CAUTIONARY TALES OF SKI FLYING
A Story of Hard-won Northern Flying Experience by David Lambton Storey\
Click on Images below to enlarge - all photos property of Dave Storey.
Ski flying has a romantic lure to the young aviator, a romance that when voiced often brings an all-knowing smile to the face of the seasoned bush pilot. In Canada you need no special training or certification to fly an airplane on skis so a prudent pilot seeks out advice from experienced pilots. Their ski flying stories come out slowly, and often seem as understated as the “PIREPS” they give reporting “moderate” turbulence. It doesn?t take long however, to recognize the dread and loathing they feel from some bitter experience with that aquatic excrement called “overflow”.
Over my past 25 years of ski flying, first in my Bellanca Scout and the past 15 in my Cessna 185, I have on occasion experienced the most wonderful perfect soft and solid landings in snow that one can imagine. And, I have experienced a full spectrum of painfully deep thin ice-covered over-flow, widely spaced roller coaster drifts, wet sticky snow, and on one occasion I even found myself crossing on open water which at the time looked just like ice. None of my experiences had prepared me for landing in three feet of soft snow, on top of a foot of over-flow. The old bush pilots I had encountered also failed to tell me what to do if I could not actually get the airplane out. And, hence, following a character building trip to my trapline with my partner Chuck on one unseasonably warm February, I would like to share some of my experience and research for this cautionary tale.
Our trapline is in a deep valley in a remote mountainous region of the Yukon which is inaccessible by snow machine, and is a magnet for fresh snow and fog. The lake we base our trapline from is an absolute wilderness paradise which had an evil reputation for over-flow when we bought it, we learned that was for good reasons!
My first concern on any initial landing on an untracked lake is to look for and avoid overflow, and to find a smooth spot on which to land and stop. The first landing on an unknown lake almost has to be considered a “forced landing”. I knew I required far more equipment and preparation on-board than any basic “winter survival kit” recommended in any manual. I thought I was adequately prepared for our first landing, my “over-flow extraction kit” has essentially transformed my four place 185 into a two place airplane.
Veteran flyer Miles Bradford had told me that he always lands on caribou tracks; “...they know where to go....” he has said. But WHAT CARIBOU TRACKS ? As of this writing we still have yet to see a straight line of caribou tracks anywhere on our lake. I had learned that the time honoured technique for detecting over-flow is to touch down, bounce the skis a few times at flying speed, and pull up to do a circuit and look for water sign in the tracks. If there is no sign of water after ten or fifteen minutes of circling then put down longer tracks, circle and check again, and only then finally land in your own tracks.
In retrospect, following this trip, I would say; THIS DOES NOT WORK in snow more than three feet deep, nor if there is a suspensory crust over the snow covering the overflow. That crust will fail just as you come to a stop.
I also know there might be controversy as to where to stop the aircraft once down. Some say stop in the middle of your tracks. I now prefer to stop “on shore”, and I mean driven right up on shore. Our lake has a swampy snye on one end that has become my favorite place to stop, where, so far, I have not been able to sink far into frozen muck.
A third lesson is that at 3500 feet elevation a Cessna 185 will not take off in much more than a foot of snow without stamping out a runway and leaving it for a while to freeze up in cold temperatures. This process can take a day or more, even with a skidoo.
On this cold February day I had reassured myself with all the tricks I knew, so nothing prepared me for the sinking feeling, somewhere below 10 and before 5 miles per hour, as the airplane dropped and stopped. We were reasonably close to shore, but on deplaning we found ourselves standing in three feet of snow covering one foot of water.
Chuck, my trapping partner, is as tough as a Wolverine, but both of us were brought to complete exhaustion after digging the plane out, turning it around and packing down a runway. (At this time we had no cabin available, deep snow covered all deadfall and potential firewood, and the spruce that might be usefull for blocking the airplane or placing in the slush were buried in deep fresh snow.)
We decided to try to take off but our first attempt at taking off “in our track”, resulted in a dramatic LEFT HOOK by the airplane and we ended back, for a second time, in the heartless over-flow. The next considerable amount of time (all the remaining daylight hours), were spent jacking and cribbing the aircraft up on some logs that we laboureously dug out from the snow and some bits of plywood I had on board the aircraft. Then along with my come-a-long and 100 feet of aircraft cable pulling to assist ruthless applications of the aircraft engine itself, we got the aircraft up out of the over-flow.
But now we found we were puke tired, cold, and wet. We now regretted neglecting to set up a camp before trying to extract the airplane. By now it was dark. Our three foot long“Canadian Tire” snow shoes had proved completely useless in preparing shelter and finding firewood in the deep snow and over-flow. It turns out discovering the shortcomings of ones “survival kit” is a character building experience most bush pilots tend to remember. It was a long cold night with time for many reflections.
By all my accounts, until now, “I WAS PREPARED”? I had a come-a-long, aircraft cable, a generator, a hydraulic jack, two shovels, sleeping bags, extra boots, axe, chain-saw, matches, and a Coleman stove. But, somehow a flashlight and candles had gone missing. And it seemed, “.....certain people.....” had done a fair number on my survival food. Luckily there was still a bottle of whiskey! My buddy Gerd?s advice for similar circumstances had been to “immediately drink the whiskey after getting stuck, then make camp, and only then trying to extract the airplane.” This is great advice Gerd...(Gerd is never short of advice). We used the whiskey to wash down some Pork & Beans eaten directly from the can using some ARDOX Nails as forks.
After a long tedious night of shivering we woke to find our boots completely frozen solid. It was on this, our second day of trapping, that I discovered the true magic of “Bunny Boots”. I filled mine with boiling water, then used them as basins to rinse out my wet socks, emptied them, placed the nicely warmed boots on my feet and finally wore them in complete comfort all the rest of the day at minus 20 Celsius. Other pilots who have the benefit of the experience have told me that they did find themselves falling through thin ice into frigid water while wearing Bunny Boots, and they found the boots actualy provided some floatation and aided them in climbing out over the lip and back up onto the ice. I will never fly again without them.
We came to realize now that we simply could not pack down a runway that was long enough and wide enough to freeze solid and allow us to depart on this day. We finally admitted that we would need a snow machine in order make an iceberg runway to get out of here. And, the only way to get a snow machine in here was to fly it in, and no fixed wing was going to achieve that. My Iridium Satellite telephone was found to work and was used to make the arrangements.
Delmar Washington arrived in due time, a Tundra SkiDoo slung beneath his helicopter, and with extra food and supplies. “You guys don?t look so good!” he told us in typical Delmar understatement. Our enthusiasm was temporary, the Ski-Doo simply submarined into the overflow, and it took all three of us to extricate and drag it, sideways, to shore. It became clear to Delmar, then to Chuck and finally to me that we needed to be taken home, warmed up, and then we could come back with a “PLAN”. As we flew away from the lake I looked down on my 185 and saw several small holes in the snow that I hadn?t noticed before, These would prove significant later.
Having warmed up and hydrated at home I now had ample time to think about the pickle my plane was in. I found very few people who could forecast with authority the inevitable future of an airplane left sitting on a pile of logs, on top of three feet of snow, over one foot of water, over four feet of ice, at a remote wilderness lake. I wondered; would it stay on an iceberg as the snow subsided, or would the heat of the logs erode through the ice leaving the airplane hanging on its wings? I received the full spectrum of opinions and speculations from all kinds of wise men, but it was my helicopter/185 pilot buddy John Witham who was most pragmatic. On hearing my plight he simply laughed and said; “Your first time? Crib it up, go to Hawaii, and come back in six weeks. You?ll be able to fly it off on wheels.”
And that was in fact, the case! On our return six weeks later the aircraft was sitting on clear hard black ice several feet thick.
Since then I have recreated the process at home in my yard by placing a piece of plywood out on the snow as spring approaches. The yard was eventually bare of snow and frozen hard, and the plywood sat, seemingly undisturbed, perched on top of an undiminished pilar of snow.
One late April a trapper friend, John Gibson and I went out to visit my trapline. I observed the same seasonal bare “black ice” and landed smugly on the subsidence ice pack. Imagine our horror when after stopping on shore we found our landing surface was actually only 2” of “crinkle ice” (a deceptive dark veneer of ice that commonly forms overnight on still puddles or lakes.) that had formed over at least a foot of water overlying the ice underneath. Once again, had we broken through at speed the aircraft would have come to a sudden likely damaging stop. WHEW!
While on the subject of “perfect” ice I have on occasion landed only to find the aircraft would not stop. It almost seemed to accelerate as it skated across a perfect smooth surface. This situation requires what outfitter Rod Hardie referred to as the “John Wayne” turn (tail up, lots or rudder, power it around in a 180 and apply full power while pointed the other way.) in this case before you hit shore. Hopefully you won’t hit a hole or ridge and wreck your skis or worse as you slither around.
On one other occasion, I found myself forced to land in failing light. I had the
very unhappy experience of finding that the perfect smooth ice surface I selected for landing and touched down on turned out in fact to be open water. The Scout I was flying on this occasion was moving fast enough to hydro-plane across the surface in a satisfactory manner, but a “suction” seemed to hold me on the surface. Try as I might I could only lift out one ski, or the other alternatively, but not both at once. It was only once I had finally passed up onto “solid” snow and ice near shore that I could resume traditional techniques.
Fast forward four years, In this interval I have built a cabin complete with sauna in which to reflect on proper procedures, should we ever get stuck a third, or is it now a fourth time. We are at this moment just returning from our first trip of the year into the trapline, by Helicopter! We went in and packed out our runway prior to starting our season of “trapping”. And now we will wait a suitable period for cold weather to set our runway and freeze any overflow before we take the 185 back in to land on our iceberg runway.
I have expanded my list of equipment that I now carry for the first trip in (itemized below). The list effectively converts a four place aircraft to a two place aircraft, but that transition is worthwhile for those who tempt fate with a first landing on any unknown lake or a lake with the propensity for over-flow. Herein are the items I recommend be carried in addition to the usual “survival kit”;
• a 1000 watt generator
• an in-Car heater to warm engine (900 Watt)
• a “High-Quality” come-a-long
• 100 feet of 3/16 aircraft cable with swaged eyes at each end
• a four foot “Jack-All”
• two Gear Leg Jack Points (see photos) to secure jack to tapered 185 gear leg
a 4” ice auger (to set “dead-men”) under ice
2 x 12 blocking (to rest the jack-all or put under skis at night)
• an Ice axe
• an Ice screw
• Bunny Boots (with extra Bunny Boots available)
• Yellow Paste Fire Starter
• a Satellite Phone with spare battery
• a GPS with spare battery
• a Solar Charger
• Food for a week
• *LARGE snowshoes with harness compatible with bunny boots
• a Small Chainsaw (oil/gas)
• Wing and Cowl Covers
* In talking with the local (Teslin) Indians, I am now aware that historically the
Athabascans in this area used snowshoes that were as long as they were tall,
and as wide as their forearm long. Anything less, and in particular the the
“Yuppie style” snowshoes are totally inadequate for anyone let alone a two
hundred and twenty pound person with sixty pounds on his back negotiating
several feet of snow on top of over-flow.
The year before last when we flew in, prepared for anything we could conceive of (we had the list, after all), we landed on hard-pack and once slowed to about 10 miles per hour, we taxied smugly towards the “high and dry” shoreline. On cutting the power back when only 30 feet from shoreline, we once again promptly dropped and stopped into eight inches of water. Although we were stopped dead, this time we felt we were equipped, trained and experienced and rescue mode would be a known, if still exhausting, event. We still had one more lesson to learn.
We were packing out our runway, widening our original tracks when, to our horror, we came upon a six foot by four foot lead of open water covered with only a thin veneer of ice. Although the ice on the lake and all around the hole was four feet thick this thin spot was waiting for the unsuspecting. As we stood looking down into the darkness we could see a continuous thin stream of bubbles coming up from the bottom more than ten feet below. To have stepped onto this while wearing snowshoes would have meant certain death. Or, had I slowed the airplane before crossing this section I would most surely have dropped at least one ski into the hole thereby doing considerable damage and costing untold money to rescue it. It seemed fitting to us to try fishing through this hole but even that didn't reduce our level of concern. It was with considerable trepidation that we finished our ski strip and set out 12 miles of trapping trail along the edge of the lake, most of it as close as possible to shore.
The messages are clear here, make your initial ski-trails while the aircraft is still moving as fast as is safely possible, and when walking on the lake on foot, carry a long pole, or rope-up. These holes are deadly, often hidden, and there are several that we now know of on our lake. “Know your lake”, one pilot friend says, with good reason. When we left five days later the hole was once again invisible, covered with a thin skin of ice and a dusting of snow.
There appear to be several reasons for overflow, and I am told at least eight for open leads. The former refers to any situation where the water flows up on top of the ice, often remaining there unfrozen, insulated by the overlying snow. Usually this is caused as the lake water level drops over winter and the ice tends to collapse under its own weight leaving cracks. Temperature changes can cause ice expansion and contraction that can also result in cracks. In both cases water below now flows up onto the surface and lies under the insulating layer of snow where it can remain as a dreaded problem for ski-dooers, ski-planes, mushers or skiers in much of Yukon.
Open water may appear as “dark spiders” which need to be approached carefully. They may be more common in the spring. These may be the result of decomposing vegetation releasing methane that bubbles to the surface to inhibit ice formation. These “gas holes” my research suggest may occur in the same place each year, or they may be warm water upwellings that may be more random. Over a winter the water in our lakes is never still, it “turns over” with slight resulting current. “Spring” holes may result from rising water, sometimes warmer than the rest of the lake, but the relative movement prevents freezing. Once located these holes should be marked, and I often record the location on my GPS.
The underside of ice is seldom flat or smooth. Ice or slurry screens or dams can form under the ice, out of sight, especially where there is current, and they may move and they change the way the ice forms or sublimates. Under water reefs and sub-glaciated water also affect the freezing and thawing of ice. Open leads, often found near creeks flowing either in-to or out-of the lake, can also change over time. Just because any ice was safe last week, doesn?t mean it is necessarily safe today.
Another feature of ice on lakes are pressure ridges. With temperature expansion, or wind, the ice can be forced together, it cracks and is displaced upwards, forming pressure ridges that can sometimes be five or six feet high, and that can run for miles. The larger ones seem more common on larger lakes, and again more often in late winter or spring. Open water is often near at hand when traveling near these ridges so caution is prudent.
An old bush pilot, Phil Temple, told of flying his Cub many years ago over Kluane Lake concentrating on following a wolf that was harassing his horses, when he suddenly became aware of an obstacle in his path. He looked forward barely in time to recognize a pressure ridge had raised a six foot high wall of sloping ice directly in his flight path. Phil described a sudden violent increase in noise and change in direction, but fortunately the Cub had hit on its skis on a sloped side and deflected up and slid over the ice with minimal damage. We suspect the wolf was no longer his priority.
Here are some tips I have found for creating a surface suitable for take-off if you have rescued your airplane from forced, albeit self-induced winter landing. When there is a large area of over-flow, you are essentially making your own ice berg. Some people have suggested that when it is warm, spruce boughs placed in the water will help to form a matrix that is more solid and aids freezing. The concept of snow shoeing a runway might sound like a good idea, but from experience I can tell you packing down a fifteen hundred foot runway in deep snow it is a long and daunting process. A friend of mine once spent 10 days doing just this to get his airplane out.
And, having finally made the runway, it is important to understand and remember the characteristics of a ski plane when you apply full power (that will be necessary) to start it moving. Without brakes you can not prevent the 185 (or most similar aircraft) from hooking to the left under full power. Therefore I find it a good idea to position the airplane to start at a twenty to thirty degree angle to the longitudinal axis to the runway, unless you want to slide off your ice berg (like I did successfully in the picture..).
Several local experts have told me I don?t need a tail ski. A few of these say the original tailwheel helps them stop the aircraft once down, but I strongly disagree. Turning the airplane around on the iceberg is far easier with a tail ski. (Tying a rope loop around one ski or wing tie down also helps). And, for a Cessna airfoil to achieve adequate lift to bring the skis up to ride near the surface of the snow to accelerate requires a tail low attitude. With a wheel instead of ski at the rear the drag is too much. Too much drag means a risk of running off the end of your iceberg at sub-rotation speeds. Should this happen of course you must try to taxi back around in a 180 change of direction and up onto your iceberg runway again, either that or shut down and start all over.
A few final observations; I have also found that overflow does not always “freeze happily” (either consistently, or smoothly) and a pilot may have to beat the daylights out of the overlying snow before getting to flying speed. And, once stopped caution is needed because if there is over flow slush or snow the skis may become frozen down or it may freeze in the ski tunnels and you won’t be able to pump them up or down without finding you have broken a hydraulic line. This $5000 lesson left me with a preference to put my wheels down onto bare ice rather than leaving the skis down. Many skis in this country carry axe scars, a testimony that others have shared similar experiences.
For those poor souls cursed with the romantic dream of flying on skis into untouched wilderness, who have flown into an untested lake and completed a “forced” landing, and who have the prerequisite 150 pounds of jacks, winches, cable, huge snow shoes, gear for ensuring fire even in deep snow, and the techniques described, these tales may or may not prove useful. It may depend on whether they have a tireless partner like Chuck along.
In the mean time I still believe the main reason for having skis on my aircraft is for the margin of safety they provide in an actual forced landing. Cheers.