Hawker Siddeley HS 121 Trident (sprva de Havilland D.H.121 in Airco DH 121, Trident - Trizob) je bilo britansko trimotorno reaktivnopotniško letalo, ki je prvič poletelo v zgodnjih 1960ih. Bil je prvo trimotorno reaktivno letalo. Imel je za svoj čas sofisticirano avioniko in je bil prvo potniško letalo, ki je izvedlo avtopristanek.
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