]We had a big vertical card compass that was right in my field of view. The SIRS is much smaller, and it’s so light you can put it anywhere with it’s peel and stick adhesive. Love it.
Compass use story. Somewhat long, ancient news, certainly not backcountry…
You may find it interesting.
JFK-Amsterdam in a Douglas DC-8. About 1/3 across the Atlantic we lost both Inertial Navigation Systems. Pre GPS, so all that’s left is the whiskey compass.
(Unusually, the DC-8 compass is mounted on the cockpit ceiling, aft of the pilots. Each pilot has a movable glare shield mounted mirror, which you angle around to see another mirror on the aft wall of the cockpit, to then see the compass.)
We decided it was safer to go straight ahead. We informed ATC of our condition. Using our dispatch generated flight plan we followed the headings/times. For example, using made up numbers:
50N/40W to 52N/30W
087 degrees for 57 minutes. then
52N/30W to 52N/20W
094 degree for 1 hour 6 minutes
and so on
Finding the UK, we asked the radar controller if they’d been made aware of our situation. “Yes, radar contact, you’re only 10 miles off course, good show”
Words to that effect.
The Inertial Nav system of the day would have had an error tolerance of 3 miles per hour flown, so we beat that.
Traveling the world with 60’s technology was a great time. I’m not being facetious, it was!