What I learned last week

What I learned last week (#81)

Quote I was thinking about this week:

The enemy of life is middle age.

Orson Welles

Another from Orson that might go with the above:

I started at the top and worked my way down.

Orson Welles

What’s in a winglet:

The idea of turning a wingtip up (or down) dates back to the 19th century. In 1897, English engineer Frederick W. Lanchester patented the placement of end plates vertically at the tip of a wing to control wingtip vortices.

Generally only visible in high moisture conditions, clouds, or fog, vortices appear as twisting ribbons of air behind the wing, almost like mini tornadoes turned sideways. As air flows over the wingtip of a conventional airplane, it tends to roll upward from the high pressure area under the wing to the low-pressure area above it. At speed, airflow over the tip of the wing is also forced backward. This backward flow combines with the upward roll from under the wing to form a vortex.

They may look cool, but they’re a major drag, literally. Vortices cause lift-induced drag, lowering the efficiency of the wing.