Abstract: An ultrasonic inspection apparatus operable within a channel associated with a structure is described. The apparatus includes at least one transducer and a holder. The holder includes a material having a flexibility and tensile strength such that a spring force is provided for maintaining a position of said holder within the channel of the structure. The holder includes a plurality of transducer indexing nodes therein for mounting of the transducers, and each node provides a single point of contact between the holder and the transducer. The transducer indexing nodes are fabricated having a material flexibility and tensile strength with respect to a remainder of the holder for positioning of the transducers along surface variances that define the channel.