May 1, 1995
A moose on the runway and a herd of elk on the approach end require a clearing pass before landing on Runway 25 of the United States Forestry Service's (USFS) Chamberlain airstrip. The gray and white Cessna 182 continues to roll to the very end of the rougher-than-a-cob 3,000-foot turf strip.
Having landed smack in the middle of the Frank Church River of No Return Wilderness in central Idaho, the four aviating campers look for badger holes before parking next to a stand of pine trees on the edge of the woods. Thankfully, the ground is flat and free of stones and elk droppings; the fireplace is rimmed by rocks; and 100 yards down a gully, there's a bubbling brook for washing. A wooden outhouse nearby means no trenches will have to be dug. Considering Chamberlain (identifier U79) is 45 miles from the nearest road, this is not so bad.
With the engine shut down, there's an aching stillness. The sun sets late in July, and it's starting to get dark. A long day began with a flight among the jagged peaks and crags of the Sawtooth Mountains, terrible coffee but excellent sourdough pancakes at Stanley Airport (2U7), and a flight to the Indian Creek USFS Airport. That 2,800-foot dirt strip is the jumping-off point for white-water rafting down the Middle Fork of the Salmon River. It's a busy place this time of year, with Cessna 206s and Britten-Norman Islander twins landing and lifting off one after another, disgorging eager rafters and their week's worth of supplies.
"Forget the standard patterns when landing at places like Indian Creek. That's out the window, since you can't fly a straight line," advises Galen Hanselman, as he banks his 182 around a stand of pines just short of the threshold for Indian Creek's Runway 22. Landing uphill and taking off downhill is the convention in these parts.
A picnic of salami on bagels and pickles preceded donning life vests, grabbing paddles and joining a flotilla of rubber rafts and kayaks.
Stands of tall pines on the river's edge glide by as the watercraft rush through ravines, shoot down the narrows, and meander through wide spots on the river. Abnormally low water levels tame the river, and that's just fine for the novice. The fleet stops after a while for a little bit of fly casting for trout and a snack of "gorp" (nuts and raisins), cut-up vegetables, and fruit. Dry air and 90-degree temperature require constant intake of water.
Farther down the river is a stop at the Sunflower Flat hot springs, one of the many in Idaho, with water warmer than any bath. Only modesty in the coeducational setting prevents stripping down completely. A sensuous tiredness infuses the limbs in a setting of slanting shadows, utter clarity of light, stillness, steamy water, and tall pines.
The three rafters hike among the pines to the 2,100-foot Thomas Creek Airport (2U8) runway, nestled between two peaks that cast shadows in the late afternoon. They wait for pilot Hanselman to pick them up for the 40-minute flight north to Chamberlain. Camping gear has already been flown in because of the weight and continuous concern about density altitude. The short strip, 100-degree air temperature, and hills at the departure end call for taking one passenger out at a time — extra flying, but a good decision.
Bush flying has a swashbuckling reputation, but safety is always the first priority, assures Hanselman. Pilots old and bold recommend flying in the cool, still mornings and evenings. Practice your slow flight, fly on the numbers, and hug the sides of the mountains to ensure an escape route, advises Hanselman. Don't drag it in, don't flare too much, and keep the nose high for the taxi.
On takeoff, Hanselman uses a technique that works for him — 10 degrees of flaps on the roll, an extra notch at rotation, lower the nose to gain airspeed. He climbs to 9,500 feet to cruise to Chamberlain.
Setting up the tents and preparing dinner are priorities as darkness falls. The advice to pack light has not been followed by the two tenderfoot campers, who have brought a mountain of sleeping bags, air mattresses, tent poles, and multiple bags.
It's no news that camping involves a major production for every human endeavor, but going to the bathroom is especially troublesome when you have to roust yourself out of the tent in the middle of a chilly night and can't find the flashlight, and an overactive imagination makes sure bears lurk at your back.
The roar of the engine resounds throughout the valley on the morning's takeoff to Johnson Creek near Yellow Pine Airport (3U2). The airstrip, 20 minutes due south, is the site of the annual fly-in of the Quiet Birdmen of California.
Maintained by the Idaho Division of Aeronautics, Johnson Creek is the best airport campsite of its kind in the state. Hot showers, outhouses, bunkhouses, tent sites with grills, picnic tables, and firewood are all provided free.
Ground transportation to nearby Yellow Pine is provided by two pumpkin orange Dodge panel wagons, at $5 plus another 30 cents a mile. The strip itself is smooth turf, but the approach is such that you don't see the runway until you're on final. Stay to the right, because outgoing traffic is coming right at you.
CTAF for all of these back-country strips is 122.9 MHz, but it's also advisable to keep alert for silent traffic.
The contrasting conditions between Johnson Creek and Indian Creek landing strips underline the differing philosophies of the United States Forestry Service and Idaho's Division of Aeronautics. The USFS seems to view the airstrips as necessities for serving its staff, supplying outposts and providing staging areas for firefighting tankers. There doesn't seem to be much concern for the needs of general aviation. In contrast, Idaho's Division of Aeronautics encourages prospective flying visitors with large packets of information, including a video on mountain flying techniques, charts and facilities guide, and mountain flying seminars and workshops. In addition, it recommends Hanselman's recently published _Fly Idaho!,_ a facilities and accommodations guide to the region, with local-knowledge flying tips, geographic and historical information, and humorous anecdotes.
Don't expect radar coverage (see " Skywritings," January 1995 Pilot); controller communications; VOR; instrument approaches; standard patterns; or nice long, smooth runways when flying the back country of Idaho. You'll find that you're in the seat-of-the-pants mode where feel of the airplane, sense of the terrain, and pilotage are in demand. While loran and GPS have made navigation somewhat easier, the pilot has to be able to noodle in and out of valleys; navigate among the craggy peaks; and anticipate downdrafts and escape routes, in order to take advantage of the possibilities that back-country flying opens up.
"Idaho is the last great free flying left in the United States," says John Maakestad, director of safety information and education for the Division of Aeronautics.
The former United States Air Force pilot who traded in an F-4 for a 206 recommends that those unfamiliar with back-country flying first fly to the conventional airports at Challis (U15), McCall (MYL), or Salmon (2U7) to take a couple of hours of mountain flying instruction and get briefings about flying the Idaho wilderness in particular. "It's well worth the time and money at $50 per hour, and it makes your flying safer and more enjoyable," he advises, noting that there are about 30 accidents a year, most of them avoidable.
He also recommends the four-day seminar on back-country flying that the state gives in May, June, and September at Challis. He says that there is now a good working relationship between the division and the Forestry Service but admits more could be done to some of the fields. A limited budget for maintaining the state's 30-plus back-country airstrips requires relying on volunteer fly-ins, where pilots do the restoration.
After the hardcore camping of Chamberlain, it's a shock to have electricity, indoor flush toilets, hot and cold running water, a wood stove, and a refrigerator. The furnishings in the four private guest cabins are like something you'd find in your living room, and alfresco gourmet dining on the front lawn of the Wapiti Meadow's main lodge is routine. The cocktail hour is a chance to meet guests from all over the world, as well as hosts Barry Bryant and Diana Haynes. True to the name (Wapiti means elk in Shoshoni), elk mingle among the horses grazing on the open fields bordered by a trout stream, as the guests eat jumbo shrimp, vinaigrette salad and thick planks of prime rib.
One of the few trout fly-fishing lodges endorsed by Orvis, a well- known supplier of sports clothes and equipment, Wapiti Meadows has 50 miles of stream fishing adjacent to the largest wilderness area in the lower 48 states; the lodge also offers trail rides and pack trips into the mountains. Try a hike up Monumental Summit, elevation 8,600 feet — mountain goat country with spectacular views.
At the summit, add stones to the cairn to commemorate the occasion and scan the jagged peaks for mountain goats. Halfway down is the site of the abandoned Roosevelt gold mine of the 1900s. Now located at the bottom of a lake as the result of a landslide from Thunder Mountain, it's still a source of intrigue as it's believed that a safe full of gold is somewhere down there.
Sulphur Creek, a guest ranch four miles from the Middle Fork of the Salmon River, has its own airstrip with plenty of manuevering room. You can park your Cessna by the horse corral. Land on Runway 26 and take off on Runway 8 of the 3,100-foot grass/gravel strip; watch out for soft turf in the spring time. Bill and Sharon Nichols, who have operated the guest ranch for five years, are renowned for their hearty breakfast that attracts fly- in customers, hunters, and fishermen from all over. Sulphur Creek is surrounded by spectacular scenery, but the naked light bulbs, exposed wiring, and cement floors in the cabins are reminiscent of barracks in the movie Stalag 17. Call it functional; everything seems to work. "Chateau Relaxeau" is the designation for one of the cabins with a swayback roof line.
Bill is the trail boss of the string of five steeds, and Dusty the horse allows you to play cowboy as you "direct" him along the precarious, steep trail up Big Soldier Mountain. Breathtaking scenery makes the chafing of the saddle on the tenderfoot's bottom somewhat immaterial.
Landing on Mile Hi airstrip, elevation 5,831, has "do not try this at home" written all over it. With a 22-percent grade and the first 540 feet of the 1,100-foot strip unusable, it's suitable only for a Piper Super Cub. Hanselman calls it "one of the most hazardous mountain air strips in Idaho, if not the United States," although the lore has it that a Ford Tri-motor actually made it in and out with guests when the now-ramshackle farmhouse served as a hunting lodge.
The staging area for switching aircraft is Cabin Creek USFS Airport (I08), itself a challenge because of 1,700-foot length, high elevation, and no escape should you fly a lousy approach. Minutes after parking the 182, a Super Cub, with Bob "Hurricane" Hannah at the controls, drops in.
Hannah, a world champion motorcycle racer and an ESPN commentator, takes one at a time and plants the taildragger smooth as can be on the goatpath called Runway 19. There are no markings, windsock, tiedowns, or identifier at Mile Hi. You literally fly off the mountain on takeoff. The aplomb with which one intrepid passenger takes the approach and landing causes Hannah to jokingly remark, "Must be either very brave or too dumb to be scared." Mile Hi probably should not be a stop for the occasional visitor unless he or she has along a pilot who knows what's going on. And make sure your insurance is paid up and your will updated. But it's a liberating experience to be one of the few who have landed there. Hannah, in his Super Cub, takes off, disappears over the edge, banks around and reappears. I wave with my cap as he swoops by.
Flying combined with camping, kayaking, hiking, and generally communing with nature clears both the head and heart. No longer insulated by the barriers of steel, glass, cellular telephones, and air conditioning, you are once again in direct contact with the soil, the trees, the earth. In the wilds of central Idaho, an airplane makes it possible.
BY BRUCE LANDSBERG
One hundred feet per minute. That's it — there is no more climb left in the Cessna 172. I've flown the Rocky Mountains before, but never in anything quite this small. Density altitude has always been something of an abstract subject for flatlanders. It takes on a new meaning when there is a mountain in the immediate flight path.
Suddenly, the 172 is in a 300-foot-per-minute sink at maximum power, with best rate of climb airspeed. Flying the leeward side of the ridge, with the wind spilling over the top, is not going to solve my sinking spell. The air will follow the contour of the ground, and it's headed down.
It's time to take advantage of nature's updraft on the windward side of the valley; the Lycoming has nothing more to give. It takes something of an act of faith to snuggle up close to the ridge — like flying formation with the earth. The rock outcroppings are spectacular this close, and now there is lift. Climbing at 200 feet per minute is much more comfortable.
General aviation's safety record in mountainous terrain isn't good. The FAA geographically defines this as virtually all of the states west of the Front Range in Colorado. It also includes all of Alaska and the Appalachian Mountains from Maine down to Georgia. Unless you're flying only short distances, you'll eventually have to confront mountains.
The AOPA Air Safety Foundation conducted a mountain flying clinic last fall in Colorado Springs, Colorado. Thirty pilots signed up to go through the course, which consisted of four hours of ground training and five hours of flight. The reasons pilots gave for attending were remarkably similar: to be safe, to be prepared, to understand how mountain flying differs from low-country operations.
Since 1982, 373 accidents involving the mountains have been recorded in the foundation's database. In general, the ratio of serious accidents — where someone is seriously injured or killed — to total accidents is one in four. Flight in the mountains exacts a much higher toll: almost nine out of 10.
The cardinal rule in the high country is to fly early. Later in the day, the winds pick up. This means downdrafts just when you don't need them. It can also mean more thermals as the sun heats rock-covered ground. Up is good and thermals mean up, but they can also mean a very rough ride. Add some wind, and the probability of moderate or even occasionally severe turbulence increases with the hour hand until sunset.
Conceptually, the phenomena of mountain wave are easy to understand. A rock in a fast-flowing stream creates ripples downstream. Air does the same thing when it flows over a ridge. The waves create upward and downward moving air that can exceed the climb capability of many aircraft. It can be a problem 100 miles or more from the ridge that created it.
Underneath the smooth part of the wave, close to and downwind from the ridge, the air can curl up into a rotor, just like the breakers at the beach. Rotors have been known to flip aircraft out of control and to cause structural damage. It's the mountainous equivalent of wake turbulence, and the solution is the same: Fly high to stay above the turbulence. But if the mountain tops are at 14,000 feet, a normally aspirated aircraft just isn't going to have the steam to handle that. Pilots of turbocharged aircraft must also consider a takeoff or landing in the mountains, or near them. The flight may have to traverse some very turbulent territory before getting on the ground or into the serenity of the flight levels.
There is considerable speculation that a rotor caused a United Boeing 737 to go out of control and crash on approach into Colorado Springs. The NTSB could find no probable cause, but mountain wave conditions were a definite possibility. (More recent 737 accidents/incidents leave a suspicion of a possible rudder malfunction.) We may never know for sure.
Night flight should absolutely not be considered in the mountains. There were 101 night/dusk accidents, and 90 percent of them were serious. The bad record has several reasons, none of which have anything to do with the number of engines the aircraft has — at least on a statistical basis. Engine failure caused by bona fide mechanical problems is rare. It can happen and amounts to bad luck, provided the aircraft was well maintained. In flat country an engine failure is unnerving and potentially hazardous. At night, in the mountains, the cards are definitely stacked against a favorable outcome.
Night compounds the challenges, and weather becomes a major obstacle to safe operation. For example, during an icing encounter, Aspen may not be the best place to go. It is surrounded by high peaks, and the weather may be below landing minimums. For the instrument approach into Aspen the ceiling must be nearly 2,400 feet and the visibility two miles for approach categories A and B. There are three stepdown fixes, and at the missed approach point, which is only 1.4 miles from the end of the runway, there's a lot of altitude to lose — which calls for some fancy maneuvering. The considerable quantity of fine print on the back of the chart mentions the perils of high terrain. In typical fashion, it understates the consequences of not knowing exactly where you are.
The term "middle of nowhere" was invented to describe some mountain airports. There's a strip of asphalt and that's it. No gas, no tiedowns, no repairs, no food, no car, no telephone, nothing — so glad you stopped by.
A straight line course may be the shortest distance, but it may not be the safest — or even possible — given the aircraft's capabilities or the weather. Consider a straight shot from Denver west to Aspen. At first glance it doesn't look too bad. There's a nice four-lane highway that can guide us part of the way. But look at the ground elevation, which runs about 12,000 feet, with peaks above 13,000. To stay 2,000 feet above the surface we're probably going to need turbocharging.
If the engine needs additional oxygen, then so does the pilot. Supplemental oxygen is required anytime we exceed 30 minutes per flight above 12,500 feet, and always above 14,000. You say you don't feel too bad? The thin air doesn't bother you? You just may have the beginnings of hypoxia, which is a feeling of euphoria. This causes normally conservative pilots to do strange and adventuresome things. To avoid the Rocky Mountain high we'll need an oxygen system to go this way or take a lower route.
Now, suppose the need arises for a forced or precautionary landing off-airport. The terrain along the direct route could best be described as pointy. All that vertical real estate is great for climbers, but not so good in a potential emergency. The highway provides scant relief, sometimes snaking its way through tunnels and steep passes.
Pick the direct route and the hills may be high and uninhabited. You weren't planning on spending the night? Neither were several dozen other pilots who were forced down because of weather or mechanical problems. Cardinal rule number two — always file a flight plan. With a flight plan, the FAA will start a telephone search about 30 minutes after your ETA. Serious efforts will begin when the total fuel endurance has been reached. A search could be under way in a few hours. Without a flight plan, according to Civil Air Patrol sources, an average of three days passes before a search is initiated.
If you must make a precautionary or forced landing, land on sloping terrain, land uphill, and be prepared to make a fairly pronounced flare. This means having enough airspeed to trade for pitch attitude adjustment. Try to land in aspen trees instead of pines. They are softer and will absorb more of the impact. As we have frequently suggested, a good set of shoulder harnesses is a lifesaver. Finally, some sort of survival equipment is essential if you expect to survive a night in the wilderness.
An adequate survival kit costs less than $200, and you can make up one yourself for considerably less. Staying alive isn't complicated, but it does require some basic equipment and just a little knowledge. It would be a shame to make a fabulous forced landing in the mountains and then not survive one night because of hypothermia.
Much time should be spent in planning the mountain takeoff. Why? In the low country, unless you're operating out of a really short strip, the airplane has a performance margin. In the mountains the thin air not only robs pilots of energy and judgment; it steals from the engine, the propeller, and the wings.
Fortunately, there is a handy device known as the Top Comp computer which picks up where your pilot's operating handbook leaves off. It will quickly compute the ground roll, rate of climb, and distance over an obstacle. There are some other factors to consider that most light aircraft handbooks don't include, such as runway slope, a variety of runway surfaces, and a significant amount of tailwind.
Take Salida, Colorado, for example. With an elevation of 7,489 feet and a 7,300-foot runway, it should be more than adequate to land a 172. But landing isn't the test. Every year more than a few pilots get into airports they can't get out of. The trouble comes when a takeoff calculation isn't made. Salida is deceptive in that it has a 1.9 percent upgrade on Runway 24, and today there's a gentle seven-knot breeze from the west. Doesn't sound like much; and the terrain off the end is relatively smooth, with little or no vegetation. We can definitely get airborne going uphill. It's going to take only 2,200 feet of ground roll and 3,700 feet to clear the 50-foot obstacle. The kicker is that the rate of climb is only 28 percent of the sea level rate, or 224 feet per minute. The terrain only a few miles from the airport begins to rise steeply, much faster than the aircraft can climb.
Cardinal rule number three: Take off downhill, even with a substantial tailwind. A Beech Bonanza pilot was outclimbed by that not-so- gentle slope out of Salida by taking off uphill with a moderately strong headwind. He never got out of ground effect and slid the A36 into the sagebrush. Accept the downwind takeoff with a long ground roll, assuming the runway is long enough. The departure path is perhaps more critical than the takeoff itself. With an already anemic rate of climb it is a great comfort to see the ground falling away, even if the aircraft is not gaining altitude. Refiguring for a downwind takeoff, the ground roll increases to 2,700 feet and obstacle clearance to 4,300. That's acceptable in these conditions.
There are a few other "gotchas" at Salida and other airports like it. Approaching on the upslope runway, the Cessna is in the visual three- degree descent path. Well, not exactly. An optical illusion caused by the grade is bringing us a little closer to the terrain than is comfortable. Additionally, the runway is on a small mesa. We can expect some downdrafts right off the end when the aircraft is slow and configured for landing. Avoid full flaps until the landing is assured. Then, if a go-around is needed, the airplane will start climbing more quickly.
Approach and departure indicated airspeeds are the same at sea level and Salida, but traffic patterns are flown a little wider than usual at high altitudes because the true airspeed increases about two percent per 1,000 feet, so the ground speed will be 16 percent higher at an airport with an 8,000-foot density altitude. Faster speeds mean wider radius turns and the chance that someone could be suckered into making a steep base-to-final turn to avoid overshooting.
Several times a year, a pilot will attempt to fly up a canyon, thinking it has an outlet. It's frequently a case of mistaken identity, and the results are predictable. GPS helps with more precise navigation in the high country, but several rules keep the locals out of trouble. First, never fly up a canyon — always fly down. If the canyon is at all narrow, or there is any wind, fly above the rim. Flight inside, while spectacular, could bring you up against a hard place, and there is frequently strong turbulence. If the terrain looks rough or jagged, think what it is doing to the air flowing over it.
Learning to read the clouds is critical. Some clouds give fair warning of danger. These include towering cumulus, lenticular clouds, rotor clouds, and virga. My experience with East Coast virga, rain that doesn't reach the ground, has been generally benign. In the mountains, virga may be a tipoff to microbursts and other strong, downward-moving winds. It could be a bad ride or worse, particularly if the airplane has little climb ability left. Sometimes the mountain wave and other turbulence can be active but the air is too dry to give the visual warning of clouds.
If the weather is bad now, however, wait half an hour and you could be on your way again. Mountain flying requires constant assessment and the willingness to change your plans as needed. It contributes to the adventure. The mountains don't care about your schedule or what is convenient.
The advent of ASOS and AWOS automated weather systems in the high country is a mixed blessing. When they go into places where there were no observations before, then we're getting more information than we had before. However, there are some critical phenomena that the systems currently can't detect. They will provide ceiling and visibility, but only right at the sensor. They can't look down a mountain pass to see if it's open. The machines won't tell you of mountain obscurement or lenticulars, cap clouds, or towering cumulus. At stations where there are human observers, it is essential that these people continue to augment the machine reports until sensor technology improves.
Can a flatlander fly safely in the mountains? Absolutely. It's done by thousands of pilots every year, but we have to recognize our limitations and those of our aircraft. Keep the aircraft light, fly early, and sign up for a mountain flying course before trekking into the highlands.
The AOPA Air Safety Foundation is offering mountain flying and Pinch Hitter programs in Colorado Springs June 16-18 and September 8-10. Participants can save $25 by registering at least 30 days in advance. For more information on the day-and-a-half programs, telephone 800/638-3101.
Bruce Landsberg is executive director of the AOPA Air Safety Foundation.
BY PETER A. BEDELL
The mixture of mountain flying and airplanes is not as sweet as flying in, say, the coastal plains. Many ingredients sour the mixture, with terrain and altitude being the most obvious. It's the unseen devils of mountain flying that can turn what would ordinarily be normal takeoffs or landings into a real test of piloting skill and airplane performance.
Everything is against the airplane at higher elevations. In the summer, density altitudes can reach five figures by early afternoon; the thinner air reduces wing, propeller, and engine efficiency to painful levels. Throw a short or soft runway into the mixture and the words "flight planning" take on a whole new meaning.
Unlike flying's early days when almost everyone learned to fly a taildragger in the grass, today's students are simulating short- and soft- field takeoffs in tricycle-gear airplanes on paved runways. The result is an artificial picture and feel for why these techniques should be used.
Grass throws curve balls to both pilots and airplanes. Many things need to be considered, such as: What season is it? (Many grass strips are closed for the winter and spring because of those seasons' generally higher amounts of precipitation.) When was the last time it rained, and how much? Does the strip have good drainage? How tall is the grass? Is the strip on steep or hilly terrain? How much does the airplane weigh, and how is that weight distributed over the three landing gear? All of these issues need to be considered before using a grass strip.
Depending on the field's drainage characteristics, it could take several sunny days for the turf to dry enough to support a 3,000-pound airplane. When overflying a grass strip, look for some signs of field conditions. Dark patches could indicate thick, healthy grass fed by excess moisture. Bare spots may indicate where puddles had formed. If the bare spot is dark, chances are it's still too wet to support an airplane.
If you regularly use a particular grass strip, it may be possible to "read" the conditions and land or takeoff beyond, around, or before the hazardous spots. Be careful not to underestimate your airplane's weight, though; the penalty is often a stuck airplane, a ruined runway, and a peeved airport owner. One final consideration is whether the airplane can get out of the strip with the available runway length, intended load, and additional drag created by wet and shaggy grass.
More so for takeoff than landing, the usual atmospheric conditions need to be considered together with the field conditions: temperature, wind, terrain, and the unforgiving density altitude. Next, check the pilot's operating handbook for a type-specific soft-field takeoff technique and takeoff and landing distances (some POHs have performance charts for grass operation). If the POH has only paved-surface takeoff performance charts, add at least 10 percent to the ground roll and the obstacle-clearing distance for a level, dry grass strip. Since most soft- field takeoff techniques involve using partial flaps, some airplanes' initial climb performance may be hindered, thereby lengthening obstacle clearance margins.
Consult the POH for climb gradients in feet per mile. High density altitudes combined with threatening terrain may ground many airplanes because they can't effectively outclimb terrain. This restricts many mountain pilots to flights early in the morning or near dusk when lower temperatures reduce density altitudes.
Winds are often a deciding factor when planning flights in mountainous terrain. Many pilots simply do not fly when winds are blowing more than 20 knots at the peaks. Rotors, mountain waves, and severe turbulence all combine to make what appears to be a smooth flight into a trying task in a small airplane. Don't be afraid to ask local pilots at an unfamiliar airport about conditions that may be unique to that field. Because of their geographic situation, some airports may have, at certain times of day, unique wind pattern that can pose a threat to the unknowing pilot.
After atmospheric conditions have been determined to be acceptable for flight, check a grass runway for saturation. Dig your heel into the ground at a low point in the runway. If moisture is forced out of the ground around your shoe, then don't plan on flying anything but a Piper Cub with tundra tires. If you determine that the strip is suitable for takeoff, take these precautionary tips into consideration.
Do not move the aircraft from its parking spot until the airplane is ready for takeoff. The wings have probably sheltered the wheels from moisture, and once the airplane is stopped on moist grass (to perform a runup, for example), there is a good risk of getting stuck.
At high-altitude airports, the runup should include leaning the mixture to best power at full throttle (be sure there is nobody parked behind you when you perform the runup). When all checklist items have been tended to, pull the yoke as far back as it will go, taxi briskly, and do not stop unless absolutely necessary. Flaps can be deployed all the way, or at least to the takeoff position, to provide some extra lift while taxiing.
It may take an enormous amount of power to keep the airplane moving. Glance at the tracks you leave behind. If deep ruts are left, stop and get out your checkbook for runway repairs. If there are no ruts, continue taxiing on the highest ground, which is often the center of the runway if the field is properly crowned.
At the end of the strip, turn around without using the brakes and begin the takeoff without stopping. (Don't forget to put the flaps back into the takeoff position if they were all the way down for taxi.) The yoke is still all the way back until the nosewheel comes off the ground. Once the nosewheel breaks ground, release some of the back pressure to keep the airplane from over rotating. The combination of a high angle of attack and thrust blowing over deployed flaps creates a tremendous amount of lift, so don't be alarmed if the airplane gets off the ground in a few hundred feet with the airspeed well below the green arc.
Once airborne, fly the airplane a few feet above the ground while reducing back pressure as needed to avoid climbing out of ground effect. Climbing more than one half of a wingspan above the runway will further reduce the margin above a stall.
When freed from the drag of the grass, acceleration should occur fairly rapidly. Once the best angle or best rate of climb speed is reached, then begin the climb out of ground effect. Flaps can be fully retracted and a normal climb established when cleared of all obstacles.
This technique can be used for almost every tricycle-geared aircraft. Twin drivers, however, must be aware that they are lifting off well below the airplane's minimum control speed (VMC) which demands a quick chop of both throttles in case of an engine failure.
For those flying taildraggers, the drill is more or less the same. The stick should remain all the way back unless the tailwheel starts digging in. The point is to keep the tail as low as possible in case a main wheel gets swallowed into a soft spot, which can cause the airplane to nose over. As in the trike, back pressure should be eased as the airplane accelerates. The liftoff should be made from a three-point attitude.
Landings on soft fields for both nose- and tailwheel airplanes are basically the same. The goal is to land as slowly as possible by using full flaps, with little or no power, and landing at a full stall. For the nosewheel pilot, if the yoke isn't all the way aft at touchdown, gradually apply back pressure to keep the nosewheel up during the rollout. Avoid using the brakes, as braking would tend to force the nosewheel to the runway.
Although it may be easy for students to confuse short- and soft- field takeoffs, the point behind each of them is quite different. For soft fields, the point is to transfer weight from wheels to wings as soon as possible, whereas for short fields, the point is to get accelerated, rotate, and gain the most altitude in the shortest possible distance. The short-field technique is especially useful for getting out of airports with obstructions, whether they be trees, power lines, or mountains.
The short field take-off technique begins by using every inch of runway available to you. Once in position, the throttle is slowly advanced to full power while holding the airplane in place with the brakes. (This may be impossible on a wet asphalt or grass runway in high-powered airplanes. If the airplane begins to skid with the brakes locked, don't fight it; release the brakes and begin the takeoff.) When full power is reached, glance at all engine instruments for anything odd and, if all is well, release the brakes.
As the short-field takeoff roll begins, hold the yoke neutral or somewhat aft to maintain a level or slightly nose-high attitude. Aileron controls should be kept near neutral to minimize drag unless they are needed to compensate for a crosswind. Since partial flaps are probably deployed (consult your POH for proper flap setting), liftoff will occur below the usual rotation speed. Accelerate to the best angle of climb speed, or a speed specified in the POH, until all obstacles are cleared. Once clear of obstacles, retract the flaps. Retracting the flaps too soon leads to a settling effect that can temporarily reduce climb rate.
For complex airplanes, check the POH for the proper gear retraction point. Many Cessna singles call for gear retraction after all obstacles have been cleared. During the long retraction process, the wheels dangle several feet below where they reside in the "down" position, which could potentially snag an obstacle. In addition, a lot of drag is caused by the sideways rotation of the wheels and the exposed wheel wells when the gear doors are open.
Many twins, with their greater thrust, make excellent short-field airplanes — some using half the amount of runway as comparable singles. But, like the soft-field technique in a twin, the danger lies in rotating well below VMC. Don't be in a hurry to retract the gear, either. Wait until you have accelerated through VMC to tuck the gear. If an engine burps, you'll be better off chopping the throttles and landing on the remaining runway than risking a VMC rollover, where chances of survival are close to nil.
The short-field landing technique is very much the same as the soft-field procedure. If the approach is unobstructed, a low, slow power- on approach with full flaps is preferable. When over the runway threshold, reduce power and allow the airplane to plant on the runway at a full stall. There's no pressure to make a greaser; just put it on the mains (or on all three-points if in a taildragger). After touchdown, begin brake application firmly but carefully to avoid skidding. Pull back on the yoke to distribute weight on the main wheels rather than the nosewheel. Retracting the flaps also aids in putting weight on the main wheels and subsequently increasing brake effectiveness. But be extra sure you grab the flap switch, not the gear.
Remember that at high-altitude airports your ground speed will be significantly higher than at fields nearer to sea level. The lower-density air yields faster approaches when you are flying at the same indicated airspeeds. The airplane's true airspeed is higher, but the indicated airspeed should be the same as always. In other words, if you operate out of a 2,500-foot runway in Florida, you may be in for a surprise when you land on the same length strip in Colorado. Your POH is your bible when planning a trip to a high altitude area; study it religiously.
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