Worldwide, weather contributes to one-third of all plane crashes.

Black Box focuses on the investigation teams at two crash sites; the TWA 800 which exploded in mid-flight this summer and the Valujet crash, where cameras follow the team into the alligator-infested swampland. There is also a look at the troubled history of Britain's Comet, the world's first jet passenger aircraft.

The third programme in the series on air disasters examines the deadly effects of tiny flaws in ground maintenance. Examples cited are a Japanese 747 which took over half an hour to fall to earth killing five hundred and twenty passengers in 1985 and a DC10 which crashed whilst trying to land at Sioux City Airport killing one hundred people.

Human error is blamed for two thirds of all air accidents. Look at pilot problems that have resulted in fatal errors of judgment.

The programme investigates real-life cases of airborne terrorism and looks at the work of people charged with solving these cases. Events discussed are the Pacific Southwest Airlines flight which crashed in California on December 7 1987 and the hi-jacking of a Federal Express jet in the United States in 1994. The report also looks at the work of Walter Korsgaard of the bomb investigation section of the Federal Aviation Administration. Since Lockerbie, attempts have been made to make aircraft more resistant to bombs. The film includes footage of tests undertaken at the British Research Defence Establishment at Bruntingthorpe, Leicester.

The programme investigates real-life cases of airborne terrorism and looks at the work of people charged with solving these cases. Events discussed are the Pacific Southwest Airlines flight which crashed in California on December 7 1987 and the hi-jacking of a Federal Express jet in the United States in 1994. The report also looks at the work of Walter Korsgaard of the bomb investigation section of the Federal Aviation Administration. Since Lockerbie, attempts have been made to make aircraft more resistant to bombs. The film includes footage of tests undertaken at the British Research Defence Establishment at Bruntingthorpe, Leicester.