MiG-21 inertial navigation gyro block - video

[metric_taper]

Hang on. What's this now? This sounds super interesting. You can't leave me hanging.

I didn't work in that engineering department, I understood at the time how it worked, but that's now been erased with being retired 10 years. My input into that product was my radiated and conducted RF susceptibility filters. Making products that were not upset with HIRF (High Intensity Radio Frequency) became a real problem when airframes went from all aluminum, to composite. I started work when the BeechCraft Starship airframe was being certified. That's the canard turbo prob design, that was a dud, as it was too heavy and slow. The FAA was very worried about a 'plastic' airframes because of this. Lighting was another huge worry, as that will blast a big hole on entry and exit. So they put in some sort of metal screen as one of the layers of carbon fiber glass.
I wish I could find some link that describes how that AHRS worked.