Which of the following are considered aircraft flight instruments?

The correct answer includes the turn coordinator, heading indicator, and vertical speed indicator as they are all fundamental instruments used in flight operations.

The turn coordinator is an essential flight instrument that indicates the rate of turn, helping pilots maintain a standard rate of turn, which is crucial for safe maneuvering. The heading indicator provides pilots with essential information about the aircraft's current directional heading, which is vital for navigation. The vertical speed indicator is used to show the rate of climb or descent, allowing pilots to maintain desired altitudes during flight and navigate safely through changes in elevation.

In contrast, other combinations either contain one or more instruments not typically classified as primary flight instruments or include instruments that may not be directly relevant to basic flight operations. Understanding these instruments and their functions is critical for pilots to ensure safe and efficient flight operations.