A genuine question I have always wondered about, (from a fixed wing big-jet pilot):
We have Minimum Safe Altitudes, or Minimum Sector Altitudes, or Minimum En-route Altitudes etc. These are surveyed and published, taking into account the highest ground in a given sector or either side of an airway, for example.
We look on the chart or our PLOG, and take note of the MSA where we are and always fly at least 1000' above that, (or 2000' above it in certain adverse meteorological conditions).
MSA is predicated on the barometric altitude. Do helicopter pilots also operate above minimum safe altitudes, and if so, heli pilots must be used to constantly checking their barometric altimeter, (as well as everything else), during flight ?
When 'scud running'; does a heli pilot deliberately fly below the MSA and hope they can see and stay above the terrain ?