Captain's and first officers' spheres of influence.

Although the "crew is increasingly the unit of focus for technical and CRM Training, a recent study documented that individual crew members exert influence over the crew in unique ways. The actions of captains and first officers influenced the overall performance of the "crew" both positively and negatively. Captains most often used briefings and leadership behaviors to influence crews. First Officers, on the other hand, influenced crew performance by their use of Inquiry / Assertion / Advocacy, Preparation / Planning / Vigilance activities, and Technical Proficiency.