The articale refers to the 8 Chinook Mk 3s that were bought for the Special Forces role. Due to problems with software (amongst others), it was found during evaluation by DERA/QinetiQ that there was a potentially high risk of the flight control system experiencing a runaway. The only way to mitigate this to an acceptable level was to restrict flight in IMC (because this would give less cues to the pilot that a runaway was happening, and would also make the subsequent recovery hazardous) and also restrict cruising flight to greater than 500ft (to give a reasonable margin above the ground for recovery). The media has grabbed hold of this and turned it into "can't fly in the rain", which , of course, sounds utterly ridiculous to the average man/woman in the street. There is currently a program ongoing to convert (or 'revert') the Mk 3s back into a close approximation of the Mk 2 Chinook which has analogue gauges, and does not have the same AFCS architecture that would allow a single software failure to cause an AFCS runaway.