Doolittle's Tokyo Raid has been documented in dozens of books, films and documentaries during the past 60 years.
But the controversy surrounding Plane No. 8, which landed in the Soviet Union, never has been put to rest.
The plane was the only one of 16 B-25s to stray from its orders to fly to China after bombing Japan. Low on fuel, it landed in the Soviet Union, which was closer than China.
Jimmy Doolittle specifically had told the Raiders not to fly to Russia.
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The Soviets held the plane's crew for a year before the airmen finally escaped through what is now Iran. The crew members referred to themselves as "guests of the Kremlin."
Nolan Herndon of Edgefield was navigator, bombardier and gunner.
To this day, Herndon believes that unbeknownst to him at the time, the plane was on a secret mission to test the Soviet Union's resolve as an ally.
Herndon says that pilot Edward "Ski" York, a West Point graduate and the crew's executive officer, along with co-pilot Bob Emmens were under top secret orders that died with the two men after the war.
Herndon first aired his theory in a story in The State last year.
"It's plagued me all through the years," says Herndon, who retired after the war, married the cousin of fellow Raider Sally Crouch and settled in Edgefield. "I don't want people to think we took the easy way out" by not crashing in the North China Sea, as some crews did.
"I think I was hooked into something I didn't know about," Herndon says. "I would have gone anyway. But it's always been a big burr in my side."
Herndon believes that he and the other two junior crew members were kept out of the loop "because two can keep a secret; three can't."
"In thinking it over, it makes me a little heated up to think that I volunteered and risked my life for something I didn't know about," Herndon says.
Other surviving Raiders privately express doubts about the story. Most won't comment.
"I ignore the whole thing," says Maj. Gen. David Jones, one of three squadron commanders at the time and the raid survivors' unofficial leader. "That's him (Herndon). I have no comment whatsoever."
Herndon says that among the unusual occurrences that point to a secret mission are:
-- A 16th plane (his) was added to the mission at the last minute.
-- York and Emmens weren't supposed to go on the mission. Doolittle added them.
-- Herndon and the rest of the fliers assigned to Plane No. 8 had trained with other crews, on other planes.
-- The carburetors of Plane No. 8 carburetors were altered to burn more fuel than the other planes, even though Doolittle had ordered mechanics not to tinker with the planes' engines. The change caused them to run out of fuel earlier. Herndon says that's a convenient cover story.
-- At the time, the United States was trying to persuade the Soviets to allow Americans to use airfields around Vladivostok to bomb Japan.
-- York and Emmens went on to high-level positions in military intelligence.
Carroll V. Glines, the official historian for Doolittle's Tokyo Raiders, says he hasn't been able to find any evidence of a secret side mission. York and Omens, now dead, never talked about the issue.
"I never got a direct answer, and I never pushed it. They were both in intelligence," Glines says. "They were very cautious about anything they said."
Herndon says he never pressed York about it, either.
"I figured if he didn't want to tell me then, he wouldn't tell me later," Herndon says. "I didn't want to cause any hard feelings."
Herndon once asked Doolittle about the flight to the Soviet Union and received a cryptic answer.
The general said, "I'll tell you one thing, Herndon: I didn't send you there."
Glines can't prove Herndon's theory is true, but he can't reject it either.
"Nolan was there, and I wasn't," he says.
Doolittle's Tokyo Raiders formed at the old Columbia Air Base in January 1942, a little more than a month after the Japanese attacked Pearl Harbor, thrusting America into World War II.
Herndon and the other fliers were part of the 17th Bomb Group and 89th Reconnaissance Squadron, four squadrons of B-25 Mitchell bombers stationed in Pendleton, Ore.
They were transferred unexpectedly to Columbia, where the call went out for 25 planes and crews to fly "a dangerous mission overseas."
None of the fliers had any idea their destination would be Tokyo.
"I thought we'd probably go to Europe because we were on the East Coast," Herndon says.
The fliers moved to Eglin Field in Florida to train. The air base at Columbia was too close to the city and too open to prying eyes.
In Florida, the crew underwent exhaustive training, learning to take off on a 500-foot runway at 50 mph, rather than from the typical 5,000-foot runway at 90 mph.
By April, the crews knew they were training for a carrier launch but didn't know the target.
After the men transferred to Alameda Naval Air Station near San Francisco, military officials chose 16 planes and crews for the mission. The planes were loaded onto the aircraft carrier Hornet and strapped to the deck.
The fliers learned two days out to sea that their target would be Japan.
On April 18, 1942, the Soviet Union was at war with Germany but not Japan.
With his military stretched to its limit by the Nazi onslaught, Soviet leader Joseph Stalin did not want to create a second front by declaring war on Japan.
U.S. President Franklin Roosevelt "was pushing to get information on what Russia would do," Herndon says. "We needed their help with Japan. When he saw they didn't shoot us, they knew it would be all right for crippled planes to land there in the future."
The United States had tried to persuade the Soviet Union to let it land its B-17 bombers in Siberia. But the Soviets had moved their best Siberian-based troops to the Western Front to combat the Nazis.
Besides testing Stalin's resolve, the flight to Vladivostok could study airfields U.S. planes might use if the Soviets allowed it, Herndon says.
Using York and Emmens for the secret side mission made sense, Herndon says.
Emmens flew to California on the last day before the Hornet sailed from San Francisco Bay.
Emmens wrote that he and York had asked Doolittle whether they could join the raid.
After the raid, York and Emmens joined military intelligence, two of three Raiders to do so, Glines says.
After World War II, York was an air attache stationed in Warsaw, Poland. He later was chief of staff of the U.S. Air Force Security Service.
According to written histories and the crews' debriefing papers, the difficulties of Plane No. 8 resulted from a lack of fuel caused by faulty carburetion.
In his book "The Doolittle Raid," Glines writes that carburetors on the plane were adjusted against Doolittle's orders, but that was not discovered until the Hornet was well under way from Alameda.
The new carburetors caused the plane to burn 98 gallons an hour, rather than the standard 72 to 75.
Co-pilot Emmens wrote in his book "Guests of the Kremlin" that while in flight, York calculated the amount of fuel the plane carried and decided it could not reach the Chinese mainland - it would come about 300 miles short.
Each plane had new extra tanks, along with a dozen or so five-gallon gas cans in back.
Emmens wrote that he told the pilot, "Ski, if that's right we're not going to get near the Chinese coast."
He wrote that York then shouted, "Have you got the course from Tokyo to Russia plotted, Herndon?"
Herndon says he was too busy at the time to plot a course to the unexpected destination. He was in the nose of the bomber, drawing a bead on his target and looking out for Japanese fighters.
"It seemed like the first thing Ski wanted to do was go to Russia," Herndon says.
Herndon says he replied a little too brusquely to his pilot that "I've got bombs to drop."
"I kind of apologized for saying what I did," Herndon says.
Herndon, in his first combat mission, says he also was busy praying.
"I just kept repeating the 23rd Psalm: 'Lo, though I walk through the Valley of Death, I will fear no evil.' "
Herndon also remembers a sight that lives in his nightmares - a school yard full of Japanese children running from his low-flying aircraft.
The plane dropped its bombs over an industrial area of Tokyo without resistance from enemy fighter planes or anti-aircraft fire. Then it headed north as the other 15 planes headed south and west to China.
Herndon said York flew over several airfields near Vladivostok before a Soviet fighter forced down the plane at a remote airstrip, a sod field Soviet pilots used for practice.
In his debriefings, York gave low fuel as his only reason for flying to the Soviet Union. The debriefing papers also show that York provided a wealth of information on the airfields around Vladivostok.
In the later years of the war, 250 U.S. pilots flying B-17s from Alaska's Aleutian Islands would seek refuge in the Soviet Union.
"They call their reunion group 'Home from Siberia,' " Herndon says. "I guess I'm a charter member."
After Plane No. 8 landed in Vladivostok, the Soviets held its five crewmen in several locations in the Soviet Union.
Limited to the same diet as the besieged Soviet people - mostly black bread and cabbage - the five suffered malnutrition, dysentery and other medical problems.
"I can't blame the Russian people," Herndon says. "They were starving, too. Stalin was the bad guy."
Rather than wait until the end of the war under deplorable conditions, the crew of Plane No. 8 resolved to escape.
While held in Ashkhabad, near the Persian border - thousands of miles from Vladivostok - they found a sympathetic Soviet officer. The man introduced them to an Afghani smuggler who supplied the officers with better food and other black market items.
Crewmen paid the smuggler $250 - the crew members had about $300 in pocket money among them - to lead them to a British embassy in Iran.
The scheme worked. The five, with the help of British diplomats in Mashhad, made their way to India and got a flight home.
Herndon finished the war training navigators for the Army Air Corps, now the Air Force. After the war, he raised cattle in Edgefield, then sold wholesale groceries. He retired about 15 years ago.