Ultrasonic inspection shall b e performed after final heat treatment , but prior to drilling holes, cutting keyways, tapers, grooves, or machining sections t o contour. If the configuration of the forging at the time of inspection is essentially different from type 1 , 2, 3 of attachment 1, the technique sheet issued according to ITN 07084 shall be approved by BHGE and s hall demonstrate the complete coverage of the inspected volume wit hat least two perpendicular angles.