Abstract: Wooden utility pole structures are nondestructively tested while in service, in particular utility pole cross-arms. A helicopter or boom truck brings an operator to the cross-arm. Manually striking the cross-arm using a hammer or other weight with an attached accelerometer senses and sends a shock wave through the cross-arm. The shock wave also is sensed using a second accelerometer sensor in a temporarily affixed sensor pod at the other end of the cross-arm, or alternatively, a non-contact radar vibration sensor is trained on a fastener in the cross-arm, to sense vibration from the shock wave. Practical aspects include mounting particulars for affixing the sensor pod against the cross-arm, manipulating the sensor pod at an elevation below the helicopter working platform, measurements for dimensions and density, etc. The data is received at a processor and correlated with structural strength or used to rank the relative strength of cross-arms.