Can I use a car GPS on a airplane?
Yes, you can use a dedicated GPS device on an airplane. But those multi functional GPS device such as one integrated into an PDA might be prohibited because of the electronic interface with aircraft instruments. I took a Garmin C320 Automotive GPS on an airplane and it recorded a speed of over 700mph, it is also a little bit slow to track and lock satellites when the unit is moving very fast.
The car GPS units typically receive fewer satellites at one time and so are too slow to track – and will keep loosing position. An aircraft certified GPS uses at least 12 channels at a time, and updates at least 1 time per second, and for IFR approaches must at least update 5 times per second. As to whether the car unit will actually work in an airplane – yes. Will the cabin crew allow you to use it – depends. Will it interfere with instrumentation – probably not – but since it’s not an airplane certified unit, it might.
Thor, the straight answer is yes. Depending on which GPS you use your results may vary, HOWEVER, if most of these other “pilots” bothered to actually use their car GPS and they took the time to study it they would most likely find that there is a setting to allow for straightline navigation which takes the road-factor out of play and allows the proccessor to operate more efficiently. Please do your programing of waypoints and such before departure and fly safe!
Allow me to just add to what Nitts has already well answered. Just for fun, I took my car GPS aloft just to see what would happen. It quickly became”lost” and constantly re-adjusted my position. It would not show me on or near any roads and I think that confused it. It also has little provision for altitude changes in extreme like you would find on an aircraft.
