What key information does a primary flight display (PFD) typically provide?

A primary flight display (PFD) is a crucial component in modern aircraft cockpits, designed to present essential flight information to pilots in a consolidated format. The PFD typically provides a wide range of data critical for safe and effective flying, notably including altitude, speed, navigation details, and attitude information.

Altitude is vital for maintaining a safe operating level in relation to terrain and air traffic. Speed information is important for controlling the aircraft’s performance and ensuring it operates within safe limits throughout different phases of flight. Navigation data helps pilots make informed decisions regarding their flight path and aids in adhering to planned routes. Attitude information is essential for understanding the aircraft's orientation in three-dimensional space, allowing pilots to maintain level flight or execute maneuvers appropriately.

While the other options mention various forms of information that can be important for flight safety and operations, they are not the primary focus of what a PFD displays. For instance, while engine performance data and fuel levels are critical, these are typically found on separate displays, emphasizing the PFD's role in presenting flight attitude and navigation essentials directly related to piloting the aircraft. Air traffic information is generally included in other systems, like traffic collision avoidance systems (TCAS), rather than the PFD itself.