Scimitar

The Scimitar (named vertibird in-game) is a Brotherhood of Steel vertibird

Background
If the Sole Survivor and the Railroad assault Cambridge Police Station and are about to steal Claymore, the Scimitar arrives at the scene with soldiers aboard with the goal of retaking the police station. The Sole Survivor could destroy it and take the Claymore to the Prydwen.

Appearances
The Scimitar appears only in the Fallout 4.