That is pretty neat about the engine RPM recorders on stock motors. I wasn't aware.

As for the airspeed sensor, I am refering to airspeed sensors which actually measure TRUE AIRSPEED. The glider guys' sensors are almost certainly dependent upon air density, which complicates things at high altitude. Do you know how the "glider airspeed sensors" work?

I've also seen the airspeed sensors that send a sound pulse from an emitter to a detecter, and backout the airspeed by recording the phase shift or time delay to back out the airspeed. But, as we know, the speed of sound is variant with density as well.

I am speaking of a new sensor that actually measures airspeed, invariant with air density (ie. pressure or temp).