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colechristensenyesterday at 6:37 PM1 replyview on HN

Two ratios dominate aircraft design. Lift/Drag, Thrust/Weight

To get off the ground Lift > Weight, Thrust > Drag, or to simplify to stay aloft Lift = Weight, Thrust = Drag

Bigger engines weigh more.

To get off the ground you need an engine powerful enough to overcome the drag necessary to generate enough lift.

That is what enabled powered flight especially at the beginning. Wing design with a good enough lift to drag ratio and engine+propeller design that had a good enough thrust to drag ratio to come together for more lift than the aircraft weighed.


Replies

chrisweeklyyesterday at 7:02 PM

I was obsessed with fighter jets in my adolescence. My favorite plane was the F-15 Eagle; its thrust:weight ratio was greater than 1 -- meaning it could take off, point its nose straight up to vertical, and keep accelerating past mach 1. Amazing.

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