The sixth series of the British medical drama television series Casualty commenced airing in the United Kingdom on BBC One on 6 September 1991 and finished on 27 February 1992.
Geraint Morris returned to the series once more to develop new storylines after actress Brenda Fricker departed in Series 5. In the opening episode, actors Nigel Le Vaillant, Cathy Shipton and Caroline Webster all performed their own stunts in a daring cliff rescue mission high above the Wye Valley.
The series finale "Cascade" centres on an air crash, and was a technical challenge for designer Andrew Purcell. Three different planes, a scale model and a flight simulator were used to capture the action. A static Hawker Siddeley Trident aircraft G-AVFM owned by Brunel University (formerly owned by British Airways) was used for the close up shots which was based at Bristol Airport. A fake embankment was built around the nose and a bridge added to make it appear as if it had crashed into the bank as the aircraft was not allowed to be damaged during filming. The cabin of a Trident class aircraft at RAF Wroughton was used for the interior scenes. A flight simulator at Gatwick was used for the cockpit scenes whilst filming took place inside a light aircraft landing at Bristol Airport and to show the view seen from the cockpit. A scale model of the aircraft was used to show the landing and the moment the crash happens.
As the episode's original air date was the day before the third anniversary of the Lockerbie disaster, the broadcast was postponed until February 1992.
The sixth series of Casualty features a cast of characters working in the emergency department of Holby City Hospital. The series began with 8 roles with star billing. Nigel Le Vaillant appears as specialist registrar and later, emergency medicine consultant Julian Chapman, while Mamta Kaash plays senior house officer Beth Ramanee. Derek Thompson continues his role as charge nurse Charlie Fairhead, and Cathy Shipton stars as sister Lisa "Duffy" Duffin. Patrick Robinson appears as staff nurse Martin "Ash" Ashford, while Ian Bleasdale and Caroline Webster portray paramedics Josh Griffiths and Jane Scott. Robson Green continues to portray porter Jimmy Powell.
Maureen Beattie, Adie Allen, Anne Kristen and Maria Friedman joined the show's main cast as staff nurse Sandra Nicholl, student nurse Kelly Liddle, receptionist Norma Sullivan and social worker Trish Baynes respectively. Allen and Kristen debuted in episode one, Freidman was introduced in episode three and Beattie began appearing in episode eleven. Allen departed the series in episode nine and Friedman left the cast in episode fifteen. Kaash and Green also left the series in episode fifteen.
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