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October 1, 2005
Julie K. Boatman
"Don't forget to breathe." From the right seat, Lori MacNichol, my backcountry instructor and owner of McCall Mountain Canyon Flying Seminars, laughs as I let out the breath I've been holding back. Minutes ago we dropped into the canyon of the main Salmon River, in Idaho, the third-deepest canyon in the Lower 48, pirouetting around a spire into a place where your sense of scale shatters.
We look at the river, noting the direction of the flow. Most backcountry strips are situated so that you make your landing upstream — and therefore uphill — but Wilson Bar is different. The approach is downstream; the 1,500-foot-long strip itself aims contrarily uphill on the forest-covered bar. It starts with a gentle grade and maxes out at 8 to 12 degrees upslope for the last couple hundred feet. But that slope is all but impossible to judge from our perch. I have the Cessna 172 configured to its canyon speed, one I determined through several trials and found to be 70 knots indicated, with a 10-degree flap setting. The loitering speed is perfect for our survey, which will continue until touchdown.
After circling, as best we can in the narrow halls of the Salmon, we let down to 3,600 feet msl, still nearly 1,400 feet above the strip at Wilson Bar but the starting point for our traffic pattern for this approach. We announce on the backcountry frequency (122.9 MHz) that we're entering the pattern for the airstrip. Learning what MacNichol is looking for as she scouts the landscape, I develop a read of the terrain folds around us, and descend the airplane through a notch in a short ridge that abuts the river. Banking left, I aim for a single dead pine tree on the opposite side of the canyon. Waiting until I'm 100 feet above said tree and what feels like inches from its bowers, I then turn left again to follow the river's course as I continue my descent.
At 2,400 feet I cross a set of rapids. If there's any wind at all, our course downstream gets a fatal push when we make the turn to final; we look for a sign of this wind on the airspeed indicator (gusts may register as increased or decreased airspeed), which is fixed at 60 knots — a couple of knots fast, the upper end of a safe range, but acceptable in this case. The needle doesn't move; the diurnal flow hasn't begun yet today. Once we turn into the strip, we must land, but we can't see the touchdown spot until we make the turn. Either the speed is right, or we go around now while we can still safely follow the river downstream.
At the second set of rapids, we turn. There it is. I focus solely on my aim point, not the trees and the rocks at the far end. I have trouble believing that we'll handily stop on the slim allotment of open field in front of us, but once we touch down, I feel the release of an assured landing. I add a little bit of power to match the grade — like you might on a soft field, just enough to hear the change — and I add more as we take the hill at the end. In every sense — and none — this was a normal landing.
By using techniques learned in mountain flying we can increase the safety of our everyday ops even if those take place solely in the flatlands; the basics hold true no matter where you fly. After spending three days last fall in the Idaho backcountry, flying a regular old 172 into places I would have considered only hiking to before, the trees and hills made their point again. While the scenery rose in spectacular fashion all around, and the consequences of losing focus were truly grave, the crux again came down to three elements that every pilot should have mastered: airspeed control, aim point, and knowledge of the local environment.
The first element of a good approach is a constant, appropriate airspeed. If you sat down and polled instructors about the main thing wrong on nearly every botched approach they have sat through, it would be carrying too much airspeed, or letting the airspeed change dramatically after descending from traffic pattern altitude.
That's why MacNichol, who has logged more than 3,000 hours in the backcountry, and her cadre of instructors start with airspeed control at altitude before taking pilots down into the canyons. We head for a wide valley just east of McCall, crossing the Needles (a prominent terrain feature) into the air above the south fork of the Salmon. The middle-vintage 172 wears like an old sweater as I ease it to a slow cruise airspeed around 90 knots, and then to canyon speed, at 70 knots. I note the power settings and flap and trim configurations for these speeds, and measure on the ground our turn radius as we fly at each speed.
I then slow further to meet an approach speed of 57 knots, with full flaps and a descent rate of 500 fpm. I practice maintaining this descent with the wings level, with the pitch attitude as nearly level as I can muster. The level pitch attitude is a function of the steep glidepath (4 to 4.5 degrees) I'll follow when approaching a landing strip over serious trees and in a confined area, as well as the fact I want to fly a power-on approach the whole way down. I liken it to flying a landing approach in a glider with half the spoilers out — you always have some play either way — because you're just as committed during a backcountry approach as you are in the engineless glider. It's also a way to keep the airspeed steady and the view over the nose consistent. I'll use power — never pitch — to refine my descent rate. Keeping the airspeed rock solid is that important.
While there are mathematics to back up the numbers we choose, and we go through them on the ground, in the air we measure by sight and sound. Every airplane is rigged a little differently; every airplane stalls a little differently.
I find the stall buffet several times and mark at exactly what speed this 172 begins to shudder. The old sweater still fits well.
Once airspeed is under control, it's much easier to put the airplane onto a precise spot on the landing surface. But one of the first things pilots learn as they practice landings is that the spot you aim at isn't the spot where you'll touch down. If you keep your speed in check, and not too far above stall speed, you'll land a lot closer to your aim point.
For most of our flying, aiming for the numbers (at the approach end of the runway, that is) works just fine. You might adjust the aim point if those numbers are particularly close to the end of the runway (no need to eat the green lights on your way to the pavement), or if there are obstacles along the approach.
On the other hand, many backcountry strips have very specific touchdown areas. Miss the spot, and you're in for a wild ride. Changing gradients, lips, water bars (in some cases), and other rough areas cause the unwary to launch back into the air — or the trees — just as they think they're home free.
Case in point: Soldier Bar. The strip sits on a ledge 1,000 feet above the Big Creek canyon floor — but it's really three runways, each about 500 feet long, joined together. The first starts near the edge of the ledge, and has a 5-percent grade. The second has a 7-to-8-percent grade, and the third, which curves to the right, has a 12-percent grade. And there's no transition between each section — just a hefty lip. You can land at the very beginning of the first "runway," or you can land at the very beginning of the second "runway" and have plenty of room (the gradient helps a lot) to roll out in this particular 172. But woe unto you if you put it down just before the lip between the first and second runways — the bounce sends you flying again. This is extremely bad news, since the runway curves, and being freshly airborne so close to stall speed means you cannot turn with it. Trees and rocks await.
Needless to say, please don't try this one on your own. I came away with pages of notes regarding Soldier Bar, but no one could ever tell you with words how to fly it.
Pictures don't tell the whole story either. With apologies to the photographer whose lovely work accompanies this story, and to our friends at the National Aeronautical Charting Office, there are no photos or charts that convey adequately what you need to know about a given backcountry strip before you land — or take off — there.
Likewise, you wouldn't land at any airport knowing only what you could pull up on the computer (no matter how good AOPA's Airport Directory online is). Of course you'd spend time gathering important information about the airport once you arrived on the scene by listening to an automated weather observation system (AWOS) and checking in with the tower or unicom frequency for other traffic. As you enter the traffic pattern, your perch allows you to determine the runway conditions, and you can watch the sock for real-time wind information.
When you approach a backcountry airport you do all these things (and a couple more) — but you're often on your own. In fact, you may be the only human for miles. That's why having a guide with you the first time you fly in can save your life.
A good example is the approach to the Dixie Forest Service airstrip: From the main Salmon River we head north up a large drainage toward the mountain town of Dixie. Just south of town is the forest service strip. On the chart it doesn't appear to pose any unique challenges — at 5,148 msl the elevation isn't too high, considering the strip is listed as 4,500 feet long. The terrain around the strip doesn't look particularly harsh, and as you circle above, the green grass looks well groomed and spacious. A ranger station sits on the east side of the runway, and a road passes nearby, so you aren't even that far into the wilderness.
But this easygoing exterior holds pitfalls for the uninitiated. By "shopping" the strip from a traffic pattern altitude, we can see that the strip is in a bowl, and the approach is not so straightforward — once we're on base, we go blind on the runway and won't see it well until we turn final. And what a final: Our path carves along the south end of the bowl so we can lose extra altitude without increasing our airspeed. When I turn final, I'm nearly on top of the runway. With the gradient, we don't need to land on the first third of the runway, though I'm compelled to do so by the trees and upsloping terrain at the far end. Once we're below 250 feet above the airport elevation, we're committed and won't go around.
Loitering above the airport until we're ready to descend gives us time to assess the conditions. We look at the windsock, and relate its position to relevant terrain features. There may be two windsocks; if so, we look closely at where they're located, and which way they vote. Ideally we want no wind; practically we only accept wind less than 5 knots. That's because for this strip — like many in the backcountry — we have to take off in the opposite direction from which we landed.
Shopping the strip lets us plan that takeoff too, as MacNichol points out. She notes that our climbout follows the drainage to the south, tracing the water below as it takes a 70-degree turn. After we land and take a stretch, I'm glad we've looked long and hard at the possibilities of that drainage. To the south, there's nothing but an impenetrable wall of pine reaching nearly 2,000 feet. If I hadn't known which way to turn to follow the drainage, you could not have paid me to take off that way. The slope to the north also is insidious but far more deadly. We can follow the water downstream, but no 172 could ascend faster than the terrain rises to the north.
Not all airports with serious terrain considerations are located deep in the Rocky Mountain backcountry. The trinity of airspeed, aim point, and local environment rules no matter where you fly. Just ask the pilots who base at the Transylvania County Airport in Brevard, North Carolina.
I came upon this general aviation enclave while flying down to Alabama last year. We had just crossed over the top of Asheville's airspace and the 6,000-foot-plus peaks that surround it and followed a broadening valley southbound to Georgia, where we would pick up gas and hang a right for Alabama — a bit of snarly weather over the Appalachians kept us from a direct route.
But our airplane's unwieldy automatic direction finder (ADF) had been removed for weight, and for a critical stretch of road along our route in northern Georgia the only weather reporting is obtained when you listen for it on an ADF frequency — the automated surface observation system (ASOS) at Habersham County, Cherokee County, and Pickens County airports, to name a few. With a solid blanket of white undercast stretching out at a low level in front of us, I decided to land and pick up some extra fuel before reassessing the weather to the south.
I descended into the valley after consulting the airport information in the directory on board, and as I banked into an overhead traffic pattern, the terrain cupped around us like a green glove. I was so busy remarking at the abruptness of this enclosing as I turned final that I let my airspeed come up a little too much for the 2,900-foot-long runway. The numbers slid below me far too quickly. As I throttled forward for the go-around, the trees stretched taller and in chorus with the hills made their point. Yes, airspeed control, aim point, and knowledge of the environment are critical everywhere we fly.
E-mail the author at [email protected].
Links to additional information about backcountry flying may be found on AOPA Online ( www.aopa.org/pilot/links.shtml).
The AOPA Air Safety Foundation recently completed work on the new "Mountain Flying" online course, and its companion, the Mountain Flying Safety Advisor. The online course and safety advisor cover hot topics for flying over the mountains and landing at high-altitude or confined airports. Subjects include density altitude, weather, aircraft performance, and terrain considerations. By taking the online course and studying the Safety Advisor, you can get a head start on your trip to the high country. As always, any ground course should be supplemented by local ground and flight instruction before you fly over mountainous terrain.
The Mountain Flying online course can be found on AOPA's newly designed Online Safety Center, a hub for the resources offered by the foundation. Pilots can take advantage of the wide variety of online courses, educational downloads (including Safety Advisors and aircraft reports), and safety quizzes. The Online Safety Center also contains an accident database with preliminary, factual, and final reports of accidents back to 1983 for fixed-wing aircraft weighing 12,500 pounds or less.
To access the Online Safety Center, visit the Web site ( www.aopa.org/safetycenter/). From this site you can download the Mountain Flying Safety Advisor ( www.aopa.org/asf/publications/sa23.pdf) and take the online course ( www.aopa.org/asf/online_courses/mountain_flying/). — JKB
Depending on where you live, there are a number of good places to gain professional, local mountain instruction. MacNichol recommends the following:
In addition to these sources, Sparky Imeson has been writing about flying in the backcountry for decades, drawing on his many years of mountain-flying experience. The Mountain Flying Bible has been recently updated (see " Pilot Products," page 155), and Imeson lives in Jackson, Wyoming ( www.mountainflying.com).
Also, Amy Hoover spent many years flying in the Idaho backcountry, and now bases out of Ellensburg, Washington, with her Cessna 180. Contact her through her Web site ( www.canyonflying.com).
The Boise Flight Standards District Office holds mountain-flying seminars each year. Call 208/879-5900 or visit the Web site ( www.faa.gov/fsdo/boi/mountain_flying.htm) for more information.
The Idaho Aviation Association ( www.flyidaho.org) has a wealth of information on its Web site, including a calendar of events.
The Colorado Pilots Association ( www.coloradopilots.org) hosts a backcountry fly-in each year in the state, as well as fly-outs to other mountain areas in the West. A list of instructors can be found on the Web site, with airports served. The Utah Back Country Pilots Association has a calendar posted as well ( www.utahbackcountrypilots.org). — JKB
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