May 18, 1980, 8:32 AM—After two months of intense activity and a large outward growth of its north flank, Mount St. Helens erupts. The north flank slides away in the largest landslide in recorded history, triggering a destructive, superheated lateral blast of hot gas, steam and debris. The U.S. Geological Survey estimated the eruption discharged twenty-four megatons of thermal energy, equivalent to 1,600 times the amount of energy released by the atomic bomb dropped on Hiroshima. The eruption propelled ash fifteen miles into the atmosphere; 520 million tons of ash fell in the aftermath. The destruction was immense, and the once vibrant, thriving ecosystem was instantly transformed into a barren, chaotic landscape. Fifty-seven people were killed in the blast and immediate aftermath.
Aviators played a crucial role in the disaster response providing rapid search and rescue, damage assessment surveys, and creating essential communication links in dangerous and unknown conditions. For rescue and recovery units, helicopters were deployed as they could navigate the devastated landscape, land in inaccessible, remote areas, and perform highly specialized rescues.
Garret Cost, today a Docent at The Museum of Flight, was a Bell UH-1 Iroquois “Huey” pilot when the volcano erupted. Assigned to A Company, 9th Battalion at Fort Lewis, Cost’s crews served as back-up for the National Guard, assisting with rescue operations.
Cost’s first reaction to reaching the blast zone was that “it might as well have been the surface of the moon. The ash was very fine, and it was highly abrasive, engines were being flushed after every flight. Dealing with the ash on landing was even more difficult, the rotor wash would stir up a huge gray cloud that reduced visibility to 0 in seconds. It sometimes took several approaches to decide what technique if any would work.”
According to Cost, it was very risky to land in the deep ash, not knowing what was underneath: hard ground or unstable debris. It was also very hot underneath the ash where the trees were buried, and the oxygen-starved trees remained smoldering until a foot or skid gear broke through, allowing fresh air to trigger a sudden ‘belch’ of fire.
Captain Michael D. Cairns, author of Under the Ash, was a Washington Army National Guard Huey pilot at the time. Due to the novelty and danger of the situation, all National Guard flight crews were volunteers. When Cairns’ crew received the call, they departed Yakima for Ft. Lewis, racing just ahead of the expanding ash cloud which threatened to engulf their helicopter. After arriving, refueling and dropping their rocket pods, they were ready to start search and rescue mere hours after the eruption. They did not know what awaited them, flying into superheated toxic gasses, thick ash, falling debris, fast-moving lahars and poor visibility. There was a fear of the significant risk that the abrasive ash posed for the engines, potentially causing flameouts and loss of power.
Reaching their assigned area, Cairns’ crew saw firsthand the extreme, extensive destruction. “The scene was surreal and left all of our crew stunned by the total devastation and the eerie, gray moonscape surrounding us. The air was hot and ‘thick,’ and the smell of sulfur permeated our cockpit. Visibility became increasingly worse the closer we got to the crater.” They were continually forced to fly lower and lower to stay under the ash cloud. While landing, they lost sight of the ground 50 feet above the destination.
A heartbreaking part of the mission was the retrieval of the volcano’s victims, bringing them home for a proper burial. This lasted for months after the eruption; rain washed away a lot of the ash, revealing vehicles and other previously non-visible items, including human remains. Cairns’ final mission was in July.
The rescues were a truly a heroic effort; according to Cairns, 640 helicopter sorties were flown with 140 rescues over 3 days. Even with the hazardous conditions, Cost remembers that the military side of the operations proved safe, as no aircraft were lost, though there was an increase in maintenance due to the erosion from ash. Cairns states, “aside from my combat tour of duty in Vietnam, the life-saving expedition at Mount St. Helens was the most demanding, surreal, and fulfilling flying event I have ever experienced.”
The disaster relief response immediately after the eruption was a massive, complex and ultimately effective operation, saving over 100 lives through their rapid and coordinated efforts despite the intense hazards. True courage was shown by those involved, particularly the flight crews braving the unknown, unpredictable wasteland of Mount St. Helens, risking their lives to save others. Lessons learned from the eruption spurred studies into the aviation safety issues posed by volcanic hazards and improved ash cloud monitoring and communication protocol to better protect aircraft in the future.
[Editor's note: This article originally appeared in the May/June 2026 issue of Aloft, The Museum of Flight's Membership magazine under the title "Hope in Dark Skies: Airborne Disaster Relief in the Mount St. Helens Aftermath."