Outdoors/Adventure

The Iditarod Trail on hydraulic wheelskis (full version!)

Editor's note: This article was first published in Water Flying Magazine.

The Iditarod dogsled race is an annual end-of-winter event in Alaska, and last year I spent a week following the race in a Cessna 206 on skis. There were four of us in the party. Alice Rogoff put the expedition together, she owns the airplane and uses it to travel around Alaska in connection with the Alaska Native Arts Foundation (alaskanativearts.org). Writer Christopher Buckley and photographer Sydney Lockhart were on the trip to write about it for Forbes Magazine. I was along to make sure nothing bad happened, which basically meant making sure that at no time would this unwieldy skiplane get stuck. It had all the ingredients of a good adventure, and the plan was to follow the trail wherever it leads, which would presumably be to Nome.

The trail

The various parts of the Iditarod trail have been in use for centuries as a network of winter trails used by the Athabaskan and Inupiaq peoples. It formally took its present form in the early 1900s when gold mining was going strong in Nome and interior Alaska. The gold fields were supplied by boat in the summer months, but in the winter, when the Yukon river froze up and the Norton Sound coast became icebound, an overland supply route was needed. For that purpose, a survey established the present-day Iditarod trail as a winter route between Nome and the ice-free port of Seward. In what perhaps had a certain resemblance to a northern version of the Pony Express, dogsleds brought mail, supplies and news north, and then carried gold from Nome on the backhaul. The larger sleds had 20 dogs and carried a thousand pounds.

When the airplane came onto the scene, it gradually began to replace the dogsled on the mail routes, and by the late 1920s, the use of sled dogs for carrying the mail on the Iditarod trail came to an end. Today the Iditarod trail has become the setting of the "last great race," the annual dogsled race from Anchorage to Nome, and since I've made my living flying the mail in Alaska, I couldn't help noticing the connection of the trail as a mail route. Flying to points along the trail while dogsleds simultaneously traveled the old mail route contrasts the new and old ways of providing transportation in bush Alaska.

While the Iditarod race is a tribute to earlier times, it is also a great thousand-mile tour of the Alaska landscape. The race picks up the historic trail just north of Anchorage. From there it passes through the alluvial river country of the Susitna Valley, crosses through the dramatic mountains of the Alaska range, comes out onto the upper Kuskokwim valley, passes through the gold-rush ghost town of Iditarod, then travels for a while on the Yukon River, and emerges onto the arctic coast of Norton Sound where it alternately traverses sea-ice and a desolate windblown frozen arctic landscape until it arrives at Nome. The trail is only usable in the winter, as much of it crosses rivers and swampy tundra that is impassible in the summer. While I'm sure nothing compares to seeing these thousand miles of Alaska landscape by dogsled, touring it by air is not a bad way to go either.

Flying with a nose ski

During the first days of the race, we did some day-trips out of Anchorage to the Susitna Valley checkpoints, which gave me a chance to get used to the airplane on skis. The skis are FluiDyne hydraulic wheelskis. On land, the wheels protrude through an opening in the ski, and bungee chords hold the skis up to allow operation on the runway. For operation on snow, a plate hydraulically slides back to close the opening in the ski. The wheel rides up on this plate, which has the effect of extending the ski for landing on snow. The skis are generally extended or retracted in the air, but this can be done on the ground as long as the surface is not abrasive. It is really an ingenious arrangement, but the skis are neither light nor aerodynamic. All the cables, hydraulic lines and other components produce enough drag that the airplanes climb and cruise performance almost exactly match what it had on amphibious floats.

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Like floats, skis are rated according to their capacity to bear weight. This airplane has 4000s on the main gear legs, meaning that each ski is capable of supporting 4000 pounds. The standard guidance is to have each main ski capable of supporting the entire weight of the airplane. In addition to that, since the nosewheel sometimes bears more than half of the airplane's weight, there is also a substantial nose-ski, in this case a Fluidyne 2500. When you add it all up, this is a lot of flotation for an airplane that has a gross weight on skis of 3300 pounds. That comes in handy at times, but it also comes at the cost of extra surface friction.

While a nosewheel design isn't ideally suited for skis, the 206 does fine as long as you have a feel for what it can do and don't ask it to do more than that. The main topics with the 206 seem to be taxi maneuverability, takeoff performance and getting stuck, which of course are important topics for any skiplane.

Some of the landing areas we were using had some fairly short usable lengths, and the takeoff technique I settled on was to use 20 degrees flaps and carefully manage the pitch to get the best acceleration. At the beginning of the takeoff, aft elevator lightens the load on the nose ski to noticeably reduce drag. Then as the takeoff progresses, there is a prominent 'sweet spot' that results in the best acceleration. The airplane likes to land just shy of the stall, which makes you more committed to the outcome than you are with a tailwheel airplane. Throughout the after-landing slideout, holding enough aft elevator to keep weight off the nose-ski helps avoid the tuck-forward moment that nose-ski airplanes sometimes experience.

Most of the places we landed had some taxi constraints and when it comes to taxi maneuverability, the nose-ski has limited travel and acts at a short moment arm. Also since the nose steering relies on bungee pressure rather than a hard linkage, the nose-ski tends to get straightened out as you taxi forward. Because of this, sometimes it helps to rock the pitch up and down since aft elevator unloads the nose-ski and lets it swing into position, and then forward elevator presses it onto the snow to give it some authority. It also helps to plan the turns to take advantage of weathervaning and the airplanes natural inclination to go left.

Unalakleet

After the dogteams had made it across the Alaska Range, we flew the airplane 350 miles to Unalakleet, which we used as a staging area for the next four days. Unalakleet is a friendly Inupiaq village of about 800 people, located on the Bering Sea coast of Norton Sound and by Alaska Bush standards it is hardly a small place since it has a grocery store, a restaurant, two churches, a coffee shop and three commercial air services. We arrived there with light snow falling from a grey sky, and the next day it cleared up and the temperature dropped to fifteen below zero with twenty knots of wind. For the next few days much of my energy was spent just getting the airplane's engine warm enough to start. We made some flights to watch the dogteams coming up the Yukon River, and on the day the first teams arrived in Unalakleet, we stayed on the ground and enjoyed the front-row view at the checkpoint. Most of the teams stopped there, while the mushers fed the dogs, spread out some straw for them to sleep on and generally took a rest. After the first several teams left Unalakleet, we left to follow the trail along the lonely stretch of frozen coastline to stage out of Nome. The persistent cold wind was slowing down the dogteams, and it wasn't making things any easier for the airplanes either.

Given the historical character of the race, it seemed appropriate to follow it in a C-206 since this is the basic airframe that is currently doing the work in bush Alaska that was formerly done by dogsleds. More precisely, it is the stretched version, the C-207 that probably comes closest to the modern-day equivalent of the dogsled. Throughout the week that we were on the trail, I noticed something quietly happening in the background that went largely unnoticed. While the mushers, reporters, photographers and all the various onlookers focused their attention on the race, in the background, the commercial operators were unobtrusively going about their day-to-day business of supplying the old Iditarod mail route just as sled dogs had done a century ago. It is the guys working for companies like Arctic Transportation Services and Hagland Aviation who have inherited the legacy of last century's sled dogs, and while the race is a tribute to past history, the hard work of supplying the bush continues into the present. Coincidentally, the Cessna 206/207 hauls roughly the same payload of a thousand pounds carried by the larger dogsleds that ran mail along the Iditarod trail.

I didn't get to see the end of the race, I left Nome early to take advantage of good weather to bring the airplane back to Anchorage. When Lance Mackey was just a dozen miles out of Nome on the home stretch to win the race, I flew by him going the other way, more-or-less following the trail the entire way back to Anchorage. With that I concluded my Iditarod adventure with a five hour flight, covering what used to take a couple weeks of hard traveling by dogsled.

A lot has been written about the Iditarod race and the history that surrounds it, and most accounts go beyond the mere specifics of hydraulic wheelskis and the trail's connection with Alaska aviation. If you're interested in other aspects of the race, you might keep an eye out for Christopher Buckley's article in Forbes. He was traveling in the same airplane and will probably have a different take on the same events. No matter how you look at it though, we accomplished the main objective of getting through the week without getting the airplane stuck. That of course is what really counts.

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