If you descend from FL290 to 11,000 without resetting your altimeter, how will it affect your altitude reading?

When descending from a flight level of FL290 to an altitude of 11,000 feet without resetting the altimeter, the reading will depend on the local altimeter setting. The altimeter is calibrated to local atmospheric pressure, and as you alter your altitude, the pressure changes will affect the altitude indicated on the altimeter.

If the altimeter setting is not adjusted to reflect current local barometric pressure, the altimeter may not show the accurate altitude relative to sea level. For example, if the atmospheric pressure is higher than the altimeter is set to, the indicated altitude will be lower than the actual altitude. Conversely, if the atmospheric pressure is low and the altimeter setting hasn't been adjusted accordingly, the indicated altitude may appear higher. Thus, the accuracy of altitude reading directly relates to the correct local altimeter setting at any given time during the descent.

This illustrates why proper altimeter management is crucial in aviation, particularly when transitioning to lower altitudes where pressure changes are more pronounced.