Metallic lugs are widely used for joining various components of the aircraft frame. During the aircraft operation the fatigue cracks may develop on the ID surface of the lug under the bushing and should be detected through performing of the appropriate inspections regularly. The express detection of the fatigue cracks without disassembly may be performed ultrasonically from the OD surface based on the PAUT modality. For that purpose the PA probe is equipped with the delay line with the specially contoured contact face: the contouring provides optimal matching of the contact face of the delay line with the OD side of the lug along with the slight inclination of the sectorial scan plane towards the side surface of the lug. For the inspection the Sonotron NDT’s ISONIC series PA ultrasonic flaw detectors (ISONIC 3510, ISONIC 2010, ISONIC 2009) should be used. Upon the OD and ID values related to the inspected lug are keyed in the inspection is performed in an extremely simple manner thanks to the true-to-geometry imaging provided.