What might a vertical speed indicator help a pilot assess?

A vertical speed indicator (VSI) is an essential instrument in an aircraft's cockpit that provides the pilot with real-time information about the aircraft's vertical velocity — that is, how quickly it is climbing or descending relative to the Earth's surface. This instrument is critical for understanding the aircraft's flight path and for maintaining safe and controlled flight operations.

When a pilot sees a positive reading on the VSI, it indicates that the aircraft is climbing, while a negative reading indicates a descent. If the VSI shows a zero reading, it signifies that the aircraft is maintaining level flight. This information allows pilots to make informed decisions about altitude adjustments, ensuring compliance with air traffic control instructions, and maintaining safe separation from terrain or other aircraft.

In contrast, the other options do not relate directly to the primary function of the vertical speed indicator. For instance, fuel consumption rates are monitored by different instruments that check fuel flow or gauge levels, while the aircraft's speed is determined using aairspeed indicator—not the VSI. Similarly, weather conditions are assessed through separate navigation instruments and reports rather than the VSI, which focuses solely on vertical motion.