Outside reference in IMC

Bob F. wrote:

For example: It's an attitude indicator, not and artificial horizon.
It's a heading indicator, not a directional gyro.

When and why did the nomenclature on those get changed. I learned to fly
in the late 70's and flew during the early 80's a bunch then laid off
for quite a while and got my helo rating in the mid 90's.

It seemed to have happened sometime before '95 but the helo instructor I
had didn't seem to mind when I called the heading indicator a
directional gyro and there wasn't an attitude indicator in the R22 so it
never came up.

I'll be honest it wasn't until I started building in 2002 that I
realized that everyone was calling them the new names and decided that I
would too.