How do pilots calculate their rate of descent so that they’re at ground level when the reach the runway?
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1 nautical mile is about 6,000 ft. If you’re in a small plane you do about 90 -200 knots per hour. Per min it’s 1.5 – 3.3knots per minute. If we’re at 18,000 ft and want to descend at a reasonable rate 300 -1000 ft / min. Then we divide our distance by our descent rate to get time in min. A 900fpm descent from a jet highway is reasonable, so we need to start about 20 min out (30-67 nautical miles) we can be at the ground. Usually you have to get in line to land so you aim about 1000 ft above the ground and 1 mile parallel to the runway.
We’ll have a visual check off the wings, so as we pass some big landmark like a lake or a bridge or a dam, or a big freeway we’ll start a descent. If you make the same flight a lot it’s similar to knowing when to merge to the right on the freeway so you’re ready for your exit so you’re not fighting traffic
If you do miss your exit, you can just circle and come down, but if you’re in the clouds and you miss your exit, you fly a route called a missed approach where you hold until atc gives you permission to try again.
Learn to fly. The training is expensive, but the knowledge is all online for free.
Fun fact, airplanes can’t stop, but we have stop signs called holding points, where atc tell us to fly in ovals over a radio signal. The plane has a toll that can see how hard off the signal we are in a game of Marco Polo.
… if you fly with gps you put in your destination and it tells you as you follow a magenta line “TOD” (top of descent). The gps knows how fast you’re going and even if you don’t have a fancy one that is connected to your instruments, you can input your cruising altitude into the flight plan.
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