There have been plenty of leaksandothersafetyincidents, includingseveral in Japan and aseriousnear-miss at an Americanplantin 2002, butno known bigaccidents resulting in deaths.
The biggest technical challenge Boeing faced in addressing safety concerns raised by the incidents was that there was no quick identification of a root cause.
The Health and Safety Executive said two people died every year in incidents involving ATVs in Britain, but there have been no reported accidents in Wales during the last three years.