How Tall Are Those Trees?

By Steve Beste, EAA 652854

You landed at this grass strip yesterday, but this morning the wind has shifted 180 degrees. You’ll be taking off in the other direction. Suddenly, you’re very interested in those tall trees at the end of the runway. Just how tall are they, really?

Or, it’s your home field, and a pilot friend asks how tall the trees are. They used to be 55 feet. But that was some years ago.

Here’s an easy way to measure the height of a tree — or a building or anything else — using just your smartphone.

  1. Download and install an inclinometer app to your phone. There are a lot of them, many free. Just go to your phone’s app store and search on “inclinometer.” I used an app called Inclinometer Free.
  2. Start the inclinometer app and face the tree. Sight along the edge of your phone at the top of the tree. Keeping the top in sight, walk toward the tree until the inclinometer says 45 degrees.
  3. Pace off the distance to the tree. That, plus your height, is the height of the tree.

Here’s the tree line at the end of Runway 04 at my flying club’s home airport, Warrenton Airpark (7VG0) in Warrenton, Virginia. Using this method tells me those trees are 130 feet tall — a lot taller than the standard 50-foot obstacle.

Lead photo by Wikimedia user ТимофейЛееСуда

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