I’m the the US but…I’m pretty sure their calculations only consider you being on a road and will place you at the nearest road you are flying over and think it has a signal error, or just stop working completely flashing signal error. I’d get a cheap handheld multi purpose GPS for that use. My friend spent 150 bucks on one. Thats about a third the cost of a Tom Tom here. Granted you have to input lat / long coordinates into the thing for your airports or navaids. It’ll still provide airspeed, heading etc for you as well as track and eta. Look up the coordinates in the, well its the AFD (airport facility directory) in the US, but I’m sure you have something similar in the UK showing airport details such as runway length, fuel service etc. Put the coordinates into the cheap handheld and label it whatever the desired airport’s ICAO designator is. They work fine. I’ve used them before with no fuss, they’re much cheaper than a car system have memory for normally 99 to 200 waypoints. I’ve used one alongside a Garmin 430 and the readings on both were nearly identical.
The link will take you to the Garmin page that lists all the GPS they carry that work in the air.http://www.garmin.com/aviation/products.…
I’m the the US but…I’m pretty sure their calculations only consider you being on a road and will place you at the nearest road you are flying over and think it has a signal error, or just stop working completely flashing signal error. I’d get a cheap handheld multi purpose GPS for that use. My friend spent 150 bucks on one. Thats about a third the cost of a Tom Tom here. Granted you have to input lat / long coordinates into the thing for your airports or navaids. It’ll still provide airspeed, heading etc for you as well as track and eta. Look up the coordinates in the, well its the AFD (airport facility directory) in the US, but I’m sure you have something similar in the UK showing airport details such as runway length, fuel service etc. Put the coordinates into the cheap handheld and label it whatever the desired airport’s ICAO designator is. They work fine. I’ve used them before with no fuss, they’re much cheaper than a car system have memory for normally 99 to 200 waypoints. I’ve used one alongside a Garmin 430 and the readings on both were nearly identical.