zalt / 212. The version of the RFM I posted was current during the Norsk incident - according to the RFM they should have ditched, but (with hindsight) they made a good call and stretched it a few minutes to a platform. The version 212 posts is the revision as a result of that event, indicating that provided there is >5psi, you can continue. A little over 5psi is the sort of pressure you could get with a single pump failure at the time (not sure if it's still the case, I believe there has been some to-ing and fro-ing with check valves since then!)
Its interesting to note the continuing reference to increasing transmission drag in the RFM. I can't help thinking that there is a huge amount of energy going through the transmission - the transmission's job is to pass that whilst converting as little as possible to heat - and if more than a very small amount of that energy is converted into heat (such that you notice the loss of performance), and bearing in mind that heat will be quite localised, surely the metal will melt very quickly, as it does so increasing friction thus the amount of energy converted to heat in a runaway-up kind of way. In other words, surely once you notice you torque for fixed colective is increasing, it would be too late unless you are already in a hover?
HC