Conditions above the studio floor were often dangerous due to the heat and smoke. Although many of the exhaust sound effects used in the series were drawn from an audio library, some were specially recorded during a Red Arrows display at RAF Little Rissington in Gloucestershire. By 1966, Meddings' commitments were split between Series Two and "Thunderbirds Are Go". While Meddings worked on the film, camera operator Jimmy Elliott assumed the responsibility of directing the TV effects. By this stage, the basic frame of "Thunderbird 2" had been damaged so many times that the model had needed to be rebuilt from scratch. Meddings was displeased with the result, reflecting that the replacement was "not only the wrong colour, it was a completely different shape ... I never felt our model-makers managed to recapture the look of the original." Critic David Garland suggests that the challenge facing the "Thunderbirds" effects department was to strike a balance between the "conventional science-fiction imperative of the 'futuristic'" and the "seeping hyper-realist concerns mandated by the Andersons' approach to the puppets". "Thunderbirds" has been praised for the quality of its effects. Jim Sangster and Paul Condon, writers of "Collins Telly Guide", consider the model work "uniformly impressive". To Paul Cornell, Martin Day and Keith Topping, writers of "The Guinness Book of Classic British TV", the effects are "way beyond anything seen on TV previously". Impressed by their work on "Thunderbirds", film director Stanley Kubrick hired several members of Meddings' staff to supervise the effects shooting for "". The series' title sequence, storyboarded by Gerry Anderson, is made up of two parts. It opens with a countdown of "5, 4, 3, 2, 1: "Thunderbirds" Are Go!", provided by Dyneley in character as Jeff Tracy. In a departure from the style of "Stingray", the "Thunderbirds" title sequence varies with each episode: the first part consists of an action montage that serves as a preview of the plot. Simon Archer and Marcus Hearn, biographers of Gerry Anderson, compare this device favourably to a film trailer. The second part, accompanied by composer Barry Gray's "The "Thunderbirds" March", features portraits of the main puppet cast superimposed on various vehicles and settings. Peel describes this as "ostensibly a return to the 'series stars' concept long known in TV", while Garland considers such imagery demonstrative of Anderson's commitment to "incremental realism" through a convergence of human and puppet characteristics.