Flight 21 was a workhorse route, the kind that held together the early American air network. It departed LaGuardia Airport on the evening of February 26, stopped briefly at Washington-Hoover Airport, then pushed south toward Atlanta's Candler Field, with scheduled stops continuing on to New Orleans, Houston, and finally Brownsville, Texas, by morning. Rickenbacker was aboard not as a pilot but as a passenger -- the airline's president traveling his own system. The DC-3, registration NC28394, was the backbone of commercial aviation in 1941, a twin-engine workhorse that had transformed flying from a novelty into a viable business. At 11:38 PM Central Time, the crew radioed Eastern's Atlanta operator to report passing over the Stone Mountain reporting point and beginning descent. The operator transmitted the altimeter setting for Candler Field and the current weather conditions. Everything sounded normal.

Flight 21 contacted the Atlanta control tower twice -- first to announce its approach, then to report its position over the Atlanta range station, two miles southeast of the airport. Eastern's company operator suggested a straight-in approach. The crew acknowledged. Then silence. No distress call, no warning. The DC-3 simply vanished into the dark Georgia night. Investigators from the Civil Aeronautics Board -- the predecessor of today's NTSB -- later pieced together what happened. The aircraft first clipped the tops of three small pine trees while flying northward toward the field, then continued across a shallow valley before the right wingtip caught a poplar. The plane plunged into a thick stand of pines. Rickenbacker testified that he felt a slight bump and leapt from his seat, trying to move toward the rear of the cabin. Then the world came apart. The wreckage was not found until just after 6:30 the next morning, the survivors spending the cold February night trapped among the shattered fuselage and Georgia pines.

The answer to why Flight 21 crashed lay in a dial on the instrument panel. In 1941, air carrier aircraft carried two altimeters: one set to sea-level pressure for en route flight, and one set to the local airport pressure for instrument approaches. After the crash, the approach altimeter read 29.92 inches of mercury -- the standard pressure setting. But the actual altimeter setting at Candler Field that night was 28.94 inches. The difference was almost exactly one inch. That one-inch error translated directly into an altitude error of roughly 1,000 feet, meaning the crew believed they were a thousand feet higher than they actually were. The correct setting had been transmitted to the aircraft and acknowledged by a pilot. Somehow, the altimeter was never properly adjusted. Though investigators acknowledged the instrument could have been disturbed in the crash, the precise one-inch discrepancy matched the altitude error almost exactly. The Civil Aeronautics Board concluded that the crew had failed to set the approach altimeter correctly -- a simple, lethal mistake.

Rickenbacker's injuries from Flight 21 would have killed most men. His skull was dented, his left elbow shattered, the nerve in his left hand crushed and paralyzed. Several ribs were broken. His hip socket was crushed, his pelvis fractured in two places, a nerve in his left hip severed, and his left knee broken. His left eyeball had been expelled from its socket by the force of impact. He spent months in a hospital. Against all expectation, he recovered -- and regained full eyesight. It was not his first miracle. Before the crash, Rickenbacker had already survived a near-fatal case of scarlet fever as a child, a racing car accident, and 26 aerial victories over German pilots in the skies above France during World War I. After the crash, in 1942, his B-17 ditched in the Pacific Ocean and he spent 24 days adrift on a life raft before rescue. Eddie Rickenbacker died in 1973 at age 82, having outlasted seemingly every attempt fate made to claim him.

The crash site in Clayton County, Georgia, is now part of Reynolds Nature Preserve, a quiet expanse of woods and walking trails southeast of what became the busiest airport in the world -- Hartsfield-Jackson Atlanta International Airport, the descendant of the Candler Field that Flight 21 never reached. The accident helped reshape how the aviation industry thought about instrument procedures and altimeter discipline. Today, standardized altimeter setting protocols and cross-checks are drilled into every instrument pilot from the first day of training. The pine grove where eight people died and Eddie Rickenbacker nearly joined them has returned to forest, indistinguishable from the surrounding woodland. But the lesson encoded in that one-inch error on a pressure gauge endures in every cockpit checklist and every call-and-response between pilot and controller: verify the numbers, because the ground does not forgive.