Just back on standby after a week off (which began by having to drive from Inverness to Devon on the Thursday this all started for the UK). Some interesting contributions - Shy, I dunno where you were among the silica sand 30 years ago but I know what it could do to 2 Arrius in the mid-oughties. The Kuwaiti police EC135s had the full sand filtration kit fitted, yet after only 1200-1300 hours of their 3000 TBO the engines had to be replaced as borescope inspections revealed Henry Moore-sculpture shapes where you'd normally expect to see straight lines on the blades. Nasty stuff, dust.