Abstract: A multifunctional labyrinth seal support disk for a turbojet engine rotor is disclosed which also serves to axially lock the rotor blades onto the rotor wheel. A radial support disk has a generally conical, labyrinth seal means extending from the disk in an upstream direction and a conical collar extending from the disk in a downstream direction. The collar has a generally annular bearing surface which bears against an upstream side of the rotor blade roots. Several blade-retaining teeth extend from the collar in a downstream direction and are dimensioned so as to fit within axial grooves between the blade root and the rotor blade wheel. Radially extending spurs bear against the downstream portion of the rotor blade root to axially lock the rotor blade onto the disk. An attaching ring is interposed between the blade retaining teeth and the rotor blade wheel so as to axially lock the multifunctional disk with respect to the rotor blade wheel.