Morane Saulnier L - Franco-British users

The Morane-Saulnier L (AKA Morane-Saulnier MS.3) was a French single or double seater parasol scout airplane. It became one of the first successful fighters when it was fitted with a machine gun and the blades were protected by armoured deflector wedges. It was powered by a single Le-Rhône engine that delivered 80hp of power. It was, however, quickly outdated at the beginning of the World War I.
It made history when flying with the French Aéronautique Militaire as in December 1914 the French Aviator Roland Garros, serving with the Escadrille 23, teamed up with Raymond Saulnier to create a gun synchronizer using a Hotchkiss light machine gun. The first synchronizers fluctuated too much to operate properly so it was chosen to install some deflector metal wedges on the rear surfaces of the propeller blades at the points where they could be hit by one of the bullets. Roland Garros took his armed synchronized type L in March 1915 and scored inmediate success as he managed to shot down three German airplanes in April, a true achievement at the time, specially considering the technological superiority of the German aircrafts during that period. However, on 18th April 1915, Roland Garros was shot down behind the frontlines and the Germans captured him and the airplane before he could burn it.
Around 50 Type Ls served with the British Royal Flying Corps, that were used as scout airplanes in 1915 plus further 25 being used by the Royal Naval Air Service. One of them, flown by Flight Sub-Lieutenant Reginal A.J. Warneford serving with the 1 Squadron RNAS, intercepted the German Army's Zeppelin LZ.37 on 7th June 1915 making it the first Zeppelin to be destroyed in the war and granting Warneford with the Victoria Cross for such achievement.

Sources:
1. https://en.wikipedia.org/wiki/Morane-Saulnier_L
2. Salamander Books - The Complete Book of Fighters