Abstract: A portable three axis scanner is usable to inspect a gas turbine engine spool in situ upon removing a fan module from the engine. The scanner includes a drive assembly mountable to a forward end of the spool, and a support assembly mountable to an aft end of the spool. A support beam extends between the drive and support assemblies, and a carriage assembly is mounted thereon. The carriage assembly includes a probe support for mounting a removable scanner probe for inspecting the inside of the spool by ultrasonic or eddy current inspection. The drive assembly includes means for axially translating the carriage assembly, means for rotating the carriage assembly, and means for radially translating the probe support and probe thereon so that the probe has three-axis movement including axial, circumferential, and radial, respectively, for being selectively positioned inside the spool between the forward and aft ends thereof for inspecting the spool.