A triplane is a fixed-wing aircraft equipped with three vertically stacked wing planes. Tailplanes and canard foreplanes are not normally included in this count, although they may be occasionally.
The Zeppelin-Staaken R.VI was a four-engined German biplane strategic bomber of World War I, and the only Riesenflugzeug design built in any quantity.
The Short Admiralty Type 184, often called the Short 225 after the power rating of the engine first fitted, was a British two-seat reconnaissance, bombing and torpedo carrying folding-wing seaplane designed by Horace Short of Short Brothers. It was first flown in 1915 and remained in service until after the armistice in 1918. A Short 184 was the first aircraft to sink a ship using a torpedo, and another was the only British aircraft to take part in the Battle of Jutland.
The Tarrant Tabor was a British triplane bomber designed towards the end of the First World War and was briefly the world's largest aircraft. It crashed, with fatalities, on its first flight.
A Riesenflugzeug, sometimes colloquially referred to in English as an R-plane, was any member of a class of large World War I German bombers, possessing at least three aircraft engines, although usually four or more engines. These were large multi-engine aircraft capable of flying several hours with larger bomb loads than the smaller Grossflugzeug bombers such as the Gotha G.V.
The Roe IV Triplane was an early British aircraft designed by Alliott Verdon Roe and built by A.V. Roe and Company. It was first flown in September 1910.
The Linke-Hofmann R.II was a bomber aircraft designed and built in Germany from 1917.
The Nieuport London was a British night bomber aircraft designed in the First World War. A twin-engined triplane, the London was dogged by the unavailability and unreliability of its engines, and did not fly until 1920. Only two were built.
The Armstrong Whitworth F.K.5 and F.K.6 were experimental triplanes built as escort fighters by Armstrong Whitworth during the First World War. They carried two gunners in nacelles mounted on the centre wing. One example of each type was built, with no further development or production following.
The Sopwith Long Range Tractor Triplane (L.R.T.Tr) was a prototype British long-range three-seat triplane escort fighter of the First World War. Its unusual layout had a small gunner's nacelle mounted on the upper wing for an all-round field of fire. Only a single example was built, as other, smaller fighters proved more practicable.
The Siemens-Schuckert Forssman was a prototype bomber aircraft designed and built in Germany in 1914 and 1915. When its performance proved inadequate for its intended role, even after numerous modifications, the German Inspectorate of Flying Troops eventually accepted it into service as a trainer. Shortly after its acceptance into military service, the aircraft's fuselage fractured while on the ground, ending its career.
The Siemens-Schuckert R.VIII was a bomber aircraft designed and built in Germany from 1916.
The Sopwith Snark was a British prototype fighter aircraft designed and built towards the end of the First World War to replace the RAF's Sopwith Snipes. A single engined triplane, the Snark did not fly until after the end of the war, only three being built.
The Parnall Possum was an experimental triplane, with a single, central engine driving wing-mounted propellers via shafts and gears. Two of these British aircraft were built in the mid-1920s.
The Adolphe Bernard AB was a family twin-engined French biplane aircraft, built near the end of the First World War. Ten AB 1 BN2 bombers were produced for the Armée de l'Air but did not reach squadron service; post-war, two civil derivatives were considered but only one aircraft was built.
The Caproni-Pensuti 2 was a small single-engine sports triplane aircraft designed and built in Italy just before the end of World War I. It had a wingspan of only 4.0 m or a little over 13 ft.
The LVG G.III was a large, twin engine triplane bomber built in Germany near the end of World War I. Only one was completed.
The Schütte-Lanz G.I was a large, twin engine, pusher configuration, experimental biplane built in Germany early in World War I. Only one was completed.
The Dunne-Huntington triplane, sometimes referred to as a biplane, was a pioneer aircraft designed by J. W. Dunne and built by A. K. Huntington. It was of unusual staggered triple-tandem configuration and an early example of an inherently stable aeroplane.
The Caproni Ca.53 was an Italian prototype light bomber built in the last months of World War I.
