Continuing the approach of starting at the nose and working towards the tail, let us now look at functional differences. Unlike the structural differences, functional differences deal mainly with ancillary equipment and features that were easily changed. Functional differences also refer, for the sake of this document, to differences in equipment or systems that allowed the helicopter or a part of the helicopter to function. That said there were considerably more differences here than there were for structural differences.!
Looking at the two variants nose on, it is quickly apparent that the landing lights differed. On the Labrador two fully articulating landing lights were fitted inboard of the chin blisters at the base of the nose. On the Voyageur, the two landing lights were inboard of the chin blisters, but further up on the nose and just below the equipment bay door. The two immoveable lights were placed behind a Plexiglas cover. The Voyageur had but one Labrador style articulating landing light in the same position except that there was no light on the left side. For the three orphans it appears that the three lights remained in use until the aircraft were retired. For the SARCUP Voyageurs the three lights system was replaced with the Labrador style two lights system, both of which were articulating during SARCUP.
Landing lights on the Labrador were also used alternatively as searchlights or hover lights. In 1975, as Voyageurs were integrated into the SAR fleet they received a number of modifications (mods) thought necessary to make the Voyageur even marginally more effective as a SAR resource. I do not believe Labrador type articulating landing lights were included in this series of modifications. Between 1979 and 1983, five Voyageurs (307, 310, 311, 312 and 318) were modified to SARCUP (Search and Rescue Capability Upgrade Program) standard which, among other things, involved removing the Voyageur nose mounted landing lights and incorporating a two light system similar to those on Labradors. Three Voyageurs (308, 315 and 316) were not modified as part of SARCUP and designated “Orphans”. Even after additional modifications through the Voyageur Orphan Follow-up Upgrade Program (VOFUP) started in 1983, these three aircraft retained their Voyageur landing lights. The differences, to the best of my knowledge, endured until retirement.