That's a very interesting thought. How would you do it? You can only sense the acceleration - if it's lower than 1G you're falling. The angular momentum doesn't

That's a very interesting thought. How would you do it? You can only sense the acceleration - if it's lower than 1G you're falling. The angular momentum doesn't actually tell you anything in an aircraft. I wonder if it's possible to estimate the local air speed based on ground speed (GPS) and local weather data (can we measure wind speed at altitude?).