Earlier this year, he told the government he'd be willing to retire sometime this year, and laid out a schedule for his replacement.
That schedule has slipped and slipped and now CBC News has learned the new of the Chief of the Defence Staff, Lt.-Gen. Tom Lawson won't take over until October, at the earliest.
In an exclusive interview with CBC News, conducted aboard a government Challenger jet, Natynczyk talked about his experience in the job and what it demands, inadvertently contrasting his own experience with that of his successor.
Natynczyk had been talking about war and operational experience. He said it is a crucible in which true leadership is forged.
"The level of competence and confidence that comes from that, is extraordinary, and it is army, navy, air force, special forces, it crosses the gamut of the services," he said. "It crosses all the ranks, including to the senior leadership who have all had multiple tours, in different environments, and can, therefore, look at problems and issues back here at home, through the lens of all that operational experience."
Natynczyk said war — or peacekeeping, at least — "changes the nature of who you are, and it changes the threshold of where you actually get excited."
He recounted a story from his own career, when he was posted in 1995 from a peacekeeping command in Bosnia back to Ottawa.
"I was working at National Defence Headquarters and people were dumping these big problems on my desk, and I said, 'Well, you know what? This is easy, because unlike Sarajevo, no one is shooting at me!''
Natynczyk's replacement, Lt.-Gen. Tom Lawson, has none of that peacekeeping or war-fighting experience.
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Lawson's a former fighter pilot who served in Germany during the Cold War, but he wears no ribbons for combat or peacekeeping missions overseas.
Lawson spent the last year as deputy commander of NORAD — the North American air defence agency.
The military's 'mayor'
Natynczyk gave his interview to the CBC in the back of a military Challenger business jet, on the way to Lawson's NORAD headquarters at Peterson Air Force base in Colorado Springs, CO.
There, Natynczyk witnessed Lawson hand his job to a replacement and thanked him for his "extraordinary leadership."
Natynczyk said he is pleased with the quality of the force he's handing over — a force that has grown now to more than 100,000 men and women in uniform: "It's a small city," Natynczyk said. "And I'm the mayor."
"They all sign up voluntarily, God bless them. They all want to make a contribution for peace and security. They all want to make a contribution for Canada. We ask them to do extraordinary things, but like my own kids, you want to protect them."
Natynczyk says his greatest accomplishment was keeping that growing force in fighting shape at a time when it was being asked to do more than at any time in the three decades before.
At one point in 2010, Natynczyk commanded nearly 12,000 troops either on operation, or preparing to go on one. Those missions ranged from Afghanistan to Haiti, from the Olympics, back home, to protecting the G8 and G20 summits.
He has regrets, too. Notably, Natynczyk is disappointed military procurements have become so difficult to manage. This, he says, needs work.
Distressed by toll on soldiers
But the outgoing chief of the defence staff says he is most distressed by DND's inability to properly come to grip with the operational stress and mental health issues that are beginning to seem a plague on the force.
"We've come a long way, but we're not quite there yet with mental health. We're not there at all."
Natynczyk is the second general in a row who was of the new breed of Canadian military leader.
He, and Gen. Rick Hillier before him, motivated soldiers and engaged Canadians through the strength of their character, not just the weight of their gold-embellished epaulettes.
Natynczyk says CDS was a job he never wanted, but he says the imperative of duty, instilled in him since joining the Canadian Forces at the age of 17, compelled him to step up.
"That's what's important. That was in my mind when I said to Rick Hillier, 'Hey listen, I don't want the job. It's a tough job. You got to work hard. But if Canada is asking me to do this, and if this is a call to duty, than I am there for you, and when I am there, I am all in.'"
It was an unusual decision for a man who confesses he would have been happy spending his career as a captain, commanding a troop of tanks.
Although, on this day, Natynczyk seems quite comfortable chitchatting with fellow generals and senior bureaucrats in the back of a private jet, he says he was not, to the manor born.
"I am Walt from Winnipeg, from north-end Winnipeg, from the rough side of the tracks, and I was never born with a silver spoon in my mouth."
And it's to that place, conceptually, at least, that Natynczyk says he's looking forward to returning.
"We've built a little retirement place, and we are looking forward to continuing to work the chainsaws and splitters and chippers out there, 'cause it really is a cleansing kind of time," he said.
"I'm looking forward to being a normal Canadian. I am looking for to being a private citizen, and to just being Walt from Winnipeg, again."