The documentary should be this one:
Fatal Logic
At the risk of going off-topic, I mention one more "military aircraft vs cable car" event in addition to Cavalese and the
1961 accident cited by Homsap. It happened in July 1987, when an Italian Air Force M.B.326 severed the traction cable of the Lagazuoi cable car near Cortina d'Ampezzo. There were no fatalities on the cable car and the crew of two on the jet trainer managed to eject safely.