Not many I suspect, although I used to use convergency in my head every day in N Alberta.
Just to clarify my comment above, modern technology may well link the VSI to the INS, but there is some confusion because another name for the instantaneous VSI is inertial VSI. This LO is from those written for the EIR which is purported to be for pilots flying non-complex aircraft, typically PPLs. If they really did mean the INS and have not just confused the names, why is it even mentioned?
<fx: mutter, mutter.....>
