EDITOR’S NOTE: This is Part Two of a three-part series on the search for Spooky 21, an AC-47 gunship that disappeared with its six-man crew while on a secret mission over Laos during the Vietnam War. Reporter Matthew Schofield, who covers defense issues, spent months looking into the story behind the missing plane. He spoke with family members and military officials, and studied records and official histories, as well as traveling to Laos to see how searches were conducted. Part One is running on online and in print on Sunday, May 26, in Issues & Ideas. Part Two and Part Three are running online: http://www.miamiherald.com/issues/

TA-OY, Laos In military lingo, the location of the lost crew of Spooky 21 was a classic SWAG:

Scientific Wild-Ass Guess.

That’s the term investigators use for figuring out something as unpredictable as where a plane should have crashed when it got shot out of the sky.

Guesswork, backed up by some old data, was pretty much all the military had to go on for years in the hunt for the cargo plane-turned-gunship and its crew of six that disappeared over Laos during a Christmas Eve combat mission in 1965.

It wasn’t until 1995, decades after the Vietnam War had ended, that a military team scouring a rice paddy in southeastern Laos found a small amount of wreckage that could have been from the plane. But the crash site was more than 70 miles from where they’d expected to find it.

The Air Force crew that had manned Spooky 21 had long ago been declared dead. But there never had been anything definitive. Without some evidence of the plane or the missing airmen, their families would continue to seesaw between faint hope and heartbreak.

The imprecision of the search made anything definitive a tough mission. In 1999, after several visits to the rice paddy, search teams felt confident enough to call for a full excavation of a site the size of three football fields. Because of red tape, weather and other delays, they didn’t start digging for two more years. Eventually they excavated the rice paddy four times between 2001 and 2011.

Guiding their work was a sacred military trust and the motto of the Joint POW/MIA Accounting Command, known as JPAC, to not stop looking for troops lost on the battlefield “until they are home.”

In the case of Spooky 21, that meant pursuing the fates of men who’d been missing so long they’d now been promoted: Col. Darrell Jeffords, pilot, 40, of Florence, S.C.; Col. Joseph Christiano, navigator, 43, of Rochester, N.Y.; Lt. Col. Dennis L. Eilers, co-pilot, 27, of Cedar Rapids, Iowa; and Chief Master Sgts. William K. Colwell, 44, of Glen Cove, N.Y.; Arden K. Hassenger, 32, of Lebanon, Ore.; and Larry C. Thornton, 33, of Idaho Falls, Idaho.

Such searches were commonplace in Laos. More than 330 U.S. troops disappeared there during the Vietnam War. In its dense jungles and steep hills, even finding a site worth searching was difficult.

In the beginning, the hunt for Spooky 21 relied on villagers who recalled that a large two-propeller plane had crashed in the rice paddy sometime around late 1965. No wreckage was visible, and while telltale evidence doesn’t get up and walk away, the team knew that it can be carried away, piece by piece.

Desperately poor villagers scavenge aircraft wreckage. The metal sheeting becomes a new roof. Beams frame doorways, or are used to lift a hut above the flood zone. Wiring is used to tie walls together. Old bombs are hollowed out and used as water basins.