In 1975, the Island Airport was used as the base for Olga, a Sikorsky S-64 Skycrane helicopter used to dismantle the crane of the new CN Tower.

Once the pouring of the concrete was completed in 1974, the final stages of building the world’s tallest Tower were about to begin (Tallest freestanding structure in the world 1975–2007. Tallest freestanding structure in the western hemisphere). The last thing to be added to the Tower was the 335-foot steel broadcasting antenna, consisting of 44 pieces—the heaviest weighing 8-tonnes.

Before the antenna could be lifted, however, the giant crane used for four years of round-the-clock service to build the Tower had to be dismantled and brought down.

To do all this moving, “Olga”—a 10-tonne Sikorsky helicopter used primarily for industrial lifting – was flown to Toronto. And on her first trip, tragedy almost struck.

As Olga was removing the first piece of the boom, the crane lurched, twisting and seizing the supporting bolts. Now hovering at about 1,500 feet, Olga was basically attached to the Tower, with 50 minutes of fuel (the job was supposed to take only 12 minutes). The crane couldn’t just be released, either. The operator was still inside. Steel workers scrambled up and burned off the bolts, finally releasing the crane from the Tower. Olga landed with about 14 minutes of fuel left. After this brush with danger Olga performed the rest of the work flawlessly. As each piece of antenna was raised, workers would stand at the top and help maneuver the new piece and bolt into place. And all this where the Tower is only 5-feet in diameter and with gusting winds and freezing temperatures. It took more than three weeks before the final piece of antenna was secured by high rigger Paul Mitchell on April 2, 1975. He even danced a little jig to celebrate—1815-feet above the earth.