Abstract: A test unit (412) has an aerial drone (414) which deploys an NDE scanner (416) on a metal surface of the EUT (26) from an aerial drone (414). The test unit (412) has a winch (424) with a winch drive motor (504) and a drive pulley (520) for dispensing and retrieving a deployment tether (418). The winch (424) also includes a reel motor (502) and a reel (496) on which the deployment tether (418) is spooled. The winch drive motor (504) and the reel motor (502) are synchronized to provide a take-up loop (546) formed of the deployment tether (418) which extends between the drive pulley (520) and the reel (496). A take-up arm (512) is connected between the take-up loop (546) and a position sensor (514) for determining the length (544) of the take-up loop (546). The deployment tether (418) is preferably provided by a cogged drive belt.

Abstract: A straight line mechanism with anti-tip features is disclosed having a four bar linkage with two fixed rotation pins and two floating rotation pins. A link extends through the two floating pins and downward beneath the floating pins to define a swing arm. A yoke is mounted in cantilevered arrangement from a lower end of the swing arm by means of two spaced apart offset pins, with the mounting spacing thereof being more closely spaced and at a lower elevation at the swing arm than at the yoke. A probe is pivotally mounted in an end of the yoke disposed opposite of the swing arm, free to rotate in an angular direction about an X-axis disposed transverse to a direction of travel along a Y axis and constrained to travel along the Z-axis, which is preferably perpendicular to the Y-axis.