Some software bugs have been linked to disasters . Bugs in code that controlled the Therac-25 radiation therapy machine were directly responsible for patient deaths in the 1980s . In 1996 , the European Space Agency 's US$ 1 billion prototype Ariane 5 rocket had to be destroyed less than a minute after launch due to a bug in the on-board guidance computer program . In June 1994 , a Royal Air Force Chinook helicopter crashed into the Mull of Kintyre , killing 29 . This was initially dismissed as pilot error , but an investigation by '' Computer Weekly '' convinced a House of Lords inquiry that it may have been caused by a software bug in the aircraft 's engine-control computer
crashed
1994 Scotland RAF Chinook crash
Software bug