The 5 knot tailwind was our ops. I don't think Taca had that restriction. We also had a 10 knot max tailwind for all airports we landed at except San Jose, Costa Rica, which was in the valley at 3,000 feet so one day I landed with a 15 knot tailwind there because the clouds were too low to circle but when I got back to Miami with weather coming in with a 13,000 foot runway at sea level the 15 knot tailwind exceeded our ops. We were the only operation limited so sometimes to try to make things safer it just gets more complicated. Of course the reason they changed to 15 knots at Costa Rica was too many flights couldn't circle because of those typical low clouds so flight were diverting.