The Sikorsky-Boeing joint helicopter initiative known as the SB-1 Defiant made its first flight last week, gingerly leaving the ground and hovering around the airfield at a Sikorsky facility in West Palm Beach, Florida. This test comes more than 15 months after the helicopter’s competition for the Army’s Future Long Range Assault Aircraft contract, the Bell V-280 Valor, first took to the skies, but Boeing and Sikorsky are confident their aircraft was worth the wait.

“Today’s flight was a tremendous success and a culmination of a lot of work by the men and women of the Sikorsky-Boeing DEFIANT team,” the joint venture announced in a press release. “So much credit goes to their tireless efforts to get us to where we are today.”

The flight lasted around 30 minutes and didn’t include any particularly daring maneuvers, but marked an important developmental step for the prototype aircraft that leans heavily on Sikorsky’s Advancing Blade Concept rotor design. The idea is to use two stacked rotors that spin in opposing directions to produce lift, with a pusher-propeller to add thrust at high speeds. The Defiant prototype that flew last week is only the fourth aircraft Sikorsky has fitted with such a means of propulsion.