longer shorter faster

Very recently I had the chance to visit my dear friend and former roommate in Singapore where he now lives with this wife. The flight from San Francisco is one of the longest commercial flights lasting more than seventeen hours from takeoff to landing. The return trip took fewer than fifteen hours. This difference in time is matched by a difference in flight path and can be explained by the affect of the jet stream.

Below is the flight path for United flight 1 on my trip to Singapore. Notice how it’s not a straight line. Straight lines on our maps usually aren’t the shortest distance between two points, a result of the process of “flattening a sphere” to represent the Earth on paper or a screen.

Screen Shot 2017-04-18 at 1.08.50 PM
Actual and planned flight path for UA 001

Nevertheless this route isn’t entirely optimal but it’s close. We never veered too far from land and ended up flying far up north over Alaska.

When we compare it to the return flight, United flight 2, we can see a significantly different route.

Screen Shot 2017-04-18 at 1.07.42 PM
Planned flight path for UA 002

On our return we flew over the deep blue sea and never went much further north than the border between California and Oregon. It’s a longer route but took considerably less time (and fuel). It also took us far away from the safety of land.

Why?

Although I was familiar with how the jet stream can impact a flight I’ve never been able to watch it happen as it happens like I did on my flight home. Having recently discovered that I could watch live wind data from a website I compared the two flights with the air currents at 30,000 to 40,000 ft (thanks to the marvel of in-flight internet access).

You can see that our flight jumped up into the current and sailed along the jet stream over the ocean. With the prevailing winds pushing the plane from behind, the engines were able to be even more efficient and pushed the plane safely faster than they otherwise would have been able to.

Commercial flight is an example of how some systems are complicated and break our intuitions. No engineer or regulator would dare scream to a pilot, “just use common sense!” because common sense doesn’t account for the nuances that make or break a successful journey.

Coincidentally, most important things in life are this way. Because we fail to know that which we do not know we tend to underestimate how difficult or complicated a given task may be. Marriage is this way. Software is this way. Public zoning is this way. Politics is this way. It’s a good reminder not to balk at each other for making decisions that appear at a glance to make no sense.

One thought on “longer shorter faster

  1. Dennis, what an interesting lesson! You are a jewel my friends, and I already knew it since we first met- Thanks for such a wonderful engineer explanation to an interesting phenomenon and for tying it all up to personal relationships.

    Liked by 1 person

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