What happens if air pressure drops suddenly during an IFR flight?

When air pressure drops suddenly during an IFR flight, it primarily affects the accuracy of the altimeter readings. Altimeters are designed to measure air pressure changes in order to determine altitude; therefore, a sudden drop in air pressure can lead to an incorrect indication of altitude. This discrepancy may cause the pilot to be unaware of their actual altitude, potentially leading to dangerous situations such as unintentional descents.

Pilots must be vigilant about monitoring their altimeters and be prepared to make immediate corrections to maintain the desired altitude. This is particularly critical in IFR conditions where flying relies heavily on accurate instrument readings due to limited visibility. Recognizing that air pressure fluctuations can alter altimeter accuracy is essential for safe navigation and maintaining the intended flight profile.