iFly GPS Forum

A GPS phone or tablet, unfortunately, is of unknown quality. I know the GPS is accurate, but I have no way of know how good the information presented may be. A possible limitation here is that, while a phone or tablet is getting potentally accurate information, we simply do not know how accurately the bearing on the track made good is being calculated.

At the risk of telling you things you already know, the Earth is an oblate spheriod. Calculating a track on it is not as simple as it might be, although I'd certainly conceed it may be possible to pretend it's flat over short distances, and thus simplify the calculations.

But it's sort of moot. I'm an old man; perhaps mired in older technology, My cell phone has limited capabilities, and so does the tablet I bought a year or so back, that's gathering dust somewhere in the house.

I may someday have a Sky Guard. Right now, I'm broke from 6 years of aircraft building. :)

Thanks for making me think!

Why wouldn't a hiking compass be accurate, or even one from a dime store for that matter? It's just a piece of magnetized steel on a (relatively) frictionless surface. I was under the impression that the only reason an aircraft compass needs to be calibrated is because there's the potential for one or more magnetic fields built into the aircraft (huge steel engine, electrical wiring and associated fields, metal cases around equipment, steel components of the airframe, etc.) to have an effect on the installed compass. So, as long as you took your compass readings while the plane was a suitable distance away, it seems it should work. Of course I'm not an A&P, or anything else that would lend credence to what I've just posted.