Dan Halliday, the creator of Halliday technologies, tightens a strut on a RT3 friction measurement device at Misawa Air Base, Japan, Dec. 7, 2017. This machine is a continuous runway friction tester, meaning the wheel runs nonstop behind the vehicle when driven in a straight line, measuring the surface conditions of the runway. Without the runway friction tester, the 35th OSS would be unable to get calculations of the runway’s surface friction, which is essential to pilots’, ability to depart safely. (U.S. Air Force photo by Airman Xiomara M. Martinez)