Full scale propulsion tests are under way for the Butterfly programme. Once the results are in, and correlated to real-world data, the team will turn its attention to the full scale prototype.

Bristow continues to add to its future fleet management options with eVTOL aircraft. On top of recent commitments, it has now pre-ordered up to 50 Butterflys for high density, noise sensitive passenger routes.

Butterfly's capability stems from its propulsion system, known as Optimum Speed Propulsion (OSP). The aircraft's four large propellers spin slowly in hover and even slower cruise, resulting in aerodynamic advantages.