What types of displays are integrated into the primary flight displays?

The primary flight displays (PFDs) are critical components of modern aircraft instrumentation and typically integrate essential information needed for flight operations. The correct answer highlights the core functions that a pilot needs to monitor while flying, which include attitude, air data, and navigation information.

Attitude refers to the aircraft's orientation relative to the horizon, which is vital for maintaining controlled flight. Air data encompasses critical elements such as airspeed, altitude, and vertical speed, giving pilots real-time information about the aircraft's performance. Navigation information includes data related to the aircraft’s course, position, and guidance to navigate toward specific waypoints or destinations.

While weather and terrain data, as well as flight planning and scheduling, are important aspects of broader aircraft systems, they do not constitute the primary focus of PFDs. Instead, they are typically displayed on separate screens or systems designed for situational awareness or management. Thus, the integration of attitude, air data, and navigation information into the primary flight displays ensures that pilots have access to the most crucial flight performance metrics in a streamlined and efficient manner.