Boyd: The Fighter Pilot Who Changed the Art of War by Robert Coram

Boyd: The Fighter Pilot Who Changed the Art of War by Robert Coram cover

High-level summary

John Boyd — also known as 40-second Boyd or Genghis John — was a colonel in the US air force. Early in his career, he developed a theory called "The energy-maneuverability (EM) theory". This theory allowed analysts to calculate (and compare) the maneuverability and combat capabilities of any aircraft.

Using this theory, Boyd uncovered that the US-made F-100 used in Korea was less capable than the Russian-made MiG-21. As you can imagine, air force generals weren't too happy about that.

As a result, they used Boyd's theory to design new aircraft that were superior to those of the Russians, eventually leading to the F-16F-18, and A-10 (all still in use today).

After developing the EM theory, Boyd became interested in the strategic side of conflicts. He wondered why, even though US-made jets were inferior to Russian MiGs, US pilots still frequently beat Korean pilots. If the plane was inferior, how come they still managed to win engagements (in some cases with a 10:1 ratio)? It wasn't just better training.

One of the causes, Boyd thought, was that the US planes had bubble canopies that gave pilots a better view of what was going on around them than their Korean counterparts. Another possible cause was that US planes had hydraulic flight systems, allowing them to transition between maneuvers more rapidly than the MiGs.

Boyd began getting deeper and deeper into the theory of conflict and gave briefings to any general who was willing to listen. His ideas on strategy and maneuverability slowly crystallized in what is now known as the OODA loop (observe-orient-decide-act).

He died of cancer in 1997 at the age of 70. He rarely wrote things down, so his theories and ideas are passed on through the slides and briefings he gave.


  • "A pilot can be too cautious. He can be too methodical. He reads and memorizes the specifications, knows the boundaries of the performance envelope, and is careful never to nudge up against the performance limits. But Boyd did not believe the performance specs and had no fear of the aircraft. He jostled the T-6; he pushed it and horsed it around the sky. He flung the airplane up against the outside edges of the performance envelope and then beyond. If the book said the aircraft should never exceed 260 mph, Boyd pushed it to 265 or 270 or 280. He knew intuitively by the sound of the aircraft when it was approaching not the book limits but the true limits, which, for those bold enough to search for them, always are slightly greater. Test pilots do the same thing, but most of them are engineers and highly skilled pilots tuned to a razor edge of proficiency. Few student pilots are so bold."
  • "There are two kinds of mistakes a student pilot could make when delivering bombs or rockets: “pussy errors” and “tiger errors.” Pussy errors are the result of coming in high, shallow, and slow: the pilot is tentative. Tiger errors are the result of coming in low, steep, and fast: the pilot is overly aggressive. Nobody wanted to be known as the pilot who committed pussy errors."
  • "Upon first learning of Boyd’s early work with E-M, people naturally ask if he had a “target Ps” or an “ideal Ps.” This is not only wrong, it is meaningless. More is usually better in a fighter, but “target” or “ideal” smacks of optimization and Boyd despised optimization. He wanted E-M to explore possibilities across the entire flight envelope."
  • Fun story: "While the denizens of Wright-Pat have always had a very high opinion of themselves, that opinion is not universally shared. A story is told of how a group of former high-ranking German officers was touring military facilities in America and was taken to Wright-Pat. The officers saw the labs and talked with professorial officers and experienced the lofty mustiness of the base, and then one of the German officers turned to his host and quietly said, “Now I know why we lost the war.” His host from Wright-Pat smiled and waited. “We had two bases like this."
  • "Boyd said the outstanding safety records of the European wings showed they were not training hard enough; they were not preparing pilots for combat."
  • "The Air Force simply was going about this the wrong way. As Boyd later explained, “You gotta challenge all assumptions. If you don’t, what is doctrine on day one becomes dogma forever after.""
  • "The chief often followed the Franklin Roosevelt theory of management, bypassing sycophantic generals and seeking out from among relatively junior officers a few men who would tell him the truth."
  • "If your boss demands loyalty, give him integrity. But if he demands integrity, then give him loyalty."
  • "“If you want to understand something, take it to the extremes or examine its opposites,” Boyd said. He practiced what he preached. He considered every word and every idea from every possible angle, then threw it out for discussion, argued endless hours, restructured his line of thought, and threw it out for discussion again. Creativity was painful and laborious and repetitive and detail-haunted—not just to him, but to a half-dozen people around him."
  • "Boyd’s mantra was “Machines don’t fight wars, people do, and they use their minds.” He also preached, “People, ideas, hardware—in that order."
  • "He abhorred guidelines or lists or rules or deductive thinking; everything was intuitive. “You must have inductive thinking,” he said again and again to the Marines. “There is not just one solution to a problem,” he said. “There are two or three or five ways to solve a problem. Never commit to a single solution.""
  • Richards found that a famous observation by Taiichi Ono, the Toyota vice president who created the Toyota system, held true: companies performing reasonably well will not adopt the Toyota system, although they may showcase isolated elements of lean production. Boyd put it more succinctly: You can’t change big bureaucracies until they have a disaster."
  • "Sprey exercised on the A-X perhaps the tightest design discipline that has ever existed on an Air Force project. He worked in a strange confluence of serendipitous forces. Sprey had an iron will and passionate belief about what would make a great CAS airplane, and all those Air Force decision makers who could have gold-plated the airplane had a fervent desire to keep their distance."

Sidenote: One thing that amazed me throughout the book is how many generals wanted to "gold-plate" the new fighter jets. They tried to add a whole bunch of extra systems to the planes so it could do everything. Boyd and his colleague Pierre Sprey vehemently resisted adding unnecessary things and exercises very tight design discipline. It resulted in a couple of exceptional airplanes. The difficulty in building those fighter jets wasn't in adding things, it was keeping overbearing generals at bay.

Funny quotes:

  • "To come in second place is to die, usually in a rather spectacular manner."
  • "But, as one student remembered, “All at once he did a double outside rat’s ass and a two-tone trick fuck and I was a movie star. He had me in his gun camera."
  • "Jokes were made that it was so slow that it suffered bird strikes—from the rear—and that instead of carrying a clock, the cockpit had a calendar."