Originally Posted by
TorqueStripe
If you're in the States, unless things changed recently, I'm pretty sure the electronic E6B is approved for the written tests.
Not sure about the other models, never used them.
CX2 and CX3 are approved for the written tests in the US. I have a CX2, had it for years. If I was buying new I'd get a CX3. The only thing I've ever used it for is taking the written or making some flight instructor happy. With the advent of things like Foreflight and Garmin Pilot nobody bothers with such primitive flight planning tools anymore!