Reprinted with permission of the San Antonio Express-News.

Retired Air Force Reserve Col. Bob Certain had often wondered what path to take in life - others noticed it even when he said little. The slow-motion nudge he got on his final combat mission helped settle the question.

He had long thought of becoming a minister. But busy, focused and never quite ready to commit, Certain put off the decision. But things were beginning to change even before Dec. 18, 1972, when his B-52G was hit by two surface-to-air missiles over Hanoi during the Vietnam War.

On Friday morning, he looked back on that mission, his 100th aboard the fabled Stratofortress, before a crowd at the Missing Man Monument at Joint Base San Antonio-Randolph, saying he was pleased “to be with the men who kept their honor as we lived in the hardships of incarceration in Vietnam.”

Like his future path to the day he would officiate at President Gerald Ford's funeral, Certain's ejection from the bomber seemed to take forever. But it was only a split second before he was tumbling in the night sky under a full moon, enveloped in darkness yet ultimately headed toward the light of his faith.

“I think it was God doing it. I thought it was kind of strange until I started reading the Bible and realizing that it seemed like everybody that God called … they all had arguments with God,” Certain, 70, of San Antonio, said in an interview. “So I wasn't so unique after all, and I think in the Bible it's fairly common for people to sense this call from God and say, 'That can't be happening.'”

He was at Randolph for the 45th annual Freedom Flyer Reunion, which salutes the return of 684 U.S. prisoners from Vietnam in 1973, almost half of them airmen.

Dozens of former Vietnam prisoners of war were on hand to hear Certain, who had made his “champagne” flight a day earlier along with retired Air Force Lt. Col. Hector Acosta, a San Antonio native and St. Mary's University graduate. They sat in the back seats of a pair of T-38 jets that flew over South Texas in a four-plane formation.

The flight, a final, celebratory cap to their aviation careers, ended with Certain and Acosta being sprayed by other freedom flyers with champagne. A third former prisoner, retired Air Force Lt. Col. James W. Williams of Atlanta, got his “fini” flight Friday.

Retired Air Force Col. Harold “Smitty” Harris, 88, of Tupelo, Mississippi, watched with his wife. He recalled learning a long-forgotten 25-letter “tap code” while in survival training and then teaching it to prisoners in Hanoi after he was shot down in his F-105 Thunderchief on April 4, 1965.

The taps started with something like a knock on the door. Five raps on the wall was a call to start a conversation. Two was the response.

“I just happened to be an early shoot-down and showed it to three other guys, and it spread like wildfire,” said Harris, who was jailed in a section of the Hanoi Hilton called “Heartbreak Hotel.”

Certain was 25 when he flew his last mission, and he had flown in combat since 1971 as a B-52 navigator-bombardier. He had been scheduled to fly home from Guam that day but flew 13 hours west instead, his plane carrying more than two dozen bombs destined for a Hanoi rail yard. His return to the U.S. had been delayed by Operation Linebacker II, the “Christmas bombings” that ran from Dec. 18 to 29, 1972, aimed to pressure North Vietnam to end the war.

His Stratofortress, skippered by Col. Donald L. Rissi, closed on the target. The bomb bay doors opened, and Certain, then a captain, had started his stopwatch when a blast rocked the plane. Fire broke out near a tank containing 10,000 gallons of jet fuel. The bombs were released early. Rissi, who also should have been going home, was dying. The B-52's co-pilot, 1st Lt. Robert J. Thomas, and gunner, Master Sgt. Walt Ferguson, also would die.

Certain survived. Things had changed in North Vietnam by the time he arrived in Cu Loc prison, which he and others called “the Zoo.” Like all POWs, he had been trained to foil interrogations, to give worthless information or lie when at the breaking point under torture. Captivity over the years often was brutal, with acts of defiance dealt with harshly.

Related: 4 Vietnam POWs Share Lessons Learned

But their treatment was far better that winter as the war neared its end. Certain said the torture of prisoners stopped after Ho Chi Minh died in 1969. The cabbage and pumpkin soup and the half loaf of French bread in their rations now was supplemented by canned pork, beef and fish from the Soviet Union. Once they even had soybean cookies.

In his cell, Certain did a lot of thinking over his 100 days as a prisoner. He began to lead Sunday services at the urging of other POWs.

It brought Certain closer to the seminary, something he had considered when he was attending church as a teenager twice on Sundays, with a prayer meeting on Wednesday nights. At the time, such a career “felt scary to me, and odd,” and he had backed off, he said. Still, about every other year after that, Certain said, “I would come back to this strong sense that that's what I really ought to be doing and I would struggle against it again - and the last time was the summer of '72.”

Prison simply enabled his choice. But he now knows he was heading there in any case.

“Had I not been a POW, I would have probably chosen to leave the Air Force when my commitment was up and go to seminary after that,” Certain said.

Once freed, the Air Force gave him his pick of assignments, but he had other plans. He entered the seminary and later joined the Air Force Reserve. A parish priest in Episcopal churches across the U.S. and the author of “Unchained Eagle, From Prisoner of War to Prisoner of Christ,” Certain for a time was the rector at Ford's church during the former president's retirement years in California.

They became friends. Certain helped plan and officiate Ford's funeral in Michigan.

One of their more memorable conversations centered over the acquisition of a ladder from the former U.S. Embassy in Saigon, used by those climbing to the building's rooftop, where helicopters evacuated them as South Vietnam's capital fell in 1975. The “Saigon staircase,” as the former president called it in a 1999 speech, was put on display at the Gerald R. Ford Presidential Library.

Ford was president when North Vietnam won the war. His wife, Betty, wondered why he wanted the ladder, Certain said.

“'It's a sign of our failure in Vietnam,'” he recalled her saying. “And President Ford said, 'No, it's a sign of humans striving for freedom.'”