A Question on WiFi and Airplane Mode

This might be a dumb question but here it goes. How do I know the wifi works on my phone. Here's my problem: when in Airplane Mode with the wifi on and connected to my home network if I try to load a page in Safari it goes gray with the spinning gear telling me its trying to connect. If I'm standing if front of my Airport Extreme Base Station there is no lights signaling a transmission. (BTW, the AE is fine works with three other Macs in the house.) If I take the iPhone out of Airplane Mode and have the wifi on the page in Safari loads fine. In fact I can see the light blinking on the AE indicated its transmitting. So I'm puzzled here. Does the WiFi not work at all in Airplane Mode regardless if the wifi is on? Would this be a hardware or software issue. I tried the network reset on the phone but have had no luck in changing this situation. I don't know if this matters but where I live (southern Indiana) there is no 3G service so that's off on the phone. The phone connects with AT&T strictly on EDGE. Any ideas would be welcome.