The present disclosure relates to a reel holder assembly (1) for an avionics enclosure, the reel holder assembly having a front side, a rear side, an upside and a downside. The avionics enclosure comprises a reel holder (2) comprising at least one channel (21) defined by two ribs (22) for guiding a ribbon cable, the channel (21) extending from the front side to the rear side, wherein each rib comprises first fixing means (25) for engaging with a fibre reel assembly (4). The avionics enclosure further comprises a reel holder foam pad (3) fixed to a downside surface of the reel holder (2), wherein the downside surface can be mounted to the avionics enclosure.