Madrid’s Cuatro Vientos airport (LECU) is some 8 km outside the city. Established in 1911 on a flat plain, the name translates to “four winds”, which is a Spanish expression for an open area. Initially, it was intended for military airships but the first fixed-wing aircraft landed there as early as March 1911.
By 1919, the decision was made to build a signal tower. The basic design was that of a maritime lighthouse, but with the light beam aimed vertically from the top of the tower. It also had a metal wind direction indicator mounted on a ball bearing. The vertical light beam marked the location of the airfield at night and spelt out the airport code in Morse – the letter M (for Madrid). This technique became commonly used at many airports between the 1920s and the late 1940s. Take-off and landing signals were given to the pilots from a large elevated terrace at the bottom of the tower, initially using flags, later replaced by flashing-coloured lights. The room with windows at the bottom of the tower was where the radio operations were installed in the mid-1920s.
The airport developed into a joint civil-military airfield and is still in use today, as an active military base with an operational civil side, mainly accommodating aviation schools. The tower remained in use until 1982 when it was replaced by a more modern control tower on the other side of the airfield. Today, the old tower houses a small museum displaying photographs from that era.