This used corrugated light alloy skin panels, and made for easy maintenance and inspection.

The prototype, which differed from the standard Wibault 7 by having a new undercarriage and British instruments, was delivered to Britain in February 1926[2] and was later fitted by Vickers with strengthened wing struts.

[3] The first Vickers built Type 121 flew at the end of June 1926, but crashed following an inverted spin on its first flight.

This was found to be due to problems with the aircraft's centre of gravity, which were resolved by modifying the tailplane.

[4] The first Type 121s were delivered to Chile in November 1926, partly equipping the Groupo Mixto de Aviación 1, with deliveries continuing until October 1927.