In the Bell 212 and Sikorsky 61 we had the Ontrac III (VLF) which promptly went into DR whenever we encountered P static (dry snow).
We also had a good Sperry compass, C-7 as I recall. They didn't usually precess more than about 15 degrees an hour.
We also had ADF's (when the ground station worked) but when you picked up a rig mat or Nodwell or trailer the needles lined up with the load - usually 90 degrees to direction of flight.
The first load in was a ground lighting station with the mercury arc lights pointed straight up.
Next was a trailer that you placed sideways for a good primary radar return. RadAlt was your go to for height.
All this meant we got awfully good at climbing up above the (low) clouds and lookin' at the stars.
I called it the "about yeah" method.
Wind is about "yeah", slow load so ground speed is about "yeah" and drift correction should be about "yeah". That meant Cisco (or Noice or Pat Bay or Cameron) had to be about "yeah". Time to go was calculated with your best guess of groundspeed and your watch.
Plug all the above into the old Mark I brain and give'r!
I will not regal you with stooging around at 300 feet in a 212 pitch dark searching for the ice stations to change tapes (daily) which we did for a month BEFORE we started any of the above.
Weather forecasting, of course, was an FA based on not much.
TC would have us all in jail if we did that stuff now
