Hi Nigel and Wavewatcher. Thanks for your response. I too was surprised when I first heard of it but there are several operators in Australia who do it. CASA has permitted it, albeit, reluctantly. I know Breeze do not recommend it. I don't know about Goodrich or Air Equip.
The problem came to a head several years ago and there were a series of ADs that addressed the problem. As far as I know, since those ADs have been incorporated, there have been no further problems...but, again, I am more than prepared to be proved wrong. If there is still a problem, then the authorities and manufacturers should do something about it...if there is still a problem.
Again, thanks for the responses so far.