Hergé began writing
Flight 714 to Sydney four years after he had ended
The Castafiore Emerald. His enthusiasm for
The Adventures of Tintin had declined, and instead his main interest was
abstract art, both as a painter and a collector. He initially planned on titling his new story
Special Flight for Adelaide before changing it to
Flight 714 to Sydney. While working on the story, Hergé told English translator Michael Turner that "I've fallen out of love with
Tintin. I just can't bear to see him". With
Flight 714 to Sydney, Hergé stated that he wanted a "return to Adventure with a capital A ... without really returning there". He sought to provide answers to two questions: "Are there other inhabited planets? And are there 'insiders' who know it?" Hergé had a longstanding interest in
paranormal phenomena, and believed that a story with such elements would appeal to the growing interest in the subject. He was particularly influenced by
Robert Charroux's
Le Livre des Secrets Trahis ("The Book of Betrayed Secrets"), which expounded the idea that extraterrestrials had influenced humanity during prehistory. The character of Mik Ezdanitoff (Mik Kanrokitoff in the English translation) was based on
Jacques Bergier, a writer on paranormal topics; Bergier was pleased with this. The name "Ezdanitoff" is a pun on "Iz da nie tof", a
Marols (
Brussels dialect) phrase which means "Isn't that great". The television presenter who interviews the protagonists at the end of the story was visually modelled on the
Tintin fan Jean Tauré, who had written to Hergé asking if he could be depicted in the series shaking Haddock's hand. .
Rastapopoulos, a recurring villain in the series who had last appeared in
The Red Sea Sharks, made a return in
Flight 714 to Sydney. In his interviews with
Numa Sadoul, Hergé noted that he was consciously shifting the nature of the villains in the book, relating that "during the story, I realised that when all was said and done Rastapopoulos and Allan were pathetic figures. Yes, I discovered this after giving Rastapopoulos the attire of a
de luxe cowboy; he appeared to me to be so grotesque dressed up in this manner that he ceased to impress me. The villains were debunked: in the end they seem above all ridiculous and wretched. You see, that's how things evolve". Other characters that Hergé brought back for the story were Skut, the Estonian pilot from
The Red Sea Sharks, and
Jolyon Wagg, who is depicted watching television at the very end of the story. Hergé also introduced new characters into the story, such as Laszlo Carreidas, who was based on the French aerospace magnate
Marcel Dassault. In his interview with Sadoul, Hergé also observed that "[w]ith Carreidas, I departed from the concept of good and bad. Carreidas is one of the goodies of the story. It does not matter that he is not an attractive personality. He is a cheat by nature. Look at the discussion between him and Rastapopoulos when, under the influence of the truth serum, they both boast of their worst misdeeds[…] A good example for small children: the rich and respected man, who gives a lot to charity, and the bandit in the same boat! That's not very moral". Hergé also created a secretary for Carreidas in the form of Spalding, whom Hergé remarked off in an interview with
The Sunday Times in 1968 as "an English public school man, obviously the
black sheep of his family". Another character he invented for the story was Dr. Krollspell, whom he later related had "probably 'worked' in a
Nazi camp". He was thus portrayed as a former doctor in one of the Nazi extermination camps—perhaps based partly on
Josef Mengele—who had fled Europe after the
Second World War and settled in
New Delhi, where he established his medical clinic. Although Hergé drew the basis of
Flight 714 to Sydney, his assistants at
Studios Hergé, led by
Bob de Moor, were largely responsible for the story's final look, which included drawing all of the background details and selecting colours. To depict the erupting volcano, Hergé utilised photographs of eruptions at
Etna and
Kilauea that were in his image collection. He also turned to this collection for a photograph of a
flying saucer that he used as the basis for the extraterrestrial spacecraft depicted in the story. Later, Hergé regretted explicitly depicting the alien spacecraft at the end of the story, although was unsure how he could have ended the story without it.
Carreidas 160 '' magazine|alt=A detailed, cross-section design of an aircraft, the Carreidas 160, is shown Hergé wanted the Carreidas 160
supersonic business jet in
Flight 714 to Sydney to have at least the same detailed attention that he had put into all of his fictional vehicles, from the
Unicorn ship in
The Secret of the Unicorn (1943) to the Moon rocket in
Explorers on the Moon (1954). The
faster-than-sound jet aircraft called for by the new
Tintin adventure, while fanciful, could not be viewed as implausible and needed to meet the same exacting standards. Hergé, who had reached his sixtieth birthday and whose drawing hand had begun suffering from
eczema, left the design and drawing of the jet to
Roger Leloup, his younger colleague at Studios Hergé. Leloup, a technical artist and
aviation expert, had drawn the Moon rocket, the
de Havilland Mosquito in
The Red Sea Sharks (1958), and all aircraft in the recently redrawn
The Black Island (1966). Leloup was described by British
Tintin expert
Michael Farr as "the aeronautical expert in the Studios" and his design of the Carreidas 160 as "painstakingly executed and, of course, viable". A "meticulous design of the revolutionary Carreidas 160 jet" was prepared, according to entertainment producer and author
Harry Thompson, "a fully working aircraft with technical plans drawn up by Roger Leloup". Leloup's detailed
cross-sectional design of the Carreidas 160 and its technical specifications were published in a double-page spread for
Tintin magazine in 1966.
Publication Flight 714 to Sydney was serialised in Belgium and France in
Le Journal de Tintin from September 1966. The series was serialised at a rate of one page a week in the magazine. It was then published in collected form by
Casterman in 1968. For this collected version, Hergé had to cut the number of final frames due to a mistake in numbering the pages. Hergé designed the cover for the volume, which Casterman initially thought was too subdued, so he brightened the colours and enlarged the central figures. A launch party for the publication of the book was held in
Paris in May 1968, but was overshadowed by that month's
student demonstrations and civil unrest. When originally published in English by
Methuen that same year, the volume was presented under the shortened title of
Flight 714; since the series' republication by
Egmont Publishing, it has been referred to as
Flight 714 to Sydney, corresponding to the original French title. Among the alterations made to the story by translators Leslie-Lonsdale Cooper and Michael Turner were shifting Carreidas' birth from 1899 to 1906, and changing the location of Krollspell's medical clinic from New Delhi to Cairo. ==Critical analysis==