Use FaceTime with airplane mode on.
As long as my phone is on airplane mode while using FaceTime, does it still connect to my carrier to make the call or does it just use my wifi connection?
iPhone 5
You can't use FaceTime while in airplane mode. FaceTime requires either a WiFi signal, or cellular data. If you turn on Airplane mode THEN turn on WiFi, FaceTime will not use your carrier's data; it will only use WiFi