A gas turbine engine system comprises a rotor wheel, a plurality of blades, a lockwire and a locking key. The rotor wheel comprises a plurality of axial grooves extending through a periphery of the rotor wheel, and a plurality of posts formed between adjacent slots, each post having a circumferential slot. The blades are mounted in the axial grooves of the rotor wheel, each blade having a circumferential slot circumferentially aligned with the circumferential slots of the posts. The lockwire extends across the plurality of axial grooves of the rotor wheel within each of the circumferential slots of the posts and the blades from a first end to a second end to inhibit axial displacement of the blades within the grooves. The locking key is disposed between the first and second ends of the lockwire and provides support to at least one of the ends of the lockwire to prevent radially inward displacement.