What is the approximate altimeter indication after failing to reset the local barometric pressure of 30.57 after descending from FL250 to a field elevation of 650'?

When descending from a high altitude such as FL250 (which is approximately 25,000 feet) to a field elevation of 650 feet, it is important for the altimeter to be set to the local barometric pressure to reflect the current atmospheric conditions accurately. When the altimeter is not reset to the local setting of 30.57 inches of mercury, it continues to reference the previous setting, which is typically higher due to atmospheric pressure decreasing with altitude.

As the airplane descends, if the altimeter is still reading the original setting, it would indicate a lower altitude than the actual position of the aircraft. Essentially, the aircraft would be higher than what the altimeter suggests if it has not been adjusted. In this scenario, with the original setting and the transition to a much lower altitude, the altimeter would indicate that the aircraft is about 650 feet lower than it truly is. Thus, the altimeter would read approximately 650 feet too low, leading to the correct choice in this situation.