# Why do some planes seem to be “hovering” while others of the same size/altitude speed through the sky?

805 views
0

I noticed this the other morning and it struck me as fascinating. A bit in the distance was a large commercial plane that seemed to be hanging in mid air. The thing was crawling.
I’ve seen thousands of planes in mid air, but this thing wasn’t far the slowest mover I’d ever seen.

How is it that most planes seem to move at a regular pace while others can seemingly hover through the sky??

In: Physics

Because they are not at the same altitude and speed. You just don’t have a perspective to tell the difference.

I’m not positive and i may be wrong, but i think their larger surface area (bigger wings) help keep it afloat a little easier without needing that extra speed to keep it in the air.

1. It’s hard to tell the speed and distance of things that are 5-8 miles away. They were most likely not at the same height. Things further away will appear to be going much slower like they’re barely moving. Imagine a mountain range on the horizon 21 miles away. Let’s say it takes up 90 degrees of your view, it would be about 30 miles long, If a car was driving across that range at highway speed, it would take 30 minutes. If the mounts were only 10 miles away still taking up 90 degrees of your view, they’d only be 15 miles long. A car driving at highway speed would cross the range in 15 minutes, seeming to be moving twice as fast. If you apply this idea to planes at 25,000 and 40,000 feet they can appear to be moving at very different speeds.

2. Not all planes travel at the same speed. If a flight is getting late and has enough fuel, they’ll sometimes rush the trip a bit. In an attempt to save fuel, aeroplanes travel at only a fraction of their top speed. Cruising speed is generally around 550 mph, but many of the planes can du upward of 800mph.