A substantially autonomous inspection vehicle structured to inspect a turbine disk while said turbine disk is in situ, said turbine disk including an inner hub, a radial planar surface and an outer hub, said inspection vehicle comprising: a body structured to support a plurality of components; a magnetic coupling assembly coupled to said body and structured to movably couple said body to said turbine disk; a motion assembly structured to move said body over said turbine disk; an inspection assembly structured to inspect said turbine disk; wherein said motion assembly includes a plurality of wheel assemblies, a plurality of wheel drive assemblies; characterised in that said motion assembly further includes a plurality of turning assemblies; each said wheel assembly rotatably coupled to said body and having a housing assembly and, a wheel; each turning assembly structured to rotate a wheel assembly relative to said body; each said wheel drive assembly structured to rotate the associated wheel; said body having a leading edge and a trailing edge; said plurality of wheel assemblies includes four wheel assemblies, two wheel assemblies being disposed near said leading edge and two wheel assemblies disposed near said trailing edge; each wheel assembly housing being generally cylindrical, wherein when said body is coupled to said turbine disk, each said wheel assembly housing axis extending generally perpendicularly to the surface of said turbine disk; said plurality of turning assemblies includes two turning assemblies (54A, 54B); each turning assembly (54A, 54B) includes a turning motor having an output shaft, a worm gear, a central gear and an outer gear; each turning assembly outer gear fixed to a wheel assembly housing; one said central gear assembly rotatably coupled to said body and disposed between, and in operational engagement with, each said outer gear on both said leading edge wheel assemblies; the other said central gear assembly rotatably coupled to said body and disposed between, and in operational engagement with, each said outer gear on both said trailing edge wheel assemblies; and whereby said leading edge wheel assemblies turn in conjunction with each other and said trailing edge wheel assemblies turn in conjunction with each other. a body structured to support a plurality of components; a magnetic coupling assembly coupled to said body and structured to movably couple said body to said turbine disk; a motion assembly structured to move said body over said turbine disk; an inspection assembly structured to inspect said turbine disk; wherein said motion assembly includes a plurality of wheel assemblies, a plurality of wheel drive assemblies; characterised in that said motion assembly further includes a plurality of turning assemblies; each said wheel assembly rotatably coupled to said body and having a housing assembly and, a wheel; each turning assembly structured to rotate a wheel assembly relative to said body; each said wheel drive assembly structured to rotate the associated wheel; said body having a leading edge and a trailing edge; said plurality of wheel assemblies includes four wheel assemblies, two wheel assemblies being disposed near said leading edge and two wheel assemblies disposed near said trailing edge; each wheel assembly housing being generally cylindrical, wherein when said body is coupled to said turbine disk, each said wheel assembly housing axis extending generally perpendicularly to the surface of said turbine disk; said plurality of turning assemblies includes two turning assemblies (54A, 54B); each turning assembly (54A, 54B) includes a turning motor having an output shaft, a worm gear, a central gear and an outer gear; each turning assembly outer gear fixed to a wheel assembly housing; one said central gear assembly rotatably coupled to said body and disposed between, and in operational engagement with, each said outer gear on both said leading edge wheel assemblies; the other said central gear assembly rotatably coupled to said body and disposed between, and in operational engagement with, each said outer gear on both said trailing edge wheel assemblies; and whereby said leading edge wheel assemblies turn in conjunction with each other and said trailing edge wheel assemblies turn in conjunction with each other.