German act to have a number one song on the American music charts.

Pilatus PC-7: The Pilatus PC-7 Turbo Trainer is a low-wing tandem-seat training aircraft, manufactured by Pilatus Aircraft of Switzerland.  The aircraft is capable of all basic training functions including aerobatics, instrument, tactical and night flying.  It has been selected by more than 20 air forces as their ab initio trainer.  Since the aircraft's introduction in 1978, close to 500 have been sold, with the majority still in service.  Over one million hours have been flown by PC-7s worldwide.

Direct Fly ArGO: The Direct Fly ArGO is a Czech ultralight and light-sport aircraft, designed and produced by Direct Fly sro of Hluk, introduced at the Blois fly-in show in France, in 2011.  The aircraft is supplied complete and ready-to-fly.

Fly Synthesis Syncro: The Fly Synthesis Syncro is an Italian ultralight and light-sport aircraft, designed and produced by Fly Synthesis, introduced at the Aero show held in Friedrichshafen in 2009.  The aircraft is supplied as a complete ready-to-fly-aircraft.

Alexandra (wet fly): The Alexandra wet fly originated in Scotland in the 1860s.  The artificial fly is also known as the Lady of the Lake, the fly was named by English angler Major William Greer Turle to honor Alexandra, Princess of Wales.  The fly is distinguished by the heavy peacock herl wing and silver body which makes the fly resemble a small baitfish or fry.  The Alexandra proved to be a very effective fly for trout in lakes and streams in England and Scotland in the late 19th and early 20th century.  Many fly fishing purists derided the fly and its use was once banned on many English waters.

Rodrig Goliescu: Rodrig Goliescu (1882–1942) was a Romanian inventor, engineer, and Lieutenant, who built the "avioplan", the first airplane with a tubular fuselage. The model, with a length of 1.2 m was successfully tested in 1909, having a take off angle of 30 degrees.  The originality of this aircraft was the shape of the fuselage, designed for minimum drag and acting as a tube fan, similar to the way the modern vertical take off aircraft and helicopters are designed.  This shape reduced drag and increased the efficiency of the propeller.  Helped by the Minister of Education, Spiru Haret, who also helped Aurel Vlaicu, in 1909 he went to France to acquire an engine for his aircraft.  In Paris he sent a survey "Laws of air dynamics" to the French Academy, study that was published in "La France automobile et aérienne" magazine, on 15 May 1909.  Goliescu patented his invention in France (patent no. 402329).  In the same year he learned to fly and he built an updated version of his aircraft, this time in full size.  The aircraft had a half cylinder fuselage, but still the air from the propeller flowed through as in the first model.  He flies with his aircraft for the first time, in November 1909, on Juvisy airfield, near Paris, and he reaches an altitude of about 50 m.  It was for the first time to fly an aircraft with a tubed propeller.

Fly Synthesis Storch: The Fly Synthesis Storch (English: Stork ) is an Italian ultralight aircraft, designed and produced by Fly Synthesis, introduced in 1990.  The aircraft is supplied as a complete ready-to-fly-aircraft or as a kit for amateur construction.

Supporting paragraphs: Silver Falcons Pilatus PC-7
Answer: 1978