A turbojet fan blade adapted for securement to an engine rotor includes a titanium sheath that extends continuously over its leading edge from blade tip to blade root. The sheath provides impact protection over the leading edge of the blade, and also incorporates enhanced radial securement of the sheath to the rotor. As such, a radial lock system for the sheath is disclosed that includes a fully integrated sheath portion that extends completely over the frontal face of a fan blade dovetail, providing a radial lock of the sheath to the rotor in the event of failure of any adhesive used to attach the sheath to the leading edge. Because the sheath extends continuously from blade tip to the blade root, lightning strike protection is enhanced by avoidance of any discontinuities otherwise associated with related art sheaths that typically extend over only a flow path portion of the leading edge.