1. While maintaining a FL of 100 (at 1013.25 hPa), and flying from low pressure to high pressure area, your a/c altimeter will indicate:
a. Lower than FL100
b. Higher than FL100
c. FL100 only
My ANS: C
My understanding to this is that when you are using a constant barometric pressure setting (1013.25 hPa) in the altimeter window, the a/c altimeter will always show the same altitude. The actual a/c altitude may be different depending on whether you are flying from low to high or high to low. In this scenario, you are flying a FL, which means that you have a constant pressure setting in your altimeter, as you pass from one pressure area to another (No changing the altimeter pressure setting).
Hence the term "High to low, look out below" and "Low to high, clear the sky". If you are flying altitudes, you should reset the altimeter setting as you pass to a different pressure area, so that your altimeter will show correct altitude. But if you are flying FL, the altimeter will always show the same FL.
What do you guys think?