Problems with Airspeed reading

When downloading and compiling ArduPlane using the instructions here:

Everything seems to function and output just fine, except for the airspeed sensor reading which stays at a constant 63.1. Covering the pitot tube or blowing into it, 63.1. I was asking if there is a way to fix this or if the ardupilot github is causing an issue here.

The airspeed sensor is optional, but recommended. Have you set it up yet via the wiki instructions?