Which indications are lost with an AHRS/IRS failure?

An AHRS (Attitude and Heading Reference System) or IRS (Inertial Reference System) failure results in the loss of critical information related to the aircraft's orientation in the three-dimensional space. The key parameters affected in such a failure include pitch, roll, and yaw, which are essential for determining the aircraft's attitude.

The AHRS provides real-time data regarding these aspects by integrating data from various sensors to accurately determine the aircraft's orientation relative to the Earth. When the system fails, pilots lose access to this vital information, making it difficult to maintain control and determine the aircraft's position in the sky.

In contrast, the other options pertain to different sets of data that don't directly depend on the functioning of the AHRS or IRS. For example, altitude and vertical speed are derived from altimeters and other sensors, flight path and speed can be determined through airspeed indicators and navigational systems, and turbulence or wind direction measurements are obtained through different atmospheric sensors. Therefore, these aspects remain operational even if the AHRS/IRS experiences a failure.