Wop May, Vic Horner, and the Mercy Flight to Fort Vermilion

On January 2, 1929, pilots Wilfrid “Wop” May and mechanic Vic Horner departed Blatchford Field in Edmonton, Alberta carrying diphtheria antitoxin to Fort Vermilion - a community roughly 700 miles north facing a deadly outbreak with no other hope of timely medical supply. Flying in temperatures around -30°F, they completed the journey in under two days. The dogsled alternative would have taken a minimum of three weeks.

Who Was Wop May?

Born in Manitoba in 1896 and raised in Edmonton, Wilfrid Reid May earned the nickname “Wop” in childhood and never shed it. He was restless, calculating, and exactly the kind of person who eventually finds his way into a cockpit.

He joined the Royal Flying Corps, trained in England, and shipped out to the Western Front at twenty-one. His first combat mission was April 21, 1918.

The Day the Red Baron Died

That date matters. On the same afternoon May flew his first combat sortie over the Somme Valley, Manfred von Richthofen - the Red Baron, 80 aerial kills to his name - came out of the sun behind May’s Sopwith Camel. A green pilot on his first mission was exactly the kind of target von Richthofen dispatched routinely.

Roy Brown, May’s squadron leader, dove in to break the attack. Australian ground troops below opened fire simultaneously. Von Richthofen went down near the Somme. The British credited Brown; the Australians have argued for their ground fire ever since. The debate has run for over a hundred years. What is not disputed: May flew home.

He flew more than 100 additional missions before the armistice, returning to Edmonton with a hard-won understanding of exactly what an aircraft could and couldn’t do.

Building a Bush Flying Network

Edmonton in the 1920s sat at the edge of an immense wilderness. The Peace River country, the Mackenzie Valley, hundreds of miles of boreal forest and muskeg - all but cut off from the rest of Canada in winter, with no roads worth the name and dogsled as the primary means of moving goods and people.

May founded Commercial Airways and started flying north.

He took mail contracts and freight runs, building knowledge flight by flight: which riverbeds could serve as emergency strips, how to keep an engine alive in temperatures that made routine maintenance an ordeal, and crucially - when not to go. In northern bush flying, the judgment to stay on the ground is as valuable as the skill to leave it. A bold pilot who never refuses a departure is a pilot who eventually doesn’t come home.

The Diphtheria Crisis of 1928–1929

In the fall of 1928, reports came south by telegraph: diphtheria had appeared in the Peace River country. By December, it had reached Fort Vermilion.

Fort Vermilion was a community of a few hundred people - homesteaders, trappers, Hudson’s Bay Company workers, Cree families who had lived in that country for generations. Diphtheria is a bacterial infection that attacks the throat and airway, producing a physical membrane that progressively closes it. Children are especially vulnerable. Without medical intervention, the disease historically killed roughly one in ten people who contracted it - and significantly more in isolated communities without access to care.

The antitoxin existed and worked. It was in Edmonton. Seven hundred miles away.

Provincial health authorities contacted May. Could he get it there by air? He said he could.

The Cargo That Could Not Freeze

The most dangerous technical constraint of the mission had nothing to do with the aircraft. Diphtheria antitoxin in 1929 was a biological compound that would be destroyed by freezing. Ice crystal formation would break down the molecular structure that made it effective. If May and Horner arrived at Fort Vermilion with frozen vials, the entire mission had accomplished nothing except burning fuel and risking two lives.

The antitoxin had to remain above freezing for 700 miles in air hovering around -30°F - and growing colder as they flew north.

May and Horner wrapped and insulated the cargo as carefully as they could before departing Blatchford Field on January 2, 1929.

Day One: Edmonton to Peace River

They reached Peace River on the first day and stopped to refuel. Refueling in extreme cold is a task that works against every part of the human body - numb fingers, equipment at the edge of operational tolerances, fuel handling that demands precision from hands that can no longer reliably deliver it. They managed, and pressed on.

That night in Peace River, the antitoxin had to be kept warm through the overnight hours - a practical problem requiring enough heat, somewhere in a northern town in January, to keep a biological compound viable until morning.

Day Two: The Final Leg

The next day they flew north toward Fort Vermilion. May navigated by following the Peace River and its tributaries, reading the terrain by eye the way bush pilots read it - as a map already carried in the head before it can be used from the air.

The land below was uniformly white. White forest, white meadow, white river ice, all under flat winter light that compresses depth perception and makes distance judgment harder than it has any right to be. The instruments they carried were basic, and at those temperatures some were reading inaccurately - pushed beyond their own operational tolerances by the same cold working through the cockpit.

Over stretches of that country, if an engine quits, the nearest reasonable landing area is a very long distance in every direction. You do the math without entirely meaning to, and then you keep flying.

Landing at Fort Vermilion

They put down on the frozen surface of the Peace River at Fort Vermilion. The community came out to meet them.

The antitoxin had survived the flight intact and unfrozen. It was administered to the sick. The outbreak was stopped.

Total elapsed time from Edmonton to Fort Vermilion: under two days. The dogsled alternative under those January conditions: a minimum of three weeks. In the difference between those two timelines, people who were running out of time were given more of it.

Why This Flight Changed Canadian Aviation Policy

May and Horner returned to Edmonton and said little about it. Neither man appears to have been much for self-promotion. They had done what they were asked to do. The cargo arrived in usable condition. That was the job.

But the flight shifted a policy argument that had been running for years. The case that air access was genuine infrastructure - as essential to remote northern communities as roads and railways were elsewhere - had always had advocates. The mercy flight to Fort Vermilion made it impossible to dismiss. More contracts followed. More routes. The network that became the foundation of northern Canadian civil aviation took a measurable step forward.

May later served in the British Commonwealth Air Training Plan during the Second World War, helping to prepare the pilots, navigators, and aircrew who went overseas. He understood better than most of the people making policy exactly what he was sending those young men into. He had been one of them once, a green pilot over the Somme with the Red Baron closing from behind.

Wop May died in Portland, Oregon, in June 1952. He was 55 years old - not old by any reasonable measure, but carrying more aviation history than most people accumulate in three careers.

Vic Horner: The Other Man Who Said Yes

Vic Horner receives less historical attention than he deserves. He looked at the same distance, the same temperature, and the same odds as May, and climbed in. The mercy flight happened because two men decided to go, not one. That is worth saying plainly.

What Bush Flying Actually Was

The pilots of the 1920s and 1930s operated without GPS, without weather radar, without terrain avoidance systems, and without meaningful search-and-rescue infrastructure. The margin between a good outcome and a fatal one was genuinely narrow. They flew anyway - day after day, into the Canadian north and the Alaskan interior and every difficult corner the continent offered - because there were people on the other end who needed supplies, or mail, or medicine, or simply the knowledge that they were not as cut off as the geography made them feel.

That is what bush flying was, beneath the legend. It was connection. It was the airplane doing what roads could not do, faster than dogsleds could do it.

May and Horner flew because someone 700 miles north was running out of time. That will always be enough of a reason.

Key Takeaways

• On January 2, 1929, Wop May and Vic Horner flew diphtheria antitoxin from Edmonton to Fort Vermilion - roughly 700 miles - in under two days, versus a minimum three-week dogsled journey under January conditions.
• The mission’s central technical challenge was keeping temperature-sensitive biological antitoxin unfrozen throughout the flight in approximately -30°F air; frozen vials would have rendered the entire effort worthless.
• May was present at one of WWI aviation’s most debated moments: the April 21, 1918 death of Manfred von Richthofen (the Red Baron, 80 kills), which occurred on May’s very first combat mission.
• The mercy flight became a turning point in Canadian aviation policy, strengthening the argument that air service was essential infrastructure - not spectacle - for remote northern communities.
• Mechanic Vic Horner’s role is historically underrecognized; the mission succeeded because both men chose to go.