VIH Helicopter Mountain Flying Manual

VIH HELICOPTERS LTD.

MOUNTAIN FLYING

TRAINING MANUAL

Revised April 2005


Contents

Introduction

1. Using this training manual effectively 2. Helicopter type

Part I Ground School

Mountain Flying Chapter 1 1. Course objectives 2. Evolution of mountain flying 3. Psyched out

4. Physical limits and physiological effects 5. Legal limitations and considerations 6. Aircraft limitations 7. Basic techniques 8. Terms used in mountain flying

Topography, Wind, and Weather Chapter 2

1. Topographical and geological structures

Mountain Structure Names

Mountain profile with structure names

The same mountain seen on a contour map 2. Weather systems and their winds 3. Types of wind and air movement 4. Study the wind 5. Wind detection methods 6. Effects of topography on the wind 7. Wind affect on the helicopter in flight 8. Wind affect on the hovering helicopter 9. Mountain weather 10. Icing


Operational Factors Chapter 3 1. Mountain flying checklist 2. Basic elements of good mountain flying 3. Visual reference

Snow operations and reference

Snow landings and reference

Visibility 4. Mountain illusions 5. The mountain recce

Setting up your recce

Clues that indicate wind direction and velocity

Flying and information gathering during the recce

Important points for recce flights 6. Operational hazards

Part II Flight Exercises

1. Precision Handling 2. Confined Areas 3. Effects of Wind on the Helicopter 4. Contour Flying 5. Mountain Recce (figure 8) 6. Mountain Approach 7. Mountain Departure

8. Snow Operations 9. Mountain Illusions 10. Ridges 11. Mountain Tops and Peaks 12. Wide Saddles 13. Shoulders 14. Narrow Saddles 15. Snowfields and Glaciers 16. Pinnacles 17. Cirques 18. Canyons 19. Side Hill Landing Pads

Appendices


INTRODUCTION

1. Using this training manual effectively This training manual is divided into two parts. Part l contains information pertinent to all mountain flying and will be covered during the ground school sessions. Each chapter in Part l will be followed by a closed book quiz. There will be a closed book, final exam on the entire ground school after it is complete. Part II contains the exercises we will be flying. All flight exercises will also be covered during ground school sessions. This manual is designed to incorporate student participation. Ample room has been left for notes and drawings to be added during class.

2. Helicopter type This course is based on the flight characteristics of the Bell 206-B; however, the techniques described herein are relevant to most helicopter types. Caution should be exercised at first when flying a new helicopter type in the mountains. The performance charts listed in the Appendices are for a Bell 206-B, Jet Ranger II.


Part I GROUND SCHOOL


MOUNTAIN FLYING Chapter 1

1. Course Objectives

The term "mountain flying" in many people’s minds conjures up ideas of unknown danger and mysterious flying skills. To those pilots who have not had much opportunity to fly in the mountains, these are intimidating barriers to overcome. Those of you that have had the opportunity to fly in mountainous terrain, have come to realize that extra skill is required but mostly just common sense.

Mountain flying deals primarily with reading the wind, understanding the effects of density altitude and how they affect the helicopter. In mountainous terrain, which really can be described as anything greater than a small bump on the lone prairie, seemingly unpredictable winds in the form of updrafts, downdrafts, and turbulence can develop even in light winds. A helicopter's ability to fly at very low airspeeds allows you to fly it safely in close proximity to terrain. If you haven't learned to understand and apply how air moves over mountainous terrain and the negative effects of density altitude, then you are sure to have a large increase in your "pucker factor" when your helicopter does what you don't expect it to.

The purpose of this course is to increase your understanding and give you practical experience of how to fly safely in the mountains both generally and also in specific types of terrain. It will not make you an expert mountain pilot on the day you complete the course. It will show you what you either did not know or were unclear of to enable you to fly more safely, be more relaxed and productive so as to develop your skills further.

The techniques taught here will allow you to fly with maximum safety and productivity in the mountains. Every area you fly and land on or in has its own peculiarities as far as wind and illusions are concerned. The more often you fly into an area, the less time it will take you to recce it because you will already know some of its peculiarities. In fact in some cases you can come right in and land without apparently doing any recce at all. But even these instances require that you gather information right up to the point of landing. An experienced mountain pilot does this. In fact they have probably gathered more pertinent information than a less experienced mountain pilot who does a more extensive recce. What it all boils down to is information gathering so you can make an intelligent judgement.

We will show you the best way to fly the helicopter, how to judge the wind, how to deal with density altitude effects, and how to evaluate many different types of potential landing sites.


Mountain Flying Chapter 1

2. The Evolution of Mountain Flying The invention of the helicopter created a potential new way to access the mountains. In the early days aircraft performance was severely limited and pilots did not have the benefit of previous experience. The results were often disastrous. Eventually trial and error gave way to methods and techniques and mountain flying gradually became safer. As recently as 20 years ago, mountain flying techniques were still being developed and refined. Good technique was of particular importance when you were heading off into the rocks in a Piston Poppin, tinfoil and tube, high-octane bomb. Almost all accidents in those days carried a heavy toll and resulted in the development of procedures for surviving while working in a mountain environment. The development of the turbine engine helicopter along with the accumulation of knowledge and experience led to a greater margin of safety. Even at the beginning, there was an understanding that there needed to be an effective method of passing on the knowledge of mountain flying. Today, we can take advantage of the experience built on the careers of several generations of dedicated pilots in the form of a mountain course.

3. Psyched Out Flying a helicopter into the mountains out of the flat lands can cause extreme apprehension and anxiety. Once into the mountains the helicopter begins to react totally different as it is being booted, jerked, and bounced by some strange and unseen forces coming out of nowhere.

For an uninitiated pilot, mountains = fear

Imagine yourself in the place of this pilot. Can you identify his mistakes? Shallow short breaths are accompanied by a pounding heart. My grip has become tighter and there is adrenaline racing over my taste buds just as I notice that the hair on the back of my neck is standing up like a porcupine. The cyclic, collective, and pedals are reacting differently and what was once a quiet aircraft is now making noises I've never heard before. The compass and DG are out of sync but it doesn’t seem to matter because I'm constantly changing headings as I try to follow these twisting, turbulent valleys. That damned pass can't be far ahead. I wish I could spend more time looking at the map. I hope I don't take a wrong turn. What!? . . . what happened to my airspeed? I just get it squared away and there goes my altitude!


Mountain Flying Chapter 1 Great! There's the pass up ahead. It's 5500 feet according to the map, looks to be about 1,000 feet lower than my current altitude which is ? . . . Shit! 4500 feet. How can that be? Must be a map error. What 80 mph again! It was just 115 . . . man it’s turbulent around here!! - must be those mountain winds! . . . maybe I should have checked the upper level wind! . . . those cloud shadows are sure whipping along across the ground. Okay . . . I’m just about at the pass. Maybe I can get a picture of that glacier . . . pretty rough air though. Maybe?? If I cut across this ridge I'll be able to . . . wof . . woOF WHUMP !! . . . . WHAT THE HECK WAS THAT ?!? There's dust in here? Dirt falling off the ceiling! Christ! . . . I've lost almost 800 feet !! Sorry Lord I won't swear anymo . . . wwhhHAAMM!!! I'm OUTTA HERE. Where am I? Where's my map . . . how the heck did it get on the back seat? Jeez . . . look at all the power I'm pulling! Gotta settle down, get it together. I feel like my head is spinning . . . take a deep breath, take a break. Right! I'll land up ahead on that big alpine bench, big as a football field and flat as a pancake and once I'm down I can get some blood into these poor ‘ol white knuckles. Approach feels pretty good . . . little steep but I'll take care of that at the bottom, poles right down, hardly using any power, speeds coming off nicely, 150 feet to go . . . sinking FAST! . . . LOST TRANSLATION! . . . PULL POWER . . . Full left pedal, nose is STILL GOING HARD RIGHT . . . Full power I can't overshoot! Ground's coming up fast! Can't make my spot . . . too much slope - 120% TORQUE . . . GOING IN HARD everything is happening in slow motion . . . Please God . . . let me wake up! . . . . . So, how do you overcome fear in the mountains? Learn to detect the wind, understand the weather, become familiar with the various illusions, practice proper techniques, know your performance limitations - be prepared! Replace fear with knowledge and skill!

Welcome to the mountain course!



4. Physical Limits and Physiological Effects Flying at altitudes of 8,000 feet and higher even for short periods of time can have a negative impact on your abilities. Unfortunately, you will most likely be unaware of their effects until the results get extreme, which is too late in most cases. The easiest way to understand these effects is that as you go higher, the quicker and more exaggerated the negative effect becomes. If you have ever had the opportunity to hike up in the alpine, you will understand how quickly you become short of breath. Some basic physiological effects that altitude has on the human body are: Hypoxia: inadequate oxygenation of the tissues. Results in

deterioration of performance and in extreme cases causes unconsciousness

Hypoxic Hypoxia: occurs when there is not enough oxygen in the lungs to be transferred into the bloodstream. For pilots, this is usually caused by flying at higher altitudes, where the air has less available oxygen. The effects become more noticeable above 10,000 feet.

Anemic Hypoxia: occurs when there is sufficient oxygen in the lungs but the blood cannot carry it in sufficient quantities. The most common cause in aviation is carbon monoxide poisoning. Anemia, cigarette smoking, or donating blood can also cause it.

Stagnant Hypoxia occurs when there is sufficient oxygen in the bloodstream but it cannot be carried efficiently to the cells. The most common cause in aviation is high G force. It can also be caused by Arteriosclerosis or heart failure.

Histotoxic Hypoxia: occurs when there is sufficient oxygen in the bloodstream but the cells themselves cannot use it because they are impaired by drugs or alcohol.

Hyperventilation: is caused by breathing more rapidly than necessary. It

results in the lungs having too much oxygen & not enough carbon dioxide. This changes the acidity of the blood, which constricts arteries to the brain & reduces the blood supply. It is common under stress, especially when concentrating on a difficult task and is exaggerated by anxiety and panic. Above 8000 feet hypoxia can bring on hyperventilation. Unlike hypoxia though, controlled breathing can solve the problem.



Gas Expansion/Compression Effects: also known as Barotrauma, it can occur within any body cavity where gas cannot readily escape. It can affect the middle ear, sinuses, teeth & intestines and can be very painful when making ascents & descents.

Decompression Sickness: is caused by Nitrogen coming out of solution in body

tissues at low atmospheric pressure. Bubbles form in the tissues & can produce joint pain, severe cramps and collapse. Scuba divers should refrain from flying for 24 hours if the dive involved decompression stops or if flying above 8000 feet is planned.

Intense Glare: can cause irritation of eyes due to higher light intensity in the

thinner atmosphere at altitude and reflection of light off of snow covered terrain. Prolonged intense glare can cause Conjunctivitis, otherwise known as Pinkeye.

Fatigue: will cause you to tire faster at altitude. Proper nutrition, rest,

and physical fitness are essential. Hypothermia: will be experienced when the core body temperature drops

below a certain level. Higher altitudes even in mid summer can present winter like temperatures and are magnified by wind chill effect (see appendix 1 - windchill chart). This may not seem like a serious problem, especially when inside a heated helicopter, but as pilot in command you have a responsibility to care for those passengers that you transport into the mountains. The type of clothing available may be the difference between being comfortable or suffering from Hypothermia. Always ensure that your passengers are aware of and prepared for the worst, especially if you drop them off with the intension of picking them up some time later.

Frostbite: is caused by the formation of ice crystals in the tissues, often

the fingers, toes, ears, nose or cheeks. It is characterized by white, waxy skin that feels numb and hard. Frostbite can occur very quickly if there is wind chill and can cause permanent tissue damage.

Disorientation: can occur in restricted visibility, when there is no visible

horizon or the only visible terrain is sloping. It can be exaggerated by turbulence.

Further information is available in the Airmanship section, chapter 3 of your A.I.M. and in the Pilot's Guide to Medical Human Factors.



5. Legal limitations and considerations Oxygen CARS 602.32 states that if an aircraft is operated at

pressure altitudes between 10,000 and 13,000 feet for more than 30 minutes each crew member must wear an oxygen mask and use oxygen as long as the aircraft continues to fly above 10,000 feet. Oxygen must also be available to 10% of the passengers (at least one passenger) in this circumstance.

If the aircraft is operated above 13,000 feet at all, everyone on board the aircraft must wear an oxygen mask and use oxygen as long as the aircraft continues to fly above 13,000 feet.

This law arises from the previously mentioned effects of hypoxia at higher altitudes.

Survival Equipment CARs 602.61 specifies the requirements to carry survival

equipment. It is not legally required to be carried when operating with 25 nautical miles of base when the aircraft is equipped with and capable of radio communication. In the mountains however, it is an important consideration to carry the proper equipment even if it is not a legal requirement. A good example is snow shoes.

Weather Limits Most of your flying in the mountains will likely be in

uncontrolled airspace. Provided you meet the requirements, your weather limits below 1000 feet AGL will be ½ mile visibility and clear of cloud. This legal limit is of course the same as it would be in any uncontrolled airspace. In the mountains however, there will often be circumstances where lack of local knowledge or the winds and terrain will require you to set limits that might need to be well in excess of the legal minimum. Remember too that above 1000 feet AGL and above the floor of controlled airspace, the weather limits are higher. Also, remaining clear of a control zone located in a mountain valley while transiting enroute, might not be possible in marginal weather.



6. Aircraft limitations

Altitude Every aircraft has a maximum operating pressure or density

altitude. Well before these limits are reached, aircraft performance will deteriorate as density altitude increases.

Consider the Height/Velocity curve for example. The published chart for the Bell 206 will at some point, no longer be valid. A greater margin of safety will be necessary to stay outside the H/V curve. Hover and climb performance will also deteriorate.

Airspeed The red line on the gauge will no longer be the actual Vne at altitude. In fact, if it’s HOT and you’re HIGH, it might even be less than your normal cruise speed! We will look at some examples in the Flight Manual.

Gross Weight This is especially important to consider when flying in the

mountains. As altitude goes up, obviously, gross weight capability will go down. During the course, we will refer to the appropriate charts to determine hover and climb capability.

Some helicopter types have a WAT chart that may actually be more limiting than the hover chart.

7. Basic Techniques The reason for the development of mountain training programs is SAFETY. BASIC TECHNIQUES are the foundation of all good mountain courses. They have evolved from skilled pilots who understood the theory of what made their machines fly, complimented by precision handling skills, and healthy respect for their limitations. Accidents today are much more likely to be a result of pilot mistakes as opposed to mechanical failure. This Mountain Course will help you improve those odds. Mountain flying in helicopters is the refined use of basic flying techniques combined with a thorough knowledge of the effects of wind, altitude, temperature, weight, and performance. The higher you fly in the mountains, the more you have to allow for the effects of increased density altitude on the helicopter. Specifically, torque may no longer be the first engine parameter to reach its’ limit. Depending on the helicopter type, TOT, or N1 may reach its’ limit before torque does. In other words, less power will be available. Also, the helicopter will react less quickly and less positively to control inputs. There will be a greater delay in helicopter response to control inputs. Increased flight control travel will also be evident. This is perhaps most noticeable in the hover as pedal travel will increase considerably and possibly reach full travel at high power settings.



Flying in the mountains requires that you constantly use your skills in detecting the wind. You must understand how the topography alters its’ direction by causing updrafts, down drafts and turbulence. You must also become familiar with the various illusions and know how to counter their effects. As with flight at lower altitudes, you can use the wind to your advantage. In fact, the loss of performance experienced at higher density altitudes can be more than compensated for by favorable winds (steady winds and updrafts). Contour flying is a good way to learn how to feel the wind through constant altitude and airspeed control of the helicopter. It will also show you some of the illusions that you will be exposed to. Although contour flying is a good method of determining the wind, especially when learning, it is usually only used in abbreviated form in day to day operations. The Mountain Recce is used to find all relevant information to execute a safe approach, landing, and takeoff, complete with abort and/or overshoot routes. Using this recce will allow you to pick out and assess your exact landing spot, where you may have to execute a no hover landing, depending on conditions. A helicopter can of course be brought in for an approach and landing in high mountainous terrain in just as many varied ways as it can at lower altitudes. More caution must be used in the mountains however, and the Mountain Approach is a safe method to use. The Mountain Approach is a flat or shallow angled approach with airspeed gradually decreasing to your landing spot. This method is a good way to counter the effects of density altitude and adverse winds. Use this technique when you can. There will often be circumstances though, where it is not possible to employ this technique because you are below the tree line or there is some sort of obstacle on your approach. The important thing when making an approach is airspeed and power control – the right amount at the right time. In other words, if your approach has to be steeper, you’ll have to reduce your airspeed sooner in order allow yourself the opportunity to apply the power required to control your rate of decent. It’s all about energy management. If it’s done properly, a steeper approach won’t cost any more power than a shallower one. Always work at refining your precision handling skills. It will aid you in detecting and evaluating the wind and to manage the effects of density altitude on the helicopter. Chances are that you may currently be flying without visualizing the air movement around the terrain or fully understanding how the helicopter is affected by it. With the guidance of an experienced Mountain Pilot, this course is designed to refine your skills and teach you these fundamentals and techniques. We will be demonstrating and you will be practicing Contour flying, Mountain recces, Mountain approaches and departures on each (and hopefully every if the weather co-operates) topographical feature described in Part 2 of this manual.



8. Terms Used in Mountain Flying Demarcation Line - The line that separates smooth up flowing air from turbulent

down flowing air as it moves over topography Disc Loaded - when sufficient power is applied early enough on an

approach to yield a zero or low controlled rate of descent with gradually decreasing airspeed.

Double Horizon

Technique - A method used to maintain a constant angle of descent, climb, or level flight by aligning a near and far object.

Density Altitude - Is pressure altitude corrected for temperature. The helicopter

will perform according to density altitude. Drop Off - Down sloping ground along the flight path, which can be

used as an easy abort route if adverse conditions are encountered (an unexpected downdraft or tail wind).


Topography, Wind, and Weather Chapter 2

1. Topographical and Geological Structures

Mountain Structure Names Arete - A spiny ridge formed on the opposite sides of an

ancient drainage divide. Bergschrund - A crevasse that separates flowing ice from stagnant ice at the head of a glacier Braided Stream - Can be found downstream from the toe of a glacier. Cirque - A semi-amphitheatre of large size, that has been

excavated by, or is under the influence of ice. Cornice - An overhanging mass of wind sculpted snow

projecting beyond the crest of a ridge. Crevasse - A fissure, often deep and wide, in a glacier or ice-

sheet. Gully - Is smaller than a ravine, which is smaller than a

canyon, which is smaller than a valley. Moraine - Debris scoured from adjacent ground by a glacier,

which generally parallels the direction of flow of the glacier.

Peak - The more or less pointed top of a mountain standing

above the level of the range or surrounding country. Pinnacle or Horn - Formed when several cirques enlarge and converge. Saddle or Col - A mountain pass, formed by the same process as an

Arete, resulting in a lower, saddle shaped surface, beneath the remainder of the summit area.

Tarn - A small lake occupying a depression in a cirque. Talus Slope - Also called a Scree slope, it is the accumulation of

broken rock that lies on a steep mountainside or at the base of a cliff. The material is sitting at its steepest possible slope—its angle of repose.


Topography, Wind And Weather Chapter 2

1. Topographical and Geological Structures

Mountain profile with structure names


Topography, Wind and Weather Chapter 2

1. Topographical and Geological Structures (Cont’d) The same mountain seen on a contour map



THE

SINGLE MOST

IMPORTANT ASPECT

OF MOUNTAIN FLYING

IS THE

WIND



2. Weather Systems and Their Winds

West Coast Weather Coastal British Columbia weather can be roughly divided into two types. Winter weather and summer weather. This is due largely to the annual change in the tilt of the earths’ axis. The resulting shift in the suns’ heating of the hemispheres changes the pattern of weather system movement. During the coldest part of the winter a high-pressure area is situated roughly over the Hawaiian Islands. Intense low pressure systems develop and slide north of this high-pressure area across the North Pacific and on to the BC coast. At the same time a cold high-pressure area, consisting of Continental Arctic air, exists over Canada’s interior. As these storms and associated fronts move across the coast, they combine with the orographic lift caused by the coast mountains to produce low ceilings and heavy precipitation. The warm North Pacific current keeps temperatures above freezing at the surface with snow falling at higher elevations. With each approaching weather system, surface winds are usually strong southeasterly. Behind each system, winds usually veer to southwesterly. The Maritime Arctic air behind the cold fronts is often moist and unstable. This gives rise to extensive convective cloud and frequent heavy showers. The mountains normally act as a barrier that prevents Continental Arctic air from advancing onto the outer coast. Occasionally though, an extensive pool of this air will push its’ cold front across the coast range from the interior and onto the outer coast. Cold northeasterly winds will flow out through valleys and inlets. Weather is not usually a problem as the cold air is quite dry. When the arctic air retreats, warm, moist air from the offshore low creates an advancing warm front. Snow, icing conditions and generally nasty weather will prevail. During the summer months, the high-pressure area that was situated over the Hawaiian Islands in the winter, has now moved over most of B.C. Weather systems, now less frequent and less intense, are forced around the high pressure area and move on shore over the north coast and across the northern part of the province. In the high-pressure area winds are usually light and variable. The low-pressure systems, when they do occur, still bring their typical increase in the precipitation and wind with lower ceilings.


Mountain Weather The eastern slopes of the Coastal and Rocky Mountain ranges have less cloud and precipitation than the western slopes. This is because air flows predominantly from the west off the Pacific and undergoes orographic lift on the western slopes of both ranges. For the previously mentioned reasons, low ceilings and visibilities are much more predominant in winter than in summer. Also in winter, mountain valleys experience a high incidence of fog caused by radiation and Katabatic cooling. Jet streams from the west or southwest will frequently set off mountain waves. These will be stronger and more dangerous during winter due to stronger Jet Stream winds. This is the phenomenon that causes Chinooks east of the Rockies. Occasionally, an upslope condition on the eastern slope of the Rockies, will cause weather conditions to be worse than on the west side, reversing the usual pattern. When the high pressure area dominates in summer, precipitation usually comes in the form of afternoon thunderstorms caused by daytime heating and orographic lift. The weather systems and associated wind described above are, of course, quite variable and merely show the general trend through-out the year.

3. Types of Wind and Air Movement Wind is formed in several different ways. Strictly speaking, wind is described as the horizontal movement of air, but the mountains generate local winds, which can flow in any direction because of interference from the terrain. The following paragraph and the definitions describe the majority of wind types or air movement you will encounter in mountain flying: It is a nice sunny summer afternoon in the mountains of British Columbia. A high-pressure area is situated over the province with a low-pressure area off shore. The prevailing wind is out of the southwest at 10 knots. As the wind blows across the topography a valley aligned at an angle to the prevailing wind in a East, West direction causes the air to flow along the valley creating a valley wind. On the north side of the valley a narrow saddle allows the air to flow through in a venturi or funnel effect. The valley meanders and in some places the valley wind is quite light. As the sun heats the ground, the air above it rises because of convection. Flying through this air you would encounter thermal turbulence. Air heated on the side slope of the valley follows the slope of the ground as it rises causing an Anabatic wind. The next valley to the west has a glacier at one end. The air next to the glacier is cooled by the ice and is quite a bit colder than the surrounding air in the valley. This colder, denser air flows down the surface of the glacier as a Katabatic wind. It is the strongest and deepest near the toe of the glacier. As the prevailing wind moves over a mountain in the area, it is forced to rise. This is called orographic lift. A helicopter flies toward the mountain from the downwind side and experiences some mechanical turbulence. Then as it gets closer to the peak the pilot flies into a downdraft requiring more power. On the upwind side of the peak, much less power is required, indicating the helicopter is flying in an updraft.


Topography, Wind and Weather Chapter 2 In preparation for landing on the peak the pilot flies close to the contours in the boundary layer to help confirm the wind. On final approach to land on the peak the pilot is cautious because although there is a suitable level landing site, the ground on the windward side next to the landing site is quite steep and the pilot is concerned about backlash on landing.

1. Prevailing Wind The prevailing wind is the upper level wind. It is generally stronger at

higher altitudes and decreases in velocity as it comes in contact with the terrain. All other winds can be grouped together as local winds.

2. Mountain Wind A mountain wind is caused by the prevailing wind flowing over a mountain

range. It can result in mountain waves forming when the velocity and the stability of the air are just right. It can also be used as a general term when describing any wind associated with mountains.

3. Valley Wind Is wind flowing along a valley. Valley winds may be caused by the prevailing wind which tends to be redirected along a valley. They can also be caused by the heating and cooling of the earth’s surface. This tends to cause winds to flow up valleys during the day and down valleys at night.

4. Katabatic Wind Cold air flowing downhill. This can occur on a small scale such as over a

single glacier or snowfield. It can also occur on a large scale where the cold air from higher elevations, runs down several different drainages and then down a major valley.

5. Anabatic Wind Warm air flowing uphill. It occurs in the daytime and is caused by the sun

heating mountain slopes.

6. Convection / Thermal Updraft Air warmed at the lower levels which is transported aloft by vertical

motion.

7. Orographic Lift Air that is forced aloft as it blows against a topographic feature.



8. Mechanical Turbulence Air that is disturbed into a series of eddies as it moves in contact with the

ground.

9. Thermal Turbulence Rising thermal currents of air generated by surface heating.

10. Updraft Air that is moving with an upward component.

11. Downdraft Air that is moving with a downward component.

12. Funnel effect / venturi effect Air that rushes through a mountain pass with increased velocity.

13. Backlash When wind blows up a vertical or near vertical rock face that abruptly changes to level ground, a pronounced back eddy is formed just over the top of the vertical face. Backlash is a situation that has the wind curling back, at surface level, towards the cliff in the opposite direction. The wind generally has to be 10 KTS or more to initiate backlash conditions and the event itself can be quite severe.

14. Boundary Layer As the air moves over terrain it forms a layer of air next to the terrain. The

boundary layer can be quite thin in a light wind and increase in depth as the wind velocity increases. It can usually be found moving up the hill on the upwind side and down the hill on the downwind side. However, depending on the shape of the terrain and the wind velocity, downwind eddies can result in air flowing up hill on both sides of a mountain.

15. Sea Breeze / Land Breeze

Unequal heating of air over land and water results in breezes near shorelines. While the land is heated by the sun during the day, air above it rises and a cool breeze blows in from the water. As the land cools off at night, air pressure over it increases and a cool land breeze blows out over the water.



4. Study the Wind Look up! What are the upper level winds doing? What direction are they blowing from? What do you estimate their speed to be? What affect will they have on the area you are headed for? What information do the clouds give you? Every day of mountain flying should begin with an interpretation of the upper level winds and then constant scanning of the skies thereafter. It is essential that you learn to use every clue that indicates wind velocity. The wind is a dynamic force that is constantly shifting direction and velocity. Whenever you have the opportunity, sit on a ridge or knoll in the mountains and take time to study the wind over a 20 minute period. On a calm day the wind will have intermittent surges. From zero wind it will slowly build to about 5 - 10 knots and slowly dissipate back to zero. These surges can come from a variety of directions but are quite often related to convection or thermal activity. If it is a windy day you will notice gusts that travel with the wind are capable of coming from different directions, usually +/-45 degrees of the general wind direction. You can feel changes in temperature and the direction it is moving. You can smell it and you can hear it. It may not actually be alive, but it does exist. It is without a personality, yet it can be down right nasty. It is a real force and may the force be with you. To observe and study the wind will help you understand its unpredictable nature. Mountain approaches are designed to counter these unpredictable conditions.



Demarcation Lines

Their angle and origin is affected by wind velocity and the shape of the terrain



5. Wind Detection Methods List the different methods and clues to finding the wind's direction: 1. 21. 2. 22. 3. 23. 4. 24. 5. 25. 6. 26. 7. 27. 8. 28. 9 29. 10. 30. 11. 31. 12. 32. 13. 33. 14. 34. 15. 35. 16. 36. 17. 37. 18. 38. 19. 39. 20. 40.

6. Effects of Topography on the Wind Air flow over mountainous topography is best visualized as water flowing over obstacles in a creek or stream. Air reacts as a fluid would. When the velocity increases so do the reactions to the obstacles that interrupt its flow. As the velocity reaches a certain speed in relation to the physical shape of the terrain, pools of backlash and turbulence form on the back side of the obstacle. Recognizing where these areas are can eliminate the possibility of flying through conditions that are unnecessarily rough and uncomfortable for you, the helicopter, and your passengers. The chance of setting up an unsafe approach through these areas should also be eliminated. Knowing the various wind types, where they are found, and how the flow patterns evolve around the topography, is essential for safe mountain flying.



Mountain waves are often generated by the Jet Stream

They are more likely and more frequent in winter

The scenario depicted above occurs in strong prevailing winds

In weaker winds the cap cloud will extend past the mountains

The best places to fly if the above conditions exist are well above the peaks or down low in the valley bottoms

In valley bottoms turbulence is more frequent but less violent



7. Wind Affect on a Helicopter in Forward Flight The wind has the following affects on helicopter handling: Drift: Usually caused by a crosswind or quartering

wind. Fish-tailing: Indicates you are downwind. Control

responses are sloppy. Apparent Ground Speed: Seems slower than indicated air speed when

flying into wind. The reverse is true when flying downwind.

Power Changes: More power required to maintain altitude while passing through an area of down drafting air. Conversely less power required while passing through an area of updrafting air.

8. Wind Affect on a Hovering Helicopter The wind has the following affects on helicopter handling: Loss of Tail Rotor Authority: An un-commanded right yaw, which does not

subside of its own accord. This may happen any time the wind is blowing from 120o through 330o relative to the nose of the helicopter at the hover or low airspeeds. (see Appendix 10)

Critical Relative Wind Azimuth Area : Indicates an area that demands more

power. If the relative wind is between 0500 and 210o and you are hovering in area "B" of the hover ceiling charts you may run out of pedal and/or exceed TOT limits. (see Appendix 11)

Running out of Aft Cyclic: In slow flight with strong or gusty tail winds,

nose drops and tail rises with helicopter drifting forward. A similar situation can arise when approaching side hill pads with an up-slope wind.

Running out of Pedal: At altitude greater blade pitch angles and

therefore greater left pedal travel is required to compensate for the less dense air. On occasion, pedal travel may be insufficient to provide the required thrust.



9. Mountain Weather Mountain weather can be as varied as the terrain you fly over and work in. The reason is the mountains themselves. They force the air to move vertically, thereby producing very localized weather patterns. It can be a nice day in the valley you are in, fly around the corner and surprise!! Fortunately, the reverse can also true. As air rises, or is forced to rise by the topography, it generally cools off. Clouds can form in rising air and dissipate in descending air. They take different shapes as they form and dissipate. Clouds play an important part in helping you read what the wind currents are doing. They are very often your best clue to the strength and movement of the wind. Learn their many forms and what they mean.

10. Icing Mountainous terrain is notorious for generating icing conditions. When temperatures are between 0oC and -10oC, icing conditions are the worst. When you fly up into the mountains, you are doing just that - flying UP. This means colder temperatures and possible icing conditions when you go above the freezing level. Mountainous terrain promotes vertical movement of the air and any water droplets that happen to be in that air. If you are above the freezing level, and flying in and around moisture, you may encounter icing conditions. Warm moisture-laden air blowing up a mountainside through the freezing level contains a large amount of super-cooled water droplets, which will freeze on contact with anything, including your helicopter. The stronger the upward flow of air, and the greater the moisture content, the greater the potential for serious icing. BEWARE!! If you inadvertently fly into it, you might be able to land, or fly below the freezing level before you fall from the sky!!! Refer to “Helicopter Icing and Winter Flying” for additional information.


OPERATIONAL FACTORS Chapter 3

1. Mountain Flying Checklist 1. Check weather and winds aloft 2. Consider load and fuel requirements 3. Check performance for expected conditions 4. Brief Passengers 5. Ensure suitable clothing and footwear for anticipated conditions for all

persons on board 6. Extra equipment such as snow shoes or snow deflectors

If you don’t wear it . . . . . . . . . bring it!

2. Basic Elements of Good Mountain Flying 1. Know your helicopter's performance at altitude (see Appendices 1 - 8) 2. Know the wind at all Times 3. Precision handling 4. Complete your recce 5. Abort and overshoot routes 6. Low controlled rate of descent

7. Power on / disk loaded 8. Gradually decreasing airspeed 9. Land into wind (as conditions permit) 10. Spot landing


Operational Factors Chapter 3

3. Visual Reference Mountain flying is most definitely VFR flying. Therefore, visual reference with the ground is vital. Usually a pilot can maintain straight and level flight with reference to the natural horizon. In mountainous terrain though, the natural horizon may not be visible either because of weather or because you are down in a valley. Instead, you must use other clues to establish what is level and what is not. You can rely on a combination of your own sense of balance, general awareness of what is level, and precision handling of the helicopter, with help from your instruments, to keep your helicopter upright. Illusions come into play here. Once you become familiar with illusions, and how they can fool you, you can overcome the misleading information they appear to be giving you. When flying in marginal weather, the quantity of visual references diminish. You must be careful not to lose what references remain, lest the earth rise up and smite you.

Snow Operations and Reference Snow presents its own set of operational problems. When snow is falling, it obscures visibility and the usual references that are used to help control the helicopter in VFR flight. You can have 10 miles plus visibility flying over snow-covered terrain and still not be comfortable. Snow covers up perfectly good references with a beautiful blanket of white, which can be hard to see and land on. White out occurs when no horizon, shadows or clouds are discernable. Orientation and depth perception are lost. White out obscures all visual references. In VFR flight, you are doomed!!! On landing, rotor downwash can do it. You must have a reference in order to prevent it under these circumstances. Grey-out doesn't involve any blowing snow, but is caused when white snow is covered by shadow making it impossible to see where the surface is. Flying over snow-covered ground is best when the sun is shining on it. Then you can see exactly where the surface is.


Operational Factors Chapter 3 Snow Landings and Reference It is easy to become disoriented and drift across the snow when trying to land if you don't have a stationary surface reference. Take the following precautions when conducting snow landings.

Find a landing site with multiple reference clues. This could be exposed rocks or vegetation poking through, or even a dirty surface snow.

Contrast on a crusty uneven snow cover will make shadows to help define the surface.

Fly in at light weight and check it out.

If you are making multiple landings and poor references exist, put in some man-made references – like flags.

White-out conditions caused by rotor downwash on landing require very disciplined approaches maintaining translation as long as possible with a short, quick, level, zero speed, spot landing to a reference point.

Be cautious of grey-out and intermittent grey-out caused by shadows over your approach and landing site.

Use your landing light if you anticipate difficulty in seeing the landing surface. The light will shine on the surface snow and give you a reference.

On landing, tamp the helicopter into the snow until skids cannot sink any further. Favour a nose-down attitude to keep the tail in the air.



Visibility

The visibility we are talking about here isn't measured in miles, but how well you can see out the window. Do yourself a favour and keep your windows clean so you can easily see those references. A good pair of sunglasses and a peaked hat or helmet and visor are essential to guard against intense glare. In some conditions, you may want to use both sunglasses and a visor at the same time. Long term exposure to too much UV radiation can cause cataracts of the eyes.

4. Mountain Illusions

Imagine the following scenarios:

You have just flown over a ridge and without intending to, you find your airspeed increasing.

You recce a confined area in some trees and when you come in to land you find the trees are a lot taller than you expected.

As you come in to land at an unprepared site, you slightly overshoot your intended landing spot. In the hover you look back and realize you’re hovering over a downslope.

The above are examples of illusions:

Needless to say, you will fall prey to illusions. The illusions identified below can catch you unaware and there is no single way for you to avoid them all, apart from being familiar with them so you can avoid being fooled.

Illusions come about because your brain is playing tricks on you. Your brain is constantly comparing the information sent to it from your senses, primarily your eyes and the balance organs in your ears. When your brain receives conflicting signals, you can fall prey to an illusion. Vertigo and disorientation are two examples of this. Fortunately, our brains have the ability to sort out these conflicting signals and make sense out of an illusion.

In the mountains we are prone to illusions in part because there isn’t a constant horizon to refer to. As we fly along, the ground appears to move up and down below and above us. As we discuss the illusions identified below, see how many are familiar to you.

1. Upslope Illusion This illusion is created when flying over rising terrain resulting in the tendency to cause the helicopter to loose airspeed and gain altitude. The best way to counter it is to anticipate it and scan your airspeed and altimeter.


Operational Factors Chapter 3 2. Downslope Illusion This illusion is created when flying over descending terrain resulting in the

tendency to cause the helicopter to gain airspeed and loose altitude. Again, anticipate the illusion and use your instruments to overcome it.

3. The Broad Slope Illusion This illusion is created when you adopt a broad sloped surface, either the

ground, the top of a cloud layer, or the surface of a glacier, as being level. You think the surface you are flying over is level but it isn’t. It can be encountered when in or recovering from a banked turn or simply by flying over the sloped surface when no other references are available, such as in poor visibility. If no other surrounding references are available, it may be difficult to counter.

4. Illusion of Scale This illusion is created by the lack of reference to objects of known size,

causing you to misjudge an object's actual size or distance. This occurs especially in conditions of poor visibility. Examples are boulders, a single reference landing area surrounded by snow or ice or wires. There may be no solution except to be wary of the circumstances and be cautious.

5. Rate of Closure Illusion The inability to determine rate of closure due to lack of references close to

the helicopter on approach to isolated, topographic features. The usual result is too high in an approach speed. If in doubt, slow down.

6. The Landing Illusion The inability to perceive slope when viewed vertically when landing. This

is not as big a problem when landing on an upslope but on a downslope it can cause you to slightly overshoot your intended landing site and possibly strike the tail on the surface. This can be the result of a poor recce and approach profile. If in doubt, check the slope of the terrain behind you before setting down.

7. Illusion of Motion This illusion is encountered when on approach or landing to a spot when

the surrounding visual references are in motion. Examples are blowing surface snow or dust, landing on or near moving water or causing it to move with rotor wash (water bucketing). On landing look at something that isn't moving. Switching on the landing light to shine through the moving dust or snow to the surface below will help.



5. The Mountain Recce The mountain recce is an information gathering procedure. The primary functions of the mountain recce are to confirm the wind and to allow you the best opportunity to see your proposed landing site at eye level. A recce flight can be either extensive or brief but it is not complete and an approach to land should not be initiated until all relevant information has been obtained. There is no room for unexpected surprises as you are coming out of translation.

Setting Up Your Recce

Estimate the wind enroute to the recce.

Visualize your recce route prior to entering the recce.

Approaching the recce, look for: o slope profiles to indicate demarcation line. o approach and departure routes. o abort and / or overshoot routes. o hazards around the recce route.

Clues That Indicate Wind Direction And Velocity

Helicopter Yaw o with the ball centred, the nose will veer into the wind.

Power changes o to counter updrafts and downdrafts.

Apparent difference in ground speed o while flying both legs of recce at same airspeed.

Fishtailing and sloppy control response o indicate you are downwind.

Turbulence o indicates that you are on the lee side of the terrain

Flying And Information Gathering During the Recce

Recce altitude should be at or slightly above your intended landing site and flown at 60 to 70 MPH.

When possible, recce on the upwind side. Always maintain your drop off, especially if your recce is on the downwind side.

Pass by the landing site at 40 MPH and close enough to get a good look.



Flying And Information Gathering During the Recce (Cont’d)

Look for and confirm the following information: o approach and departure routes o a high, flat spot to land o hazards at the landing site, including slope o a reference point or marker to help find the landing site and land

beside in flat light o wind direction and velocity o demarcation line/turbulence o check altimeter when adjacent the landing site o airspeed versus ground-speed o fishtailing

Once you are past the landing site, look ahead and visualize where you will make your turn.

Maintain your altitude and increase airspeed to 60 to 70 MPH.

Make your turn away from the terrain when possible

Do not lose altitude in the turn (downslope illusion).

Do another pass by the landing site at eye level at 40 MPH.

It is very important to fly the recce with a constant attitude and with as few control inputs as possible in order to best feel the wind.

Important Points for Recce Flights

Wind in the mountains can be extremely variable. This goes for light and variable as well as stronger winds that are gusty.

With light and variable (0-5 knots) conditions, do not be fooled into thinking wind direction is not important. 5 knots in your face versus 5 knots up your butt is a total change of 10 knots. That makes a big difference in how far you can drag out translation on approach.

Be prepared for changes in wind direction; particularly in the last stages of final approach, and before losing translational lift, while you still have some comfortable options.

During final approach prior to losing translational lift is your best opportunity to feel subtle changes and confirm the wind. Also, double-check your selected landing site.

Avoid passing too close to your intended landing site as it passes by too quickly to gather information.

Stay at eye level. Looking down at the landing site makes it difficult to assess slope and surface



Keep turns level at constant altitude. Watch out for illusions doing their magic.

40 mph is a safe recce speed for winds up to 10 knots but you should increase your airspeed if the wind velocity increases.

Keep your indicated airspeed the same for both legs (directions) of your recce to ensure you have the best chance to notice the difference in apparent ground speed.

Always visualize your route and ensure that no hazards interfere with a safe recce flight

Use your altimeter to assist you in staying at the same elevation as the landing site when you are making your turns.

Be aware of the demarcation line, and try to stay on the up flowing air side until you can estimate the amount of turbulence on the downdraft side.

Select the best large landing area just in case of unexpected adverse winds.

Select the approach route with the best abort route options.

6. Operational Hazards (What are the consequences and solutions?) 1. Steep approach angle 2. High rate of descent and low airspeed 3. Vortex ring 4. Hard landings 5. Over torque and over temp 6. Wire strikes 7. Avalanches and cornices 8. Rock slides, falling rock, and falling ice 9. Snags and vets 10. Exceeding VNE


Operational Factors Chapter 3 11. Downwind operations 12. White out 13. Grey out 14. Bad weather route selection 15. Mountain shadows (flying into large areas of shadow – can’t see ahead) 16. Early morning and evening glare 17. Shutting down and parking on the mountain 18. Turning toward the slope instead of away 19. Not crossing ridges at 45 degrees 20. Getting caught between or on top of cloud layers.

21. Not allowing for the lag in control response due to the effects of high density altitude

22. Icing


Part II FLIGHT EXERCISES


MOUNTAIN COURSE FLIGHT TRAINING EXERCISES The Flight Exercises in Part II are laid out in a methodical, easy to understand, format that gives you pertinent information required to learn and fly the exercise. Exercises 1 through 9 cover the basic techniques necessary for safe mountain flying, are progressive and should be completed in sequence. Exercises 10 through 19 allow you to apply and develop your mountain flying skills on various types of mountainous terrain. Your ultimate goal is to be able to correctly assess any situation you are presented with in the mountains and deal with it safely and effectively.

Format Explanation:

Theory Explanation of what we are going to try and accomplish.

Wind, topography, recce, approach routes, etc.

Techniques The sequence of events that you will execute to accomplish

our objective properly and safely. You will have to make notes and drawings from classroom lectures to best understand each exercise.

Hazards, Cautions and Common Errors

Each exercise has similar hazards and also there are hazards that are unique to the specific exercise. Also included are common piloting errors which can lead to hazardous situations.


Flight Exercises

Precision Handling Exercise #1 Confined Areas Exercise #2

Effects of Wind on the Helicopter Exercise #3

Contour Flying Exercise #4

Mountain Recce (figure 8) Exercise #5

Mountain Approach Exercise #6

Mountain Departure Exercise #7

Snow Operations Exercise #8

Mountain Illusions Exercise #9

Ridges Exercise #10

Mountain Tops and Peaks Exercise #11

Wide Saddles Exercise #12

Shoulders Exercise #13

Narrow Saddles Exercise #14

Snowfields and Glaciers Exercise #15

Pinnacles Exercise #16

Cirques Exercise #17

Canyons Exercise #18

Side Hill Landing Pads Exercise #19


Pre Flight Briefing

In the interest of safety and good communication, the following points apply to every flight exercise. When control is passed from the training pilot to the student or vice versus, the words “I have control” or “you have control” must be used. It is important to verbally confirm when you have commenced your approach. Since a mountain approach is often an extension of the recce, the training pilot might not be clear as to when you have started your approach unless you say so. When landing on snow or in areas where there is little visual reference, for training purposes it is important to recce a landing spot where both you and the training pilot will have a reference. Otherwise, the landing might have to be aborted for safety. In the event of a real emergency, the training pilot will take control.


Precision Handling Exercise #1

Theory

This exercise is to allow the Instructor to assess the abilities of the student and to pick out any bad habits that the student may have formed, and to make recommendations to correct them. If you look at the list under techniques, you will get an idea of the things we will be watching. In all cases the less you can move the controls to do the job, the better job you are doing.

Techniques

Departure

Gentle, controlled lift off, to a 1 to 2 foot hover Hover check = 1 - C of G

2 - control response normal 3 - power required

Minimum cyclic inputs Shallow angle minimum power take-off

Approach

Standard approach profile 1-2 foot hover over spot Gentle touch down / spot landing

Exercises

Departures

Approaches

Spot landings

Gentle controlled lift-offs and touch-downs

Constant attitude

Sloping ground

Toe ins


Obstacles on training grounds Density altitude effects on the helicopter Over-controlling


Confined Areas Exercise #2

Theory Confined areas come in all shapes, sizes, and depths. They can be in valley bottoms, up on a mountain top, or on the top edge of a cliff. They might be surrounded by trees but they can also be created by the terrain. Wherever they are, you usually have to look down and in at a sharp angle to gather whatever information you can about where to land. You are probably going to lose translational lift just as you begin your descent on a steep approach, or you will lose it before descending on a vertical approach. You might have to descend into shadows down onto a landing site that is not visible underneath you. Descending below obstacle height, you could enter down flowing air coming over the trees. There are many reasons to make good judgements before committing yourself. At higher elevations confined areas are usually easier to recce, get into, and out of. The trees, if they are even there, are shorter. It is easier to do a close-in recce at eye level. Approaches and departures can be more shallow, however, the landing site might have just as many hazards.

Techniques

Perform an effective recce to include: o wind o route in and out o a landmark reference so you don't lose sight of your landing area o hazards at landing site - such as main rotor, tail rotor, FOD or

blowing snow o consider an overshoot and departure that is not over higher terrain o power available and required for conditions


Difficult to perform proper recce Obstacles on approach Difficulty in selecting level landing site Losing site of confined area location on approach Down flowing air Landing site not visible on descent Main rotor and tail rotor hazards Over loaded for conditions


Effects of Wind on the Helicopter Exercise #3

Theory

During this exercise we will be looking at how the wind affects the helicopter as you manoeuvre or fly through various flight configurations. By experiencing these different effects you will see how the wind will work for you or against you. If you don't pay attention, their effects can be dangerous.

Techniques

In the Hover

Loss of tail rotor authority

Running out of left pedal (simulated)

Aft cyclic limits

Hovering downwind (critical wind azimuth - control and TOT)

Maintaining a constant hover height in gusty conditions

In Flight

Into wind o minimum power requirement o positive feel to helicopter o lower ground speed

Downwind o more power required o fishtailing o higher ground speed

Turns o loss of airspeed and / or altitude while turning downwind at recce

speed

In and Out of Translation

Compare the distance it takes to gain or lose translation with into wind versus downwind conditions


Wind and gusts Landing area and surface Main rotor and tail rotor hazards Downdrafts Over-controlling


Contour Flying Exercise #4

Theory Contour flying is a flight exercise that will utilize your precision handling skills. The goal here is to fly at a predetermined altitude and airspeed, using constant attitude and power management skills. We will use contour flying during training to see how the helicopter reacts to the air as it moves over terrain. Extensive contour flying in the boundary layer is an excellent way to confirm suspected wind velocity. However, it tends to take time and therefore, should be kept to a minimum operationally. Once you are set up on your contour flight path you will adjust power as you fly through updrafts and downdrafts to maintain the same altitude. At 40 mph, if you keep the ball centered, the helicopter will crab into the wind.

Techniques

Approach terrain from the upwind side

Fly at and maintain 40 mph (or Knots)

Attempt to stay in the boundary layer

Maintain constant altitude o power change will indicate updrafts and downdrafts

Keep ball centered o nose will crab into the wind


Strong downdrafts Turbulence Illusions Falling objects from above Not keeping a suitable distance from terrain on inside and outside corners Getting too close horizontally to ground (main rotor strike)


The Mountain Recce (Figure 8) Exercise #5

Theory

The mountain recce is an information gathering procedure. Operationally it can be abbreviated, but you must still be able to gather all pertinent information.

The primary functions of the mountain recce are to confirm the wind and to allow you the best opportunity to see the landing site at eye level. Depending on the landing site you are trying to evaluate, you will often use contour flying techniques at the same time.

Techniques

Visualize recce route prior to entering the recce

Using your estimated wind direction, visualize where you think the Demarcation line will be

Do the recce on the upflow side when possible

Beware of illusions

Attain level flight at eye level with intended landing site, before starting into the actual recce flight (note your altitude)

Constant altitude, attitude, and speed control (40 mph by landing site, 60-70 mph in turns)

Disk loaded up

Confirm the wind o ball centred, nose points into wind o power changes o airspeed versus groundspeed on both legs o fish tailing when downwind

Analyze possible approach and departure routes

Look for suitable landing site (a high, flat spot is best)

When you locate a good landing site, find an obvious reference to guide you back to that general location. If you lose your spot you will have to start over again

Once you are abeam the landing site, turn your attention to the flight route ahead of you, check your altimeter, and do not continue looking back at the landing site (you'll risk losing airspeed)

Visualize ahead where you will make your turns

Make turns into the wind and away from the terrain


Illusions Flying below the demarcation line Losing airspeed on downwind turns Not loading the disk Altitude control


Mountain Approach Exercise #6

Theory

The Mountain Approach is a flat or shallow angled approach that keeps you ahead and / or above the demarcation line. When done correctly, you have a low angle or eye level view of your approaching landing site the disk loaded up and little or zero rate of descent. You are basically following in on the route that you just flew on your recce. Being that it is a flat approach, you must master precision handling, constant attitude control, airspeed control, and spot landings. There is absolutely no room for Flaring on short final. This is the result of poor planning and / or poor judgement. It will require a sudden increase in power and rotor thrust which the engine and rotor system may not be able to supply quickly enough at the altitude you're working at. It can also expose the tail rotor to a possible strike. If you don't have it set up right, abort or overshoot and go around again.

The mountain approach is a follow on to the mountain recce. The recce will give you a good look at your landing site and allowed you to confirm the wind, but it will not let you know what the wind is going to be like at the landing site itself. In most cases you will be landing below the demarcation line so it is important to keep the disk loaded up to more easily react to a wind change or possibly backlash. Remember too that the mountain approach is not the only approach that will work in the mountains. It is a safe and cautious way to approach a spot in the alpine that is completely exposed. When there are any kind of nearby or surrounding obstacles, it might not be possible to do this text book procedure. You must be prepared to modify your approach angle and heading to suit the situation just as you would on an approach to a confined area. The most important aspect of any approach is to properly manage the power you have available. Your approach can be steeper, as long as you load the disk in time, control your rate of descent and maintain your drop off. Maintaining your drop off will, in most cases, be even easier if your approach has to be steeper.

Go to the spot you selected on your recce. Once you're there and you see a better one, then use it. If you overshoot your intended landing spot, don't land long until you confirm you're not trying to land on a downslope - ILLUSIONS.

Techniques

Abort and overshoot routes

Approach must be o constant attitude o little or no rate of descent (if it’s a true mountain approach) o airspeed decreasing o good power management o disc loaded up

Monitor torque and TOT


Confirm wind on final while above translation

Come to hover over spot or no hover landing


Possible wind shift below demarcation line Backlash Loss of tail rotor authority Critical wind azimuth Sloping Ground Tail rotor hazards Illusions Not loading the disc on approach Flaring on short final Overshooting landing spot


Mountain Departure Exercise #7

Theory Most mountain departures, as with mountain approaches, can be accomplished at a shallow angle because the terrain slopes downhill away from you and you don't have to climb over trees or other obstacles. Using a flat or shallow departure angle affords the use of minimum power. This is a useful technique because the OGE power requirements are greater at altitude than at sea level. For example, in standard day conditions with no wind there is sufficient power to hover IGE and OGE at sea level at gross weight. However, at 8000 feet there is sufficient power to hover IGE at gross weight but only enough power to hover OGE if gross weight is reduced by several hundred pounds. Operational gross weights should be reduced as necessary at altitude to account for the loss of OGE hover capability.

Techniques

Select best route . . . . on your recce! Not after your approach!

Gentle lift off over spot to low hover

Check torque reserve

Smooth take-off into wind as conditions permit

Shallow departure angle (requires minimum power)


Backlash Loss of tail rotor authority Critical wind azimuth Insufficient torque in OGE hover


Snow Operations Exercise #8

Theory

Snow conditions are extremely variable. They can vary from slush, hard frozen crust, to a very light powder, and every possibility in between. To prepare yourself for the various types of conditions that you might encounter, your first clue is your outside air temperature gauge. The second clue is knowledge of the weather during the past 24 hours, and the third clue is the conditions that you are observing enroute, such as snow blowing off the ridges and peaks which would indicate powder (cold & dry). The sun shining on the slopes with no wind and an O.A.T. rising above freezing during early afternoon may mean a weak surface crust.

There’s no substitute for experience. Until you have it, be careful in unfamiliar conditions.

In most cases, you will need a reference on the snow's surface to land beside.

Techniques

Perform recce to include: o reference point to land beside o identify what is level and what is sloped

Use landing light in grey out conditions

No hover landing if possible beside reference point - less chance of sideways drift

Tamp helicopter into snow until skids cannot sink any further o favour more nose down attitude to keep tail in the air

Lifting off come straight up o prevent dynamic rollover o ensure clear of surface

Depart with ample skid height above snow


Flat light (grey out) Blowing snow (white out) Crusty (will it hold helicopters’ weight?) Poor reference point at the intended landing site Sloping snow surface (tail or even main rotor hazard) Rocks or tree spikes just under the snow's surface (could cause belly

damage) Air pockets in snow around covered brush, small trees or next to

protruding rock Landing too close to cornices Passenger walking beside skids forming trench, which skids then sink into Main rotor will be closer to disembarking passengers Extreme caution with high skids landing on a crust Dynamic rollover


Mountain Illusions Exercise #9

Theory Mountain illusions are an everyday part of flying in the mountains. Become familiar with them so that you can know when to expect them. Good control of the helicopter in its three axes of movement, pitch, roll, and yaw will help. See chapter 3 for a description of each mountain illusion.

Techniques Identify these illusions by knowing when to expect them:

Up-slope illusion

Down-slope illusion

The broad slope illusion

Illusion of scale

Rate of closure illusion

The landing illusion

Illusion of motion


Tail rotor hazards on landing Dynamic rollover Disorientation Vertigo Flying into the ground! Poor airspeed control (both high and low)


Ridges Exercise #10

Theory Ridges are generally the top of two steep surfaces and present the opportunity for steep demarcation lines in moderate winds. Once again, you need to do a proper analysis of the wind before departing and monitor enroute, to ensure you have the best opportunity for success in landing on narrow ridges. The narrower they get, the less chances are that you are going to find a suitable landing site. Don't hesitate to lighten your load at the base of the ridge in a large alpine meadow and fly up light weight and check it out thoroughly before attempting to land with a heavier load. When crossing a ridge enroute or for the purpose of your recce, do it at a 45o angle at least 100 feet above.

Techniques

Figure 8 recce close in on windward side

Landing site is probably just below demarcation line

Be prepared to use your abort / overshoot route

Prepare for no hover landing


Tail rotor hazards including the slope Main rotor hazards on saw-toothed ridges Steep demarcation line even in light winds Backlash, downdrafts, and turbulence Sloping ground all around Getting below demarcation line while crossing over or landing Doing a steep approach down the demarcation line to the landing

site could result in being suspended or rising with FULL DOWN COLLECTIVE

Landing on Cornices Avoid gross weight operations on a windy day (split your load)


Mountain Tops and Peaks Exercise #11

Theory Most work in the mountains does not involve mountain top landings, but the view is great. A mountain top is a simple feature to work with. By the time you get there you should know the wind's direction and velocity unless it's quite light. The wind can be the strongest wind you'll find anywhere as the mountain sticks up into the prevailing winds. As the wind velocity increases, it also steepens the demarcation line, moves it forward, and increases turbulence. The wind tends to increase in velocity as it goes over the peak, the same as an airfoil. If the wind is light you can do a circle recce, otherwise do a figure 8 recce on the windward side. Illusions will be evident here, so watch your airspeed and altitude. Approach along your recce route. Most often the best place to land is just below the demarcation line so keep the disc loaded, go right to your landing site and be ready for a no hover landing.

Techniques

Circle or figure 8 recce

Select a high, flat spot to land

Flat approach disc loaded

Stay in up flowing air

Fly right to your landing site

Depart into wind


Steep demarcation lines are possible Sloping ground Flat light Illusions – especially rate of closure Cornices Communication sites Cairns. For some reason, people like to build cairns on summits. They can

present an obstacle or a tail rotor hazard.


Wide Saddles Exercise #12

Theory A saddle is like the depression between the two humps on a camel's back. The difference between a wide and a narrow saddle is that a wide saddle has enough room to do your recce on one side of the saddle, whereas with a narrow saddle, you must pass through the saddle to do an effective recce. The problems associated with saddles are mainly related to wind direction and velocity. The reasons should be obvious! Saddles are below the peaks and ridges. This is the environment where downdrafts and turbulence take up residence. Now you will fully understand the importance of studying the wind at all times. The narrower the saddle, the more wind changes you will be exposed to as you make your way along your recce route. For a wide saddle, plan to do your recce on the upwind side. If approaching from the upwind side, do a figure 8 recce. If approaching from the downwind side, cross the saddle into wind at a 45o angle at no less than 100 feet AGL and then do your recce.

Techniques

Recce on upwind side


Sloping ground all around (depending on the width of the saddle) Tail rotor hazards including the slope Cross winds and drift Getting below demarcation line when crossing over the saddle Hard to read demarcation line Illusions – especially upslope and downslope Flat Light on snow Landing on cornices


Shoulders Exercise #13

Theory Alpine shoulders or benches are level areas along a mountain slope. They can vary considerably in size & shape as can the surrounding slope. If there is a shoulder then there might be a steep area somewhere around the shoulder. This can result in a very steep to vertical demarcation line and resulting backlash. Down flowing air is also a strong possibility because this formation will always be attached to higher terrain. If it happens to be on the downwind side of that higher terrain, that’s what you can expect. There are other topographical features that will create backlash, but most are not as innocent looking or as threatening as backlash on a Shoulder.

Techniques

A good recce to identify wind direction and velocity


Sloping ground Backlash Changes in Wind speed and direction


Narrow Saddles Exercise #14

Theory Narrow saddles are not the same as wide ones! Recce technique and wind considerations require a different approach. Think of the Venturi effect. This is what happens with narrow saddles. They are a narrow passage which increases airflow velocity as the air passes through the saddle. Some narrow saddles exist on narrow ridges. In this case, the demarcation line will be steep with an abrupt change to down flowing air. Others can be deep set on wider ridges necessitating an early commitment on your approach. Next time you fly over one, just look at the snow in the saddle to get an idea of the turbulent airflow that can exist. Usually the only place to land is right in the middle of the saddle itself as the surrounding ground is all sloped. One of the main things to remember about narrow saddles is that the wind velocity will be amplified if the wind flows through the saddle or down flowing and turbulent if the wind is strong and aligned with the ridge above.

Techniques

Figure 8 recce right through the saddle

Keep speed up to 60 to 70 MPH on first pass

Decrease speed if wind conditions allow

If you can't decrease your speed then don’t go in there

Approach to land from downwind side


Sloping ground all around Main and Tail rotor hazards because of the slope Crosswinds and drift Backlash, downdrafts, and turbulence Steep demarcation line in narrow set saddles with moderate winds Getting below demarcation line when crossing over the saddle Landing on cornices Avoid gross weight loads on a windy day (split your load)


Snowfields and Glaciers Exercise #15

Theory

Visual reference is the first consideration that should come to mind when planning any mission into these environments.

Snowfields and glaciers present many visual problems. Intense glare, difficulty in detecting gradient, whiteout, lack of depth perception or drifting, blowing snow on the surface. Excellent landing sites are available, but doing your recce and setting up an approach will expose you to becoming disoriented from the lack of reference and various illusions.

Most of the year snowfields and glaciers are covered with fresh white snow. In these conditions you must have bright sunlight shining on the surface you wish to land on otherwise it is impossible to see where the surface is and whether or not you are moving over it. The snow also covers up the crevasses - there might be crevasses hiding beneath the snow – be cautious!! During the late spring and summer the snow and ice become dirty on the surface and bright sunlight is no longer required to attempt a landing. Unless the prevailing winds overpower them, cold katabatic winds flow down hill over the snow and ice. The strongest are on warm sunny afternoons near the toes of glaciers. These winds can be quite shallow or several hundred feet deep. The slope on the snow's surface is difficult to detect. In summer, when the snow melts off, the ice of the glacier is exposed. An exposed glacier can be quite rough. It is often difficult to find a suitable landing site. When you land, the weight of the helicopter will melt the ice under the skids, so ensure you're not parked on too much of a slope. Departures should be made crosswind and cross slope.

Are your passengers familiar with the conditions you are dropping them onto? They should be prepared for the conditions and the hazards.

Techniques

Over snow o select landing site free of crevasses o land facing up the slope

Over ice o select level landing site o ensure no sliding before reducing power o depart across the slope with a headwind component


Lack of visual reference o gradient o white-out o grey out

Illusions Katabatic winds Snow covered crevasses


Pinnacles Exercise #16

Theory

Pinnacles are steep sided protrusions usually standing in isolation to the surrounding topography. The can look inviting from a distance but might not offer anywhere to land.

Pinnacles pose some unique problems. There is generally no reference for closing speed on approach, which exposes you to the illusion that you are hardly moving. Then suddenly, you are arriving way too hot on short final. Once again your precision handling of constant attitude and power management will serve you well. Use the double horizon technique and your altimeter to help your altitude control.

En-route you will be looking for the wind in that location and its effect on the demarcation line on the pinnacle. You will find that the demarcation line is very steep and will almost always result in backlash even if the winds are light (5-10 kts). If the winds are 15 kts or greater it may not be feasible to get onto the pinnacle safely at all – regardless of your gross weight! Also, keep in mind that the pinnacle can be affected by many different types of wind - Valley winds on the lower portion, thermal up flows on the sunny side (Anabatic), down flow boundary wind on the shady side (Katabatic), and prevailing winds at the summit.

This is one of the few mountain features where a circular recce can work well. Some modification of the mountain recce will also work. If it is a truly isolated pinnacle though, you won’t have any reference while flying away from it.

Even if the surface is flat, you probably won’t get much ground effect here because the landing site will be small.

This is not a place where you would want to let the customer intimidate you into landing against your better judgement.

Be familiar with IGE and OGE charts for the pinnacle's elevation and keep your gross weight down.

Techniques

Recce as required (circular or figure 8)

1 or 2 approaches to overshoot may be necessary until you can control your rate of closure


Backlash even in light winds Minimal ground effect Lack of peripheral clues Illusions (especially rate of closure)


Cirques Exercise #17

Theory In the Oxford dictionary, cirque is described as a "natural amphitheatre". This is great as you'll be all the more able to hear your own screams if you neglect proper procedure. This is another topographic example of why understanding the wind is the single most important aspect of Mountain Flying. In light or even moderate winds, cirques aren't usually too much of a problem, but in strong winds it might be better to just stay away. If the prevailing winds are blowing directly into the cirque, the whole cirque will be in up flowing air. If the prevailing winds are from any other direction, at least part of the cirque will be in down flowing air. All cirques are not exactly alike. Their shape is generally the same but Their size and depth can vary considerably. They can be oriented in any direction and the cirque bottom can be quite varied. The walls of a cirque are quite steep so the only place to land is somewhere on the bottom – usually at the outlet or on a bench near the foot of the back wall. If the winds aren't too strong an abbreviated recce can be done in the cirque bottom to select a landing site. This is the most practical method to use. With stronger winds it's best to start with a recce around the rim, then half-way down, then by your intended landing site. Fly around the cirque walls in the boundary layer. If the situation is wild and unpredictable, go somewhere else!

Techniques

Know the strength and direction of the prevailing wind prior to approaching the cirque

Recce cirque bottom for landing site if wind is not too strong

Recce from rim down in stronger winds


Frequent wind changes and turbulence Sloping ground Difficult to get close up view of landing site Finding a good abort / overshoot route when approaching into the cirque Illusions Avoid heavy loads on first trip


Canyons Exercise #18

Theory A canyon is just the opposite of a ridge. A ridge is a narrow piece of ground jutting up into the air with lots of places to go if things don't work out. A canyon on the other hand is a narrow piece of air jutting down into the ground with very few places to go if things don't work out. Just like a confined area in tall trees but with wind thrown in for good measure. The wind can be dead calm, it can blow up the canyon or down or alternately all three if there is a glacier up the valley and it is a hot sunny day. The wind can also be different at the top of the canyon than it is down at the bottom. Warm anabatic winds, cold katabatic winds, and the prevailing wind, all play a part. Obviously a good recce is wise. You might have to commit yourself early depending on the width and depth of the canyon. Recce the top of the canyon to look for a likely landing site on the bottom. Do a low pass down over your intended landing site to check the wind and the landing site. Check vegetation on the canyon walls for wind indications. Sometimes the only possible landing site might be downstream from a waterfall. Be careful, the winds off the waterfall can be quite turbulent.

Techniques

High recce to check wind and possible landing site

Low recce to check wind and confirm landing site

Don't go in too heavy if your overshoot options are limited


Unpredictable winds Narrow canyon walls and leaning trees Debris falling from canyon walls Canyon deeper than expected Poor view of landing site Landing hazards (boulders, sloping ground) Lack of a good drop off or overshoot area


Side Hill Landing Pads Exercise #19

Theory Side hill landing pads can either be natural (a small ledge or shoulder), or man made (a plank or log pad). The natural variety must be recced for a spot to land with consideration to main rotor and tail rotor hazards. The man made variety leave no doubt as to where to land and which way to orient the aircraft. It is best to approach a side hill pad along the slope to allow the maximum drop off and best overshoot. This also helps to avoid a high rate of closure and abrupt flare. Man made pads on clear cuts often blend into the background and become invisible unless they are painted. Use a reference and note your altitude on your first pass. If the wind is moving up the slope you might run out of aft cyclic as you try to land facing the slope, due to increased lift on the horizontal stabilizer and aft portion of the rotor disc. Even with no up-slope wind, re-circulation will cause the helicopter to drift toward the slope. Not a comfortable feeling - use caution!! Many man made pads are elevated requiring OGE hover performance. If the pad hasn't been used in a while, ensure any brush or saplings haven't grown up to create a main rotor or tail rotor hazard. Ensure that plank pads are sound and nailed down. They are not always level! Log pads can only be landed on with the skids perpendicular to the logs. Most can only be landed on one way. Usually with the nose of the helicopter pointed toward the hill or with the tail on the least hazardous side. Before landing, ensure the logs aren't rotten (be suspicious of a pad more than 2 years old), that the logs are secured, and the pad is in useable condition. If the pad is newly built or currently in use, such as in a heli-logging operation, it must be checked for hazards every time you use it. If possible approach it at eye level. Check the following on a new pad:

Is it going to fall over when you land on it?

Is it level, fore, aft, and sideways?

Are the tops of all the logs at the same height?

Are there any knots sticking up?

Is it big enough for your helicopter?

Will there be enough main rotor and tail rotor clearance for your helicopter?

Will any debris or branches blow up into the rotors when you land?


Check the following on a pad currently in use, again approach it at eye level, if possible:

Is there any logging close to or up hill from the pad?

Are there any branches or other debris either on, around, or above the pad that may be a hazard to either the main rotor or tail rotor?

Has the pad been damaged or moved?

Is it level?

Is it big enough for your helicopter?

Log pads are, at best, a temporary landing site that should be used with maximum caution.

Techniques

Recce as required

Approach parallel the slope

Approach pad at eye level, if possible

Beware of updrafts, down drafts and hazards around pad


Pad might not be level Main rotor hazard against hill Updrafts and re-circulation (might run out of aft cyclic travel) OGE hover performance may be required Loss of tail rotor authority Integrity of landing pad Invisibility of landing pad


Standing Timber Heli-pads

Hillside Logging Style Helipad


Hillside Logging Style Helipad


Appendices

1. Density Altitude Chart Equivalent Wind Chill Chart 2. 206 Airspeed Limitations 3. 206 Hover Ceiling IN Ground Effect 4. 206 Hover Ceiling OUT OF Ground Effect 5. 206 Flight Crew Limitations (slinging) 6. 206 Max Payload Table (using Jet A) 7. 206 Max Payload Table (using Jet B) 8. 206 Baggage Compartment Loading Chart 9. 206 Power Check Chart (particle separator installed) 10. Loss of tail rotor authority article 11. 206 Critical Relative Wind Azimuth Area 12. High Flight by John Magee


Appendix # 1


Appendix # 2


Appendix # 3

The following information also applies to Appendix #4


Appendix # 3


Appendix # 4

See first page of Appendix #3 for definition of Area “A” and “B”


Appendix # 5


Appendix # 6


Appendix # 7


Appendix # 8


Appendix # 9


Appendix # 10


Appendix # 10 -2-


Appendix # 10 -3-


Appendix # 10 -4-


Appendix # 11


Appendix # 12

High Flight

by John Magee Oh, I have slipped the surly bonds of earth And danced the skies on laughter-silvered wings, Sunward I've climbed and joined the tumbling mirth Of sun-split clouds . . . . . and done a hundred things You have not dreamed of . . . . . wheeled and soared and swung, High in the sunlit silence. Hovering there I've chased the shouting wind along and flung My eager craft through footless halls of air Up, up the long delirious, burning blue I've topped the windswept heights with easy grace Where never lark, or even eagle flew And, while with silent, lifting mind I've trod The high un-trespassed sanctity of space,

Put out my hand, and touched the face of God This poem was written by an American, Lt. John Magee, who joined the Royal Canadian Airforce, as a volunteer in 1940. He was killed in action over England 18 months later. He was just 19. It was the only poem he ever wrote.

VIH Helicopter Mountain Flying Manual

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