By MARK L. STERN

Earlier this year, I fulfilled a long-held dream of traveling in New Zealand. Over a period of six weeks, I explored this beautiful country by backpacking through remote wilderness areas and sightseeing in its largest three cities (Auckland, Wellington, and Christchurch). Of course, such a spectacular adventure would not be complete without a flight around New Zealand’s tallest mountains.

On a perfect April morning, with no clouds in sight, I climbed into the right seat of a Pilatus Porter and joined seven other passengers on an aerial tour of Mount Cook (12,316 ft.) and Mount Tasman (11,476 ft.). The cockpit panel looked familiar and accessible to me, hardly more complex than a Cessna 182. Under the deft direction of a 7,000-hour pilot in the left seat, the Porter’s large and capable Pratt & Whitney PT6A turbine whirred to life, and we were off the runway in mere hundreds of feet.

Mount Sefton and its icefalls tower over the ramp at Mount Cook Airport. This Cessna 185 is also used for sightseeing tours when there aren't enough tourists to fill a Pilatus Porter.

Ascending from 2,200 ft. to 8,500 ft., we flew along the canyon walls forming the Tasman Valley and enjoyed close-up views of the rugged rock faces, often covered in snow and ice. The riverbed soon gave way to the gigantic Tasman Glacier, the largest glacier in the world outside the polar regions or the Himalayas. This mass of ice runs almost 17 miles long and is almost 2,000 feet thick in some places. As the valley narrowed, the pilot guided the plane around several mountaintops and into several bowls, drawing “oohs” and “ahhs” from the passengers.

It was easy to see how well suited the Porter was to this alpine flying environment. I was astonished to spot a small airplane sitting right on the glacier below us. Before I had time to ask the pilot about it, he pumped a handle to extend skis beneath the fat tires and maneuvered us into an uphill approach to the glacier. It was unbelievable to watch such a landing, with absolutely no ground reference marks for visual cues--the entire scene ahead was pure white with only rocks and icefalls in the far distance.

A close-up of the Pilatus Porter's tailwheel. This particular ski does not change position, so the small tire actually rolls in the snow (as it does on paved runways), while the front skis can be extended far enough to avoid tire contact with the snow.

The engine was shut down, and we all clambered out onto the snow. It was so bright, so pristine, so majestic, so otherworldly, and so close to the towering summits of Mount Cook and Mount Tasman. These two mountains and others in the Southern Alps have attracted serious mountaineers over many years--in fact, Sir Edmund Hillary practiced for his Mount Everest conquest on these mountains. Certainly, I found it easier and safer to just fly up! And, it was even more fun, making snowballs and stomping on the glacier ice with only sneakers.

Mark during his Excellent Adventure in New Zealand

The Pilatus Porter on the Tasman Glacier. The ski tracks show how the plane is parked perpendicular to the glacier's downslope. A tight 90-degree turn from this position is all that's needed to "taxi"for takeoff downhill. The snow covering the front skis indicates how light and fluffy it is.

Thankfully, in this cold, harsh and isolated setting, the engine was easily restarted, and we skied off the glacier back into the air. Again, the pilot flew close to the opposite canyon walls, sometimes so close that even I worried about striking a wingtip. In only a few miles, the skis were retracted, and we landed right back at Mount Cook Airport. The whole tour was such a treat that I was beaming for hours afterwards.