Boeing has hauled in around 20,000 pounds of potatoes to use as human substitutes during its tests with airplane WiFi. The aircraft maker is checking that onboard wireless signals don't interfere with navigation and communication systems. Groaningly titled SPUDS (Synthetic Personnel Using Dielectric Substitution), the tubers apparently replicate how airborne signals are bounced and absorbed by real-life passengers, but without the need for Boeing to offer complimentary snacks or tiny drinks during testing.