Originally Posted by
Wide Mouth Frog
When you switch a mag off the MAP rises.
I hadn't realised how much of a rise there is. Just found this video where this whole process - both the initial mag check, and the check of the mag switch position and MAP before lifting - is discussed at length, including a demo of the MAP rise on one versus the expected normal figure. He does say that there is hardly any RPM drop during the mag check, and says that means they are healthy. My recollection from FW training is that you want to see a positive drop to confirm you have actually isolated one - not seeing a drop when selecting either L or R would seem to match the fault in the original accident topic.
Smart avionics fit!
For those that know, and can be bothered to watch, why do the rotors start turning after start, with the clutch switch off - residual tension in the belts?
PS. Not much point fitting a four-point harness if it's not worn correctly.......