Retirement in the sun? Time to say goodbye to Dufour's X2.1 prototype

Zurich, June 22, 2023: A curious element of aerospace design is the fate of aircraft prototypes. Prototypes are the incarnation of a flying dream. During development, they are revered and baby-ed – each prototype more sophisticated and refined than the last. ‍

Of course, over time, these prototypes are retired from service, replaced by a new, gleaming version. Some prototypes are cannibalized for parts, and others become objects of national importance. And yes, others retire in the sun, such as a test platform for the Boeing 787 Dreamliner, which retired to an outdoor air and space museum in Arizona. 

Today, Dufour Aerospace retired the second generation Aero2 prototype – called X2.1 – from flight service. During the past two years and hundreds of hover and transition flights, this aircraft has impressively demonstrated its value in the further development of tilt-wing aircraft. The first flights of X2.1 took place at the Raron airfield in Valais, a picturesque part of Switzerland. It later moved for testing at the Dübendorf airfield near Zurich.‍

X2.1 served entirely for aerodynamic testing, for further knowledge during hover and transition and the associated refinement of the models and simulation. The successor model X2.2 will focus more on automated flight and the expansion of flight envelope. Flight test engineers will also focus more on propulsion in order to best prepare for the deployment of the first prototype with hybrid propulsion – called X2.3, of course. Flight tests with X2.2 started about two weeks ago in Dübendorf and the first findings are very promising.‍

Our X2.1 will serve as a static demonstrator for the tilt-wing principle and Dufour Aerospace's tilt-wing aircraft family. And while it won’t fly again – nor will it retire to the sun – it holds a beloved place in the Aero2’s development. 

The 3D on-board video was made on one of the last flights of X2.1 at the Dübendorf airfield: