There now appears to be something in BC that locks out data above some speed. This didn't used to be the case. I often use one or the other of my devices to check location & speed as I fly about, and those tracks show up on the device's memory. They used to show up in Basecamp as well, but haven't for some time -- I don't remember when it changed or what version it was.
Am I imagining things?
I actually enjoy plotting my airline tracks along with the road travel for my various business trips, or used to.