# Method in Action: Wright Brothers and the Lift Tables (1901)

> *This example is part of the [first-principles](../SKILL.md) skill.*

A worked example of first-principles reasoning. Not a pop-figure parable — primary-source documented.

In summer 1901 at Kitty Hawk, Wilbur and Orville Wright tested a new glider built using Otto Lilienthal's published lift coefficients — the authoritative aerodynamics tables of the day. The glider produced roughly **one-third** the lift the tables predicted. Most engineers in that position would have concluded they were applying the tables wrong.

The Wrights did the opposite. They reasoned that the tables themselves might be wrong, because no one had verified them against controlled measurement. Treating "Lilienthal's tables" as **INHERITED**, not as bedrock, they built a six-foot wind tunnel in their bicycle shop in Dayton in October 1901. Over the next several months they tested more than **200 airfoil shapes**, deriving their own lift and drag coefficients from direct measurement.

The result: a corrected Smeaton coefficient (the constant relating air pressure to velocity squared) materially smaller than Lilienthal's value, and new airfoil tables that have survived scrutiny ever since. The 1902 glider, designed using their own measurements, performed as predicted. The 1903 Flyer was built on the same bedrock.

The first-principles move is exact: refuse to treat published authority as bedrock; re-derive the empirical constants from controlled measurement; rebuild the design using only those. The Wrights did not reject Lilienthal — they tore down the inherited *tables*, found the same underlying physics, and got the correct numbers from it. The conventional answer (Lilienthal's lift values) was wrong; the conventional method (controlled measurement of lift) was right. The teardown produces exactly that distinction.

**Sources:** Crouch, Tom D., *The Bishop's Boys: A Life of Wilbur and Orville Wright* (W.W. Norton, 1989); Wright Brothers' notebooks 1901–1902 at the Library of Congress; Smithsonian National Air and Space Museum: https://airandspace.si.edu/explore/stories/wright-brothers-and-invention-aerial-age