With the prevalence of 802.11 a/b/g/n you will be virtually unable to avoid flying whilst being within receive distance of those wifi frequencies. Given that the frequencies are defined within a specific radio frequency spectrum (see linky), I assume that anything certified for use within an aircraft has gone through anechoic chamber testing of these and any other relevant spectra to ensure little or no interference from such kit.
However, that's not to say that the AP you're considering doesn't suddenly become faulty, etc, etc. In essence, this should in no way be considered as the green light to go do it, but just comment from an informed IT guy who worked for a wifi company and happened to work for another company with an anechoic chamber
http://en.wikipedia.org/wiki/File:2.4_GHz_Wi-Fi_channels_(802.11b,g_WLAN).png