Glacier Pilot

A tour of Denali is fantastic, but a tour with a landing is ecstasy

November 1, 2006

My first Alaskan pilot job was in 1976 in Galena, on the Yukon river, as a flight instructor. I am a retired college professor with a doctorate in physics and, while teaching, had summers available to pursue a second career in flying.

Fortuitously, pilots were in great demand that summer as one of the worst fire seasons in history had erupted. I was quickly trained by Galena Air Service and put to work as a bush pilot, flying between local villages and transporting fire workers. I've flown from bases in Dahl Creek, King Salmon, Egegik, Dillingham, Cold Bay, Cordova, and Talkeetna. I have flown north of the Arctic Circle, as far south as Dutch Harbor, and have experienced the complete spectrum of summer flying in Alaska.

Flying in Alaska

Short of being lucky, the most direct pipeline to an Alaskan flying job is The Anchorage Daily News. In March 2001 I answered an ad for a pilot submitted by K2 Aviation, of Talkeetna. As a glacier pilot for K2 Aviation, I would give tours and transport climbers in Denali National Park and Preserve. I had ample experience and good references, and was asked to report in mid-April for ground school and flight training. At K2, I met a distinctly different group of pilots. They were older, and not particularly brawny, as was the typical bush pilot I had worked with before. Instead, they were highly experienced and exuded the confidence gained by thousands of flying hours.

Before the season begins, new hires are given a week of ground training as required by FAR Part 135. The training is supervised by the company chief pilot and includes presentations from senior pilots and outside experts on relevant aviation topics.

The agenda typically includes lectures on airspace, regulations, meteorology, hazardous materials, flight safety, and aircraft characteristics and performance. There is an emphasis on practical topics that are of immediate use to glacier pilots.

Often, officials from the National Park Service and the FAA are present to answer questions and participate in the educational process. Use of safety equipment is reviewed annually, and although it is serious business, it is also comic relief to see pilots practice rapid deployment of fire extinguishers. This involves removing an attached fire extinguisher from an aircraft, pulling the safety pin, and putting out a small practice fire some distance away. It serves the double purpose of a safety drill while getting trainees out of the classroom.

Landing on glaciers

The glacier pilots leaving Talkeetna look toward the Alaska Range and its "Great One" 60 miles away as they lift off from the runway. Clouds on Mount McKinley, or "Denali" as it was originally named, forecast the conditions for the ensuing trip and allow the pilots to formulate an appropriate flight plan.

There is no doubt that landing on glaciers is the attraction in flying McKinley. Without the adrenaline rush associated with landings and changing glacier conditions this could be a boring job. Hauling climbers is arduous work and giving scenic tours can be repetitive. Even though pilots do not get paid while on glaciers, no pilot complains. The thrill of glacier landings and takeoffs, and the excitement of the passengers, makes landing an incomparable experience. A tour of Denali is fantastic, but a tour with a landing is ecstasy.

Training for landing on glaciers is done in the mountain workhorse, a Cessna 185 with hydraulic wheel skis. The complexity level is similar to that of an amphibian aircraft. Training starts with an intense preflight and an analysis of the hydraulic skis and attach cables. In initial practice, skis are raised and lowered so new pilots can feel the process and develop vigilance to prevent ski position errors. Usually the skis are visible on the pilot's side and a visual assessment, along with the sound and feel of the skis passing center, indicates that the skis are deployed correctly. Approximately 70 strokes of the manual hydraulic pump are required to completely change location of the skis, and when the pump lever can no longer be moved, the skis are in position. Knowledge of ski position is critical and a miscue is an invitation to disaster. GUMP (gas, undercarriage, mixture, prop) is still the acronym constantly called out to ensure proper landing configuration. There is no go-around on the glaciers, so things must be right the first time.

Glacier-landing training

Initial glacier-landing training is an individual process where the chief pilot takes trainees to one of the glaciers and teaches the various techniques of landing and taking off. A normal downwind pattern is used and a low rate of descent is established and maintained until touchdown. Maintaining a constant sight picture and a stabilized approach is absolutely essential in glacier landings. Conditions change dramatically from day to day and even hour to hour, and the stabilized approach allows one to fly onto the glacier without bouncing or doing damage. Flat-light landings, where there are no shadows for depth perception, can be accomplished routinely with this technique.

Glacier landings are done on deep-packed snow that covers the actual glacial ice, a surface too rough to land on directly. Snow in the landing areas changes throughout the day, and technique has to be altered to accommodate new conditions. During morning hours, after clear, cold nights, snow freezes and ridges, made by different-size airplane skis, become concrete hard. This can damage landing gear, especially on the smaller Cessnas, and care must be exercised to reduce strain on equipment. However, stress does accumulate and sometimes gear attachments break, necessitating a difficult repair on the glacier.

As the day progresses, snow warms and softens, causing a period when landing is smooth and comfortable. In late afternoon or evening, snow can become very sticky and wet, making taxiing and takeoff difficult. The combination of increased drag, reduced horsepower because of the altitude, and frequent tailwinds can spell disaster. Aircraft may reach a terminal velocity that is below takeoff speed and no amount of searching for that "sweet spot" can increase speed. Sometimes popping an extra notch of flaps will break skis loose and allow flight.

Since glaciers develop crevasses at lower levels, extending a takeoff run too far could lead you into this area.

Almost all glacier pilots have had to abort a takeoff, and in rare instances these aborted runs can result in damaged airplanes. This is an area of judgment that is difficult to teach. Experience and confidence are what counts here and that is why older, high-time pilots seem to be more prevalent in the occupation.

Most commercial glacier landings occur between 5,000 and 8,000 feet msl, where air density and pressure are relatively low. Supercharged, turbocharged, or turbine engines have the best performance. Normally aspirated engines have to be leaned properly for maximum high-altitude performance. There are no brakes on ski airplanes and a stationary runup where you lean an engine is not possible. Consequently, leaning must be done while in motion. Furthermore, the airplane has to be set in takeoff mode prior to landing since if friction does not stop the airplane's motion when turned downhill on the glacier, an immediate takeoff must be initiated. Also, since sliding friction is less than static friction, pilots prefer not to angle park. Without the aid of gravity, crossways parking can make it difficult to get moving on departure.

In contrast, I once had an airplane start sliding down the glacier 10 minutes after it had been stopped. Very unusual, but heat and weight can change coefficients of friction and the forces holding the airplane. Fortunately, I noticed the motion and was able to physically hold the airplane in place until help arrived.

P-factor can cause unexpected experiences on glaciers. Tailwheel load has a strong impact on maneuvering in the snow. Decreasing tail load allows sharper turns and reduces takeoff drag. Raising the tail too abruptly can precipitate a rapid turn to the left and, if accompanied by a left-sloping glacier, can cause an uncontrollable turn.

Can you see me now?

The Alaska Range mountains are huge and multicolored. It is extremely difficult to see other airplanes and almost all tour airplanes use the same routes and passes. If order is not maintained, collisions could more easily occur. To enhance safety, all pilots use a common mountain radio frequency and must know and report location, altitude, and destination frequently.

Each pilot must also memorize a minimum of 50 checkpoints. Immediately after switching from the airport traffic frequency, pilots switch to the mountain frequency and make an initial report that can be heard by nearby pilots. This allows each pilot to develop a mental image of activity in the mountains. Each knows where other traffic is located, and where it is going, and can thereby steer clear of collision courses.

Weather is the most serious safety concern for glacier pilots. Knowing weather indicators and their significance is paramount. Since the major peaks of Mount McKinley, Mount Foraker, and Mount Hunter can be seen from Talkeetna, first weather observations are made on the way to work in the morning. There are days when visibility is more than 100 miles and other days when the mountains are not in sight. There may be a solid overcast at altitudes ranging from several thousand to more than 20,000 feet, or there might be fog with low ceilings.

At other times, cumulus clouds build near the range, or it can be severe clear with lenticular clouds forming on the highest peaks. Conditions have to be evaluated individually, and pilots discuss the situation before taking flight. The chief pilot usually makes the decision about whether to launch or wait, and since Talkeetna is so far from the mountains, a scout plane is sometimes sent to evaluate flight conditions.

Terrifying moments

One of my big concerns about taking a flying position in Talkeetna was the danger I perceived in flying high-altitude passes. I have had terrifying moments both in the Sierra Nevada and on the Aleutian Peninsula as a result of wind-induced turbulence and mountain waves. In five summers of flying Mount McKinley I have not had a similar experience. It appears the situation is quite different in the McKinley area, which is basically a huge block of ice. Since ice stays at the same temperature while it melts or freezes, it keeps the surface of the mountains at a near-constant temperature, preventing formation of extensive convective air currents. If vertical movement does occur, it is mostly from weather systems moving through.

Lenticular clouds on high mountains, like McKinley, are probably the world's largest wind indicators. They form when high winds pass over peaks, condensing moisture in a stationary location. These clouds can be seen from a great distance and tell pilots immediately that caution is necessary in flying the high passes. Winds exceeding 100 miles per hour can exist at the top of McKinley and can extend to lower altitudes at lower speeds. Sometimes fantastic tours can be given below 12,000 feet without a hint of turbulence or up-/downdrafts. At other times, high winds rushing through the passes cause huge downdrafts on the leeward side and updrafts on the windward side. Pilots keep in mind that downdrafts can greatly exceed the climb rate of most airplanes and an escape route is always planned when crossing passes.

Huge summer thunderstorms, spawned in the low, moist valleys, can be another hazard to flight. Even though convection currents are not a huge factor over the icy mountains, in humid valleys the sun can create immense and rapidly moving thunderstorms, causing great winds and turbulence and destroying visibility. Rain, and sometimes hail, comes with the storms, which are hard to predict. Smaller storms can be circumnavigated, but the very large ones can cut off all flight routes, from ground level to thousands of feet. Most often it is prudent to head for home before the chance of getting trapped on the mountain exists.

Since only legally required fuel reserves are carried, choosing a route down a long glacier only to find it blocked by weather at the toe can be a harsh lesson in flight planning. To fly around the "Great One," judgment and experience are invaluable.


Elwood Schapansky, AOPA 283574, of Santa Barbara, California, is a 10,000-hour commercial pilot. He owns a Cessna 180D.