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Human Factors: Vision, Scanning, and Judgement

Eyes provide the brain with a visual image of the environment. Each eye acts as a natural and very sophisticated digital camera. Its basic function is to collect light rays reflected from an object, using the lens to focus these rays into an image on a screen (the retina), and then converting this image into electrical signals that are sent via the optic nerve to the brain. This is how you see. The brain matches the image to previously stored data so you recognize (perceive) the object. The connection of the optic nerve to the brain is so close and integral, and the importance of the messages sent to the brain is so dominant, that the eyes can almost be considered an extension of the brain. Today we’ll talk more about vision with an excerpt from our textbook The Pilot’s Manual Volume 2: Ground School (PM-2C).
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Scanning by Day
The central (foveal) region of the retina provides the best vision, and in full color but only during reasonable daylight. Objects are best seen by day if you can focus their image on the foveal region, and you do this by looking directly at them. The most effective method of scanning for other aircraft for collision avoidance during daylight hours is to use a series of short, regularly spaced eye movements to search each 10° sector of the sky. Systematically focusing on different segments of the sky for short intervals is a better technique than continuously sweeping the sky. This is sometimes called the saccade/fixation cycle, where the saccade or movement takes about one-third of a second.

Methodical scan.

Methodical scan.

Relative Movement
If there is no apparent relative motion between you and another aircraft, you may be on a collision course, especially if the other aircraft appears to be getting bigger and bigger in the windshield. Due to the lack of movement across your windshield, an aircraft on a collision course with you will be more difficult to spot than one that is not on a collision course.

Any relative movement of an object against its background usually makes it easier to notice in your peripheral vision. The image of the other aircraft may not increase in size much at first, but, shortly before impact, it would rapidly increase in size. The time available for you to avoid a collision may be quite brief, depending upon when you see the other aircraft and the rate of closure.

Constant relative position = collision course.

Constant relative position = collision course.

If you are flying at 100 knots and it is flying at 500 knots in the opposite direction, the rate of closure is 600 knots, i.e. ten nautical miles per minute. If you spot the other aircraft at a distance of one nautical mile, you only have 1/10 of a minute (six seconds) to potential impact. If you are a vigilant pilot and spot it at 3 nautical miles you have eighteen seconds in which to act.

In hazy or low-visibility conditions, your ability to see other aircraft and objects with edges that might be blurred will be diminished and, if you can see them, they may appear to be further away than their actual distance. You might be closer than you think.

Empty-Field Myopia
When trying to search for other aircraft in an empty sky, the natural tendency of a resting eye is to focus at about six feet. Consequently, distant aircraft may not be noticed. To avoid this empty-field myopia, you should focus on any available distant object, such as a cloud or a landmark, to lengthen your focus. If the sky is empty of clouds or other objects, then focus briefly on a relatively distant part of the airplane like a wing tip as a means of lengthening your focus. Having spotted an airplane in an otherwise empty sky, be aware that it could be closer to you than it appears to be, because you have no other object with which to compare its size.

Specks
A small, dark image formed on the retina could be a distant aircraft, or it could be a speck of dirt or dust, or an insect spot, on the windshield. Specks, dust particles, a scratch, or an insect on the windshield might be mistaken for a distant airplane. Simply moving your head will allow you to discriminate between marks on the windshield and distant objects.

Specks?

Specks?

Scanning by Night
The central (foveal) region of the retina containing mainly cones is not as effective at night, causing an area of reduced visual sensitivity in your central vision. Peripheral vision, provided by the rods in the outer band of the retina, is more effective albeit color blind. An object at night is more readily visible when you are looking to the side of it by ten or twenty degrees, rather than directly at it. Color is not perceived by the rods, and so your night vision will be in shades of gray. Objects will not be as sharply defined (focused) as in daytime foveal vision.

The most effective way to use your eyes during night flight is to scan small sectors of sky more slowly than in daylight to permit off-center viewing of objects in your peripheral vision, and to deliberately focus your perception (mind) a few degrees from your visual center of attention (that is, look at a point but look for objects around it). Since you may not be able to see the aircraft shape at night, you will have to determine its direction of travel making use of its visible lighting:

  • the flashing red beacon;
  • the red navigation light on the left wing tip;
  • the green navigation light on the right wing tip; and
  • a steady white light on the tail.
Position lights.

Position lights.

Visual Judgment on Approach
The eyes and brain use many clues and stored images of known objects to help in judging distance, size and height. The relative size and relative clarity of objects give clues to their relative distances: a bigger object is assumed to be nearer than a smaller one and a more clearly defined object nearer than a blurry one. When the object is near, binocular vision (the slightly different images of a nearby object relative to its background seen by each eye) assists in depth perception.

Texture also assists in depth perception: the more visible the texture, the closer the object appears to be. On final approach as you near the aim point, the surface texture will appear to flow outward in all directions from the point on which you are focused. This is one means by which you can visually maintain the flight path to the aim point: adjust the attitude and heading so that the point from which the texture appears to be moving outward remains the desired aim point.

Aim point.

Aim point.

Texture is also used for the estimation of height; for instance, as you approach flare height for a landing, the actual texture of the runway or the grass passing by the cockpit becomes increasingly noticeable. Relative motion also aids in depth perception. Near objects generally appear to pass by faster than more distant objects. This helps a visual pilot estimate height above the runway before and during the flare: the closer the airplane is to the runway, the faster the runway surface and the surrounding environment appears to pass by.

Depth perception can be difficult in hazy or misty conditions, where edges are blurred, colors are muted, and light rays may be refracted unusually. This gives the impression of greater distance, an impression reinforced by the fact that we often have to look at distant objects through a smoggy or hazy atmosphere. This illusion is referred to as environmental perspective. In hazy conditions, the object might be closer than it seems; in very clear conditions, the object might be further away than it seems. On hazy days, you might touch down earlier than expected; on very clear nights, you might flare a little too soon.

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CFI Brief: Pilot Deviations, Stay Alert!

Yesterday, the FAA Safety Team distributed a newly published Fly Safe Fact Sheet, Avoiding Pilot Deviations (PDs). Now listen, if you’ve read this blog over the years you know we have discussed this topic before. However, it’s worth discussing on the regular since PDs can lead to serious consequences in the form of accidents or enforcement violations.

If you are not already familiar with what a pilot deviation is, it is defined as an action of a pilot that violates any Federal Aviation Regulation. While PDs should be avoided, the regulations do authorize deviations from a clearance in response to a traffic alert and collision avoidance system resolution advisory. Meaning, if a possible collision with another aircraft or vehicle is imminent it is OK to deviate. You must however notify ATC as soon as possible following a deviation.

Piot deviations are broken down into two separate categories, airborne and ground. Airborne deviations result when a pilot strays from an assigned heading or altitude or from an instrument procedure, or if the pilot penetrates controlled or restricted airspace without ATC clearance. Ground deviations (also called surface deviations) include taxiing, taking off, or landing without clearance, deviating from an assigned taxi route, or failing to hold short of an assigned clearance limit.

Ways to Avoid Pilot Deviations:

Plan each flight —you may have flown the flight many times before but conditions and situations can change rapidly, such as in the case of a pop-up temporary flight restriction (TFR). Take a few minutes prior to each flight to plan accordingly.

Talk and squawk —Proper communication with ATC has its benefits. Flight following often makes the controller’s job easier because they can better integrate VFR and IFR traffic.

Give yourself some room —GPS is usually more precise than ATC radar. Using your GPS to fly up to and along the line of the airspace you are trying to avoid could result in a pilot deviation because ATC radar may show you within the restricted airspace.

Stay Alert – This is often overlooked during ground operations. It’s important that whether you are in the air or on the ground you maintain focus and alertness at all times. Keep your head out of the cockpit and on a swivel.

Click the below image to access the FAA Fact Sheet and see the full text on the 4 steps to avoid pilot deviations.

RunwaySafety_24x18_21A

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Weather: Precipitation

We’re seeing rain for the first time in over two months in the Seattle area right now, so how about a refresher on precipitation today on the Learn to Fly Blog? Today’s post is excerpted from Aviation Weather (AC 00-6B).

Precipitation is any of the forms of water particles, whether liquid or solid, that fall from the atmosphere and reach the ground. The precipitation types are: drizzle, rain, snow, snow grains, ice crystals, ice pellets, hail, and small hail and/or snow pellets.

Precipitation formation requires three ingredients: water vapor, sufficient lift to condense the water vapor into clouds, and a growth process that allows cloud droplets to grow large and heavy enough to fall as precipitation. Significant precipitation usually requires clouds to be at least 4,000 feet thick. The heavier the precipitation, the thicker the clouds are likely to be. When arriving or departing from an airport reporting precipitation of light or greater intensity, expect clouds to be more than 4,000 feet thick.

All clouds contain water, but only some produce precipitation. This is because cloud droplets and/or ice crystals are too small and light to fall to the ground as precipitation. Because of their microscopic size, the rate at which cloud droplets fall is incredibly slow. An average cloud droplet falling from a cloud base at 3,300 feet (1,000 meters) would require about 48 hours to reach the ground. It would never complete this journey because it would evaporate within minutes after falling below the cloud base. Two growth processes exist which allow cloud droplets (or ice crystals) to grow large enough to reach the ground as precipitation before they evaporate (or sublimate). One process is called the collision-coalescence, or warm rain process (see Figure 14-1). In this process, collisions occur between cloud droplets of varying size and different fall speeds, sticking together or coalescing to form larger drops. Finally, the drops become too large to be suspended in the air, and they fall to the ground as rain. This is thought to be the primary growth process in warm, tropical air masses where the freezing level is very high.
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Figure 14-1. The collision-coalescence or warm rain process. Most cloud droplets are too small and light to fall to the ground as precipitation. However, the larger cloud droplets fall more rapidly and are able to sweep up the smaller ones in their path and grow.

The other process is the ice crystal process. This occurs in colder clouds when both ice crystals and water droplets are present. In this situation, it is easier for water vapor to deposit directly onto the ice crystals so the ice crystals grow at the expense of the water droplets. The crystals eventually become heavy enough to fall. If it is cold near the surface, it may snow; otherwise, the snowflakes may melt to rain. This is thought to be the primary growth process in mid- and high-latitudes.

The vertical distribution of temperature will often determine the type of precipitation that occurs at the surface. Snow occurs when the temperature remains below freezing throughout the entire depth of the atmosphere (see Figure 14-2).
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Figure 14-2. Snow temperature environment.

Ice pellets (sleet) occur when there is a shallow layer aloft with above freezing temperatures and with a deep layer of below freezing air based at the surface. As snow falls into the shallow warm layer, the snowflakes partially melt. As the precipitation reenters air that is below freezing, it refreezes into ice pellets (see Figure 14-3).
00-6b_14-3
Figure 14-3. Ice pellets temperature environment.

Freezing rain occurs when there is a deep layer aloft with above freezing temperatures and with a shallow layer of below freezing air at the surface. It can begin as either rain and/or snow, but becomes all rain in the warm layer. The rain falls back into below freezing air, but since the depth is shallow, the rain does not have time to freeze into ice pellets (see Figure 14-4). The drops freeze on contact with the ground or exposed objects.
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Figure 14-4. Freezing rain temperature environment.

Rain occurs when there is a deep layer of above freezing air based at the surface (see Figure 14-5).
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Figure 14-5. Rain temperature environment.

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Aerodynamics: Descent and Gliding Flight

Our CFI is out enjoying the Reno Air Races this week, so today we’ll share a follow up to Monday’s post with another excerpt from Aerodynamics for Aviators.

Descending a light propeller-driven general aviation aircraft is a fairly simple task. Reduce power to a point where there is more power required than power available, and the basic principle of weight takes over. Under normal flight conditions, descending flight is initiated by the pilot creating a decrement of power (more power required than available). Once the aircraft begins descending, the weight vector can be broken up into two parts, just like with the climb. One component acts perpendicular to the flightpath (down), the other acts forward and parallel to the flightpath, helping accelerate the aircraft.

Gliding flight can be self-induced by bringing the power back to idle, but in most piston aircraft, descents are not conducted at idle power, thus they are called a powered descent. This is because of shock cooling and the possible damage it could cause to the engine. A true gliding descent would be used if the engine fails. Gliding flight can be broken down into two parts, minimum sink and maximum range.

The minimum sink glide is used to prolong the time aloft in the event the engine or engines fail. This is a speed that is not published, but could be useful if you are over your current landing site and wish to stay aloft a little longer. Most light single-engine airplanes will be at (or close to) minimum sink with full aft trim. This is slower than best glide speed. A pilot who elects to use this method should accelerate to best glide once a normal pattern altitude is reached. This will provide a larger margin above stall and the aircraft will have more positive maneuverability. It should be noted that the best glide speed should be used unless the pilot has training and experience flying at the minimum sink glide speed.

The maximum glide range occurs at the speed for maximum range: L/DMAX. This is generally a published speed and is used when the engine stops or fails in flight. Some Airplane Flying Manuals (AFMs) contain glide ratio charts. There are some concerns with these charts:

  1. They do not account for wind.
  2. They are usually calculated in a minimum drag configuration (gear and flaps up).
  3. They are usually calculated with controllable-pitch propellers in the full decrease position (high AOA).
  4. They are usually calculated at maximum gross weight.

Wind is a factor in glide distance and angle. A headwind will decrease glide distance, and the angle of descent will increase (steepen). A tailwind will increase the glide distance and flatten the angle of descent. You experience the effects of both a headwind and a tailwind when you do a power-off approach. On downwind the aircraft has a flatter descent and a higher groundspeed. Turning base to final, the angle of descent steepens and the groundspeed slows.

Weight is also a factor in glide distance if L/DMAX is not maintained. Without an AOA indicator, the only way to maintain a specific AOA at L/DMAX is to vary the airspeed. As weight increases, the airspeed would need to be increased to maintain L/DMAX.

Altitude also affects the airplane’s gliding distance. To understand this we need to step back and look at the effects of altitude on true airspeed. As the aircraft climbs, TAS increases about 2% per 1,000 feet. An aircraft gliding at higher altitudes will have a higher TAS, this means that it will be moving down the slope at a faster rate. This is of particular importance when operating an aircraft at high density altitudes.

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Aerodynamics: Cruise Flight

Cruise flight centers on two basic principles: how far we can fly, and for how long. How far we can fly is defined as the aircraft’s range. How long we can fly is defined as endurance. Today’s post is an excerpt from our textbook Aerodynamics for Aviators.

When flying, we generally consider range in two ways:

  1. Maximizing the distance we fly for a given fuel load.
  2. Traveling a specified distance while burning minimum fuel.

Endurance
It’s important to understand that range and endurance are not the same. Range relates to distance, endurance relates to time. The formula for endurance is:

endurance = hours ÷ fuel

Hours is simply flight time expressed in whatever units you want: hours, minutes or seconds. Fuel can be expressed in gallons or pounds. A pilot who wants to achieve maximum endurance would slow the aircraft to the minimum power required speed. Figure 5-24 shows the minimum power point being the lowest point in the drag curve.

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Figure 5-24. Maximum endurance.

If the aircraft were to slow even further, to point A, drag would increase rapidly, more power would be required, and the engine would burn more fuel. If the aircraft were to accelerate above point B, drag also increases, which increases fuel burn. As you can see, flying at maximum endurance speed is not practical in the real world; you may save fuel but it would take forever to get to the destination. This speed is also not practical for operations such as holding because it is generally close to stall. From a practical standpoint, endurance comes from the selection of a cruise power setting of 55%, 65%, or 75% endurance charts. The point of this type of flying is generally to minimize or eliminate fuel stops (very time consuming) along the route, or to minimize fuel burn for cost purposes—not necessarily to stay aloft for hours on end.

Range
Range can be broken down into two parts: specific range and total range. An easy way to understand the difference is to use a car trip scenario. If I have a car that has a 20 gallon fuel tank and gets 30 miles per gallon, I can travel 600 miles on one tank of gas. The specific range in this example is 30 miles per gallon, and the total range is 600 miles. In an airplane, specific range is how many nautical miles you can travel on one gallon or pound of fuel. The total range is how far the airplane can fly with the remaining fuel load on board the aircraft. The definition for specific range is:

specific range = NM ÷ gallons of fuel (Note: pounds can be inserted for gallons.)

Specific range is affected by three things: (1) aircraft weight, (2) altitude, and (3) configuration. The maximum range of the aircraft can be found at L/DMAX. Unlike endurance, which is found on the drag curve where minimum power is required, maximum range is found where the ratio of speed to power required is the greatest. This is located on the graph by drawing a tangent line from the origin to the power required curve (Figure 5-24). Another way to think about this is that as you move from the origin point along the tangent line toward L/DMAX you increase airspeed at a greater rate than fuel burn (think of the ratio). At L/DMAX, the ratio of fuel to airspeed should be 1. At any speed above L/DMAX, the fuel burn ratio increases at a greater rate than the airspeed. Therefore, L/DMAX is the point where the speed-to-power ratio required is the greatest.

Another aspect of range that we need to examine is the effect of weight on range. Because L/DMAX occurs at a specific angle of attack, and most general aviation airplanes do not have AOA indicators, the airspeed has to be varied as weight changes to maintain a constant AOA. Figure 5-25 illustrates this: as weight increases, the speed must be increased to maintain the AOA. This is because as weight is increased, the AOA must be increased to produce more lift; the only way to lower the AOA is to increase speed. As weight decreases, the speed must decrease. The reasoning is that as the aircraft becomes lighter, the AOA is lowered to compensate for less weight; the only way to increase AOA is to reduce speed (Figure 5-25).

5-25

Figure 5-25. The effect of weight on range.

The effect of altitude on range can be seen in Figure 5-26. Flights operating at high altitude require a higher TAS, which will require more power.

5-26

Figure 5-26. The effect of altitude on range.

Another aspect of cruise flight relating to range and endurance, one that is often not talked about in textbooks, is cruise performance. From a practical standpoint, the pilot will not fly the aircraft at maximum endurance or range—it is just too slow. In reality, pilots often operate propeller-driven airplanes at 55%, 65%, or 75% best power or endurance.

In order to calculate how to get to your destination as fast as possible, find the highest true airspeed for your aircraft. Most fixed-gear single-engine aircraft that cruise in the 110–130 knot range will have their highest TAS in the 6,000 to 7,000-foot range. This is a good place to start; however, the wind, terrain, and the need for fuel stops will dictate the altitude and speed at which the aircraft ultimately flies.

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CFI Brief: What is Aeronautical Decision Making?

Aeronautical decision making (ADM) is a systematic approach to the mental process used by aircraft pilots to consistently determine the best course of action in response to a given set of circumstances. ADM is vital process allowing pilots to safely and efficiently manage risk. Although there is no way to eliminate the associated risks and hazards that come with aviation the proper application of ADM will allow the pilot to limit exposure to risks and hazards.

Risk Management is the part of the decision making process which relies on situational awareness, problem recognition, and good judgment to reduce risks associated with each flight.

The ADM process addresses all aspects of decision making in the cockpit and identifies the steps involved in good decision making. Steps for good decision making are:

  1. Identifying personal attitudes hazardous to safe flight.
  2. Learning behavior modification techniques.
  3. Learning how to recognize and cope with stress.
  4. Developing risk assessment skills.
  5. Using all resources in a multicrew situation.
  6. Evaluating the effectiveness of one’s ADM skills.

There are a number of classic behavioral traps into which pilots have been known to fall. Pilots, particularly those with considerable experience, as a rule always try to complete a flight as planned, please passengers, meet schedules, and generally demonstrate that they have the “right stuff.” These tendencies ultimately may lead to practices that are dangerous and often illegal, and may lead to a mishap. All experienced pilots have fallen prey to, or have been tempted by, one or more of these tendencies in their flying careers. These dangerous tendencies or behavior patterns, which must be identified and eliminated, include:

Peer Pressure. Poor decision making based upon emotional response to peers rather than evaluating a situation objectively.

Mind Set. The inability to recognize and cope with changes in the situation different from those anticipated or planned.

Get-There-Itis. This tendency, common among pilots, clouds the vision and impairs judgment by causing a fixation on the original goal or destination combined with a total disregard for any alternative course of action.

Duck-Under Syndrome. The tendency to sneak a peek by descending below minimums during an approach. Based on a belief that there is always a built-in “fudge” factor that can be used or on an unwillingness to admit defeat and shoot a missed approach.

Scud Running. Pushing the capabilities of the pilot and the aircraft to the limits by trying to maintain visual contact with the terrain while trying to avoid physical contact with it. This attitude is characterized by the old pilot’s joke: “If it’s too bad to go IFR, we’ll go VFR.”

Continuing Visual Flight Rules (VFR) into instrument conditions often leads to spatial disorientation or collision with ground/obstacles. It is even more dangerous if the pilot is not instrument qualified or current.

Getting Behind the Aircraft. Allowing events or the situation to control your actions rather than the other way around. Characterized by a constant state of surprise at what happens next.

Loss of Positional or Situation Awareness. Another case of getting behind the aircraft which results in not knowing where you are, an inability to recognize deteriorating circumstances, and/or the misjudgment of the rate of deterioration.

Operating Without Adequate Fuel Reserves. Ignoring minimum fuel reserve requirements, either VFR or Instrument Flight Rules (IFR), is generally the result of overconfidence, lack of flight planning, or ignoring the regulations.

Descent Below the Minimum Enroute Altitude. The duck-under syndrome (mentioned above) manifesting itself during the enroute portion of an IFR flight.

Flying Outside the Envelope. Unjustified reliance on the (usually mistaken) belief that the aircraft’s high performance capability meets the demands imposed by the pilot’s (usually overestimated) flying skills.

Neglect of Flight Planning, Preflight Inspections, Checklists, Etc. Unjustified reliance on the pilot’s short and long term memory, regular flying skills, repetitive and familiar routes, etc.

Each ADM student should take the Self-Assessment Hazardous Attitude Inventory Test in order to gain a realistic perspective on his/her attitudes toward flying. The inventory test requires the pilot to provide a response which most accurately reflects the reasoning behind his/her decision. The pilot must choose one of the five given reasons for making that decision, even though the pilot may not consider any of the five choices acceptable. The inventory test presents extreme cases of incorrect pilot decision making in an effort to introduce the five types of hazardous attitudes.

ADM addresses the following five hazardous attitudes:

  1. Antiauthority (don’t tell me!). This attitude is found in people who do not like anyone telling them what to do. In a sense they are saying “no one can tell me what to do.” They may be resentful of having someone tell them what to do or may regard rules, regulations, and procedures as silly or unnecessary. However, it is always your prerogative to question authority if you feel it is in error. The antidote for this attitude is: Follow the rules. They are usually right.
  2. Impulsivity (do something quickly!) is the attitude of people who frequently feel the need to do something—anything—immediately. They do not stop to think about what they are about to do, they do not select the best alternative, and they do the first thing that comes to mind. The antidote for this attitude is: Not so fast. Think first.
  3. Invulnerability (it won’t happen to me). Many people feel that accidents happen to others, but never to them. They know accidents can happen, and they know that anyone can be affected. They never really feel or believe that they will be personally involved. Pilots who think this way are more likely to take chances and increase risk. The antidote for this attitude is: It could happen to me.
  4. Macho (I can do it). Pilots who are always trying to prove that they are better than anyone else are thinking “I can do it—I’ll show them.” Pilots with this type of attitude will try to prove themselves by taking risks in order to impress others. While this pattern is thought to be a male characteristic, women are equally susceptible. The antidote for this attitude is: taking chances is foolish.
  5. Resignation (what’s the use?). Pilots who think “what’s the use?” do not see themselves as being able to make a great deal of difference in what happens to them. When things go well, the pilot is apt to think that’s good luck. When things go badly, the pilot may feel that “someone is out to get me,” or attribute it to bad luck. The pilot will leave the action to others, for better or worse. Sometimes, such pilots will even go along with unreasonable requests just to be a “nice guy.” The antidote for this attitude is: I’m not helpless. I can make a difference.

Hazardous attitudes which contribute to poor pilot judgment can be effectively counteracted by redirecting that hazardous attitude so that appropriate action can be taken. Recognition of hazardous thoughts is the first step in neutralizing them in the ADM process. Pilots should become familiar with a means of counteracting hazardous attitudes with an appropriate antidote thought. When a pilot recognizes a thought as hazardous, the pilot should label that thought as hazardous, then correct that thought by stating the corresponding antidote.

If you hope to succeed at reducing stress associated with crisis management in the air or with your job, it is essential to begin by making a personal assessment of stress in all areas of your life. Good cockpit stress management begins with good life stress management. Many of the stress coping techniques practiced for life stress management are not usually practical in flight. Rather, you must condition yourself to relax and think rationally when stress appears. The following checklist outlines some thoughts on cockpit stress management.

  1. Avoid situations that distract you from flying the aircraft.
  2. Reduce your workload to reduce stress levels. This will create a proper environment in which to make good decisions.
  3. If an emergency does occur, be calm. Think for a moment, weigh the alternatives, then act.
  4. Maintain proficiency in your aircraft; proficiency builds confidence. Familiarize yourself thoroughly with your aircraft, its systems, and emergency procedures.
  5. Know and respect your own personal limits.
  6. Do not let little mistakes bother you until they build into a big thing. Wait until after you land, then “debrief” and analyze past actions.
  7. If flying is adding to your stress, either stop flying or seek professional help to manage your stress within acceptable limits.

The DECIDE Model, comprised of a six-step process, is intended to provide the pilot with a logical way of approaching decision making. The six elements of the DECIDE Model represent a continuous loop decision process which can be used to assist a pilot in the decision making process when he/she is faced with a change in a situation that requires a judgment. This DECIDE Model is primarily focused on the intellectual component, but can have an impact on the motivational component of judgment as well. If a pilot practices the DECIDE Model in all decision making, its use can become very natural and could result in better decisions being made under all types of situations.

  1. Detect. The decisionmaker detects the fact that change has occurred.
  2. Estimate. The decisionmaker estimates the need to counter or react to the change.
  3. Choose. The decisionmaker chooses a desirable outcome (in terms of success) for the flight.
  4. Identify. The decisionmaker identifies actions which could successfully control the change.
  5. Do. The decisionmaker takes the necessary action.
  6. Evaluate. The decisionmaker evaluates the effect(s) of his/her action countering the change.

 

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CFI Brief: Would I be a good flight instructor?

Have you ever thought about taking you’re flying career to the next level and becoming a Certified Flight Instructor?  Well, today we are going to take a quick look at some of the characteristics and responsibilities that and aviation instructor must possess. Many students view an aviation instructor as an authority, so it is important for an instructor to project a knowledgeable and professional image at all times.

One of the responsibilities of a good flight instructor is maintaining a high level of professionalism, which relates directly to the instructor’s public image. Characteristics of an instructor’s professionalism include:

  1. Sincerity. Any facade of instructor pretentiousness, whether it be real or mistakenly assumed by the student, will immediately cause the student to lose confidence in the instructor, and little learning will be accomplished. Anything less than sincere performance destroys the effectiveness of the professional instructor.
  1. Acceptance of the student. The professional relationship between the instructor and the student should be based on a mutual acknowledgment that both the student and the instructor are important to each other, and both are working toward the same objectives. Under no circumstances should an instructor do anything which implies degradation of the student.
  1. Personal appearance and habits. A flight instructor who is rude, thoughtless, and inattentive cannot hold the respect of the students, regardless of his/her piloting ability.
  1. Demeanor. The instructor should avoid erratic movements, distracting speech habits, and capricious changes in mood.
  1. Safety practices and accident prevention. A flight instructor must meticulously observe all regulations and recognized safety practices during all flight operations.
  1. Proper language. The use of profanity and obscene language leads to distrust, or at best, to a lack of complete confidence.
  1. Self-improvement. Professional flight instructors must never become complacent or satisfied with their own qualifications and ability.

As a flight instructor you will want to strive daily to practice the items in the “Instructor Do’s” list , and do your best to stay away from the “Instructor Don’ts” list. From the Aviation Instructors Handbook (FAA-H-8083-9A):

CFI Do & Donts

One “don’t” to make mention of; personal hygiene goes both ways. Nothing’s worse then a couple people stuck in a small plane who haven’t showered!

An aviation instructor must also be self-aware of numerous responsibilities. There are five main responsibilities of an aviation instructor.

  1. Helping students learn.
  2. Providing adequate instruction.
  3. Demanding adequate standards of performance.
  4. Emphasizing the positive.
  5. Ensuring aviation safety.

To be an effective instructor you will need to maintain a high level of student motivation by making each lesson a pleasurable experience. It’s important to realize that people are not always attracted to something because it is easy. Most will put forth the required effort to produce rewards such as self-enhancement and personal satisfaction.

As an instructor you should make learning to fly interesting by keeping the students apprised of the course and lesson objectives. Not knowing the objectives leads the student to confusion, disinterest, and uneasiness. Instead instructors should guide their students in exploration and experimentation, to help them develop their own capabilities and self-confidence.

For instruction to produce the desired results, instructors must carefully and correctly analyze the personality, thinking, and ability of each student. Students who have been incorrectly analyzed as slow thinkers may actually be quick thinkers, but act slowly or at the wrong time because of lack of confidence. Slow students can often be helped by assigning sub goals which are more easily attainable than the normal learning goals. This allows the student to practice elements of the task as confidence and ability grows.

Apt students also create problems. Because they make less mistakes, they may assume that the correction of errors is unimportant. Such overconfidence results in faulty performance. A good instructor will constantly raise the standard of performance demanded of apt students and will demand greater effort.

Flight instructors fail to provide competent instruction when they permit their students to get by with a substandard performance, or without learning thoroughly some item of knowledge pertinent to safe piloting. The positive approach to flight instruction points out to the student the pleasurable features of aviation before the unpleasant possibilities are discussed. One example of a positive approach is to include a normal round-trip flight to a nearby airport on the first instructional flight.

Anxiety, or fear, is probably the most significant psychological factor affecting flight instruction. The responses to anxiety vary greatly, ranging from hesitancy to act, to the impulse “to do something even if it’s wrong.” Some students may freeze in place and do nothing, while others may do unusual things without rational thought or reason. Normal reaction to anxiety can be countered by reinforcing the student’s enjoyment of flying, and by teaching them to treat fear as a normal reaction rather than ignoring it. Normal individuals react to stress by responding rapidly and exactly, within the limits of their experience and training. Abnormal reactions to stress are evidenced by:

  • Autonomic responses, such as sweating, rapid heart rate, paleness, etc.
  • Inappropriate reactions, such as extreme overcooperation, painstaking self-control; inappropriate laughter or singing, very rapid changes in emotions, and motion sickness under stress
  • Marked changes in mood on different lessons, such as excellent morale followed by deep depressio
  • Severe anger at the flight instructor, service personnel, or others.

So you think you have what it takes to take the next step in your flying career? Instructing can be an extremely fun and rewarding experience for any aviator. The majority of the information discussed above is all available in the Aviation Instructors Handbook (FAA-H-8083-9A). The information contained in this book will be required knowledge for anyone wishing to obtain a flight or ground instructor certificate. I would also encourage you to check out The Flight Instructor Survival Guide by Arlynn McMahon. It’s an insightful, funny at times and enjoyable read. Also a great present for your instructor (hint, hint)!
CFI-SG_Web

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Aircraft Performance: Changing Airspeed in Straight-and-Level Flight

Normal cruise involves setting cruise power, holding cruise altitude, and accepting the airspeed that is achieved, which should be close to the figure published in your Pilot’s Operating Handbook. On occasions, however, there is a need to fly at other than normal cruise airspeed. Today, we’ll discuss the basics of changing speeds in straight-and-level flight with an excerpt from The Pilot’s Manual: Instrument Flying (PM-3D).

This requires a different pitch attitude and a different power setting. To slow the airplane, the pilot reduces power and gradually raises the pitch attitude to maintain altitude; to increase airspeed, the pilot increases power, and gradually lowers the pitch attitude to maintain altitude.

Once the desired airspeed is achieved, the pilot adjusts the power to maintain it. The precise power required for steady flight will depend upon the amount of total drag, which, in level flight, varies with angle of attack and airspeed. Higher power will be required for:

  • high speed cruise (when total drag is high mainly due to parasite drag); and
  • low speed cruise (when total drag is high mainly due to induced drag).

pm-3d_4-25
Medium power is required for normal cruise. The ASI confirms whether or not correct power is set. The ASI is the primary performance guide to power requirements during level flight if you fly a particular airspeed.

Practicing airspeed changes in cruise is excellent instrument flying practice since pitch, bank (and balance) and power changes must all be coordinated to maintain constant altitude and heading. When the pilot changes power, a single-engined propeller- driven airplane will tend to move around all three axes of movement. If the propeller rotates clockwise as seen from the cockpit (the usual case), adding power will cause the nose to pitch up and yaw left, with a tendency for the airplane to roll left.

The pilot can counteract this by applying forward elevator pressure to prevent the nose pitching up, with right rudder and right aileron pressure to overcome the tendency to yaw and roll left. The converse applies when reducing power, hold the nose up and apply left rudder pressure. Refer to the AI to keep the wings level and hold the pitch attitude, and keep the ball centered.

Some hints on changing cruising speed follow:

  • The attitude indicator gives a direct picture of pitch and bank attitudes.
  • The ball gives a direct indication of coordination.
  • Useful performance instruments are the altimeter and VSI—they ensure altitude is being maintained, and the heading indicator to ensure heading is being maintained.
  • The airspeed indicator indicates the power requirements. If too slow, add more power; if too fast, reduce power.

The pilot’s scan rate of the flight instruments during any power change needs to be reasonably fast to counteract the pitch/yaw effects smoothly and accurately. For this reason, it is good to develop the skill of judging power changes by throttle movement and engine sound, rather than only by observation of the power indicator. This allows the pilot to concentrate on the flight instruments until after the power change has been made, at which time a quick glance at the power indicator for fine adjustment suffices.

When you memorize the approximate power settings necessary to maintain the various cruise speeds, then power handling and airspeed changes become simpler to manage.

Small airspeed changes (say five knots either way) can generally be handled by a single small power change, then allowing the airplane to gradually slow down or accelerate to the desired speed. Large airspeed changes, however, are most efficiently achieved within a few seconds by underpowering on the initial power change for a speed decrease, or overpowering on the initial power change for a speed increase. This allows more rapid deceleration or acceleration to the desired speed, at which time the necessary power to maintain that airspeed is set.

Once the desired airspeed is achieved and suitable power is set, the ASI will indicate if further fine adjustment of power to maintain airspeed is required. In level flight, the ASI is the primary guide to power requirements.

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CFI Brief: Caution for the wake turbulence from the departing 757

Today we are going to take a look at wake turbulence, which is the disturbed air left behind an airplane. Why you may ask is this important to us? This disturbed air left behind an aircraft can form tornado like vortices that are dangerous to all aircraft, particularly smaller general aviation aircraft operating behind a larger and heavier aircraft.

I’m sure you have heard of the term wake before, especially if you are a boater. A boats wake is very similar in nature to that of an aircraft. You can see from the image below as the boat motors along it displaces the water leaving behind a wake in the form of waves which spread in an outward direction.

boat wake

An aircraft’s wake is similar but differs in some characteristics and in the fact that typically wake turbulence created by an aircraft is not visible.

All aircraft leave two types of wake turbulence: Prop or jet blast, and wing-tip vortices.

Prop or jet blast is the thrust stream created by the engine. You will encounter this type of wake on the ground and is hazardous to light aircraft behind large aircraft which are either taxiing or running-up their engines. In the air, jet or prop blast dissipates rapidly.

Wing-tip vortices are a by-product of lift. As a wing produces lift, the higher static pressure area beneath the wing causes airflow around the wingtip to the lower pressure area above. To simplify the high pressure below the wing which creates lift wants to equalize with the lower pressure above the wing. The shortest point for the high pressure to move to the lower pressure area above the wing is at the wing tip. This high pressure moves outward, upward and around each wing-tip. However, because the wing and aircraft itself are moving, by the time the high pressure circulates around the tip to the top, the wing is now gone. This in turn creates vortices that trail behind each wing tip as seen in this image.

TP-P-01-27

The strength of a vortex is governed by the weight, speed, and the shape of the wing of the generating aircraft. Maximum vortex strength occurs when the generating aircraft is heavy, clean, and slow.  A heavy, clean, and slow aircraft will require a greater angle of attack (AoA) to great sufficient lift, as the AoA increases so does the pressure differential. The greater the pressure differential the stronger the vortice.

Vortices generated by large aircraft in flight tend to sink below the flight path of the generating aircraft at a rate of about 500 feet per minute. A pilot should fly at or above the larger aircraft’s flight path in order to avoid the wake turbulence created by the wing-tip vortices. Over time the vortices also tend to move apart and will drift downwind of the aircraft flight path. A common rule of thumb is to fly above and upwind of the path of other aircraft.

Close to the ground, vortices tend to move laterally. A crosswind will tend to hold the upwind vortex over the landing runway, while a tailwind may move the vortices of a preceding aircraft forward into the touchdown zone. Research has also shown that as vorticies come in contact striking the gorund that have a tendency to “bounce” back up as much as 250 feet.

To avoid wake turbulence when landing, a pilot should note the point where a preceding large aircraft touched down and then land past that point.

Wake Landing

 

On takeoff, lift off should be accomplished prior to reaching the rotation point of a preceding departing large aircraft; the flight path should then remain upwind and above the preceding aircraft’s flight path. If departing behind a landing large aircraft delay your takeoff point to a spot past where the landing aircraft touched down.

Wake TO

 

1. When landing behind a large aircraft, the pilot should avoid wake turbulence by staying
A—above the large aircraft’s final approach path and landing beyond the large aircraft’s touchdown point.
B—below the large aircraft’s final approach path and landing before the large aircraft’s touchdown point.
C—above the large aircraft’s final approach path and landing before the large aircraft’s touchdown point.

2. When departing behind a heavy aircraft, the pilot should avoid wake turbulence by maneuvering the aircraft
A—below and downwind from the heavy aircraft.
B—above and upwind from the heavy aircraft.
C—below and upwind from the heavy aircraft.

.

.

.

.
1. When landing behind a large aircraft stay at or above the large aircraft’s final approach path. Note its touchdown point and land beyond it.
Answer (B) is incorrect because below the flight path, you will fly into the sinking vortices generated by the large aircraft. Answer (C) is incorrect because by landing before the large aircraft’s touchdown point, you will have to fly below the preceding aircraft’s flight path, and into the vortices.

2. When departing behind a large aircraft, note the large aircraft’s rotation point, rotate prior to it, continue to climb above it, and request permission to deviate upwind of the large aircraft’s climb path until turning clear of the aircraft’s wake.

 

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CFI Brief: Deciphering the METAR

Today we are going to take a look at your most common type of weather report, the Aviation Routine Weather Report, abbreviated as METAR. A METAR is an observation of current surface weather reported in a standard international format. The purpose is to provide pilots with an accurate depiction of current weather conditions at an airport. METARs are issued on a regularly scheduled basis, usually somewhere close to the top of the hour, unless significant weather changes have occurred. If this is the case then a special METAR or ‘SPECI’ will be issued at any time between routine reports.

Here is an example of a routine METAR report for a station location.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

This METAR reports contains the following typical information in sequential order which is the standard formatted coding for all METAR reports.

1. Type of report. There are two types of METAR reports. The first is the routine METAR report that is transmitted on a regular time interval. The second is the aviation selected SPECI. This is a special report that can be given at any time to update the METAR for rapidly changing weather conditions, aircraft mishaps, or other critical information.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR]

2. Station identifier. A four-letter code as established by the International Civil Aviation Organization (ICAO). In the 48 contiguous states, a unique three-letter identifier is preceded by the letter “K.” For example, Gregg County Airport in Longview, Texas, is identified by the letters “KGGG,” K being the country designation and GGG being the airport identifier. In other regions of the world, including Alaska and Hawaii, the first two letters of the four-letter ICAO identifier indicate the region, country, or state. Alaska identifiers always begin with the letters “PA” and Hawaii identifiers always begin with the letters “PH.” Station identifiers can be found by searching various websites such as DUATS and NOAA’s Aviation Weather Aviation Digital Data Services (ADDS).

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

3. Date and time of report. Depicted in a six-digit group (161753Z). The first two digits are the date. The last four digits are the time of the METAR/SPECI, which is always given in coordinated universal time (UTC). A “Z” is appended to the end of the time to denote the time is given in Zulu time (UTC) as opposed to local time. This METAR was issued on the 16th at 1753 Zulu.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

4. Modifier. Denotes that the METAR/SPECI came from an automated source or that the report was corrected. If the notation “AUTO” is listed in the METAR/SPECI, the report came from an automated source. It also lists “AO1” (for no precipitation discriminator) or “AO2” (with precipitation discriminator) in the “Remarks” section to indicate the type of precipitation sensors employed at the automated station. When the modifier “COR” is used, it identifies a corrected report sent out to replace an earlier report that contained an error. If this was the case for this example the word AUTO would be replaced with COR.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

5. Wind. Reported with five digits (14021KT) unless the speed is greater than 99 knots, in which case the wind is reported with six digits. The first three digits indicate the direction the true wind is blowing from in tens of degrees. If the wind is variable, it is reported as “VRB.” The last two digits indicate the speed of the wind in knots unless the wind is greater than 99 knots, in which case it is indicated by three digits. If the winds are gusting, the letter “G” follows the wind speed (G26KT). After the letter “G,” the peak gust recorded is provided. If the wind direction varies more than 60° and the wind speed is greater than six knots, a separate group of numbers, separated by a “V,” will indicate the extremes of the wind directions.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

6. Visibility. The prevailing visibility (¾ SM) is reported in statute miles as denoted by the letters “SM.” It is reported in both miles and fractions of miles. At times, runway visual range (RVR) is reported following the prevailing visibility. RVR is the distance a pilot can see down the runway in a moving aircraft. When RVR is reported, it is shown with an R, then the runway number followed by a slant, then the visual range in feet. For example, when the RVR is reported as R17L/1400FT, it translates to a visual range of 1,400 feet on runway 17 left.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

7. Weather. Can be broken down into two different categories: qualifiers and weather phenomenon (+TSRA BR). First, the qualifiers of intensity, proximity, and the descriptor of the weather are given. The intensity may be light (–), moderate ( ), or heavy (+). Proximity only depicts weather phenomena that are in the airport vicinity. The notation “VC” indicates a specific weather phenomenon is in the vicinity of five to ten miles from the airport. Descriptors are used to describe certain types of precipitation and obscurations. Weather phenomena may be reported as being precipitation, obscurations, and other phenomena, such as squalls or funnel clouds. Descriptions of weather phenomena as they begin or end and hailstone size are also listed in the “Remarks” sections of the report. The coding for qualifier and weather phenomena are shown here in this chart. The weather groups are constructed by considering columns 1–5 in this table sequence: intensity, followed by descriptor, followed by weather phenomena. As an example “heavy rain showers” is coded as +SHRA.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

TP-UAS_3-5

8. Sky condition. Always reported in the sequence of amount, height, and type or indefinite ceiling/height (vertical visibility) (BKN008 OVC012CB, VV003). The heights of the cloud bases are reported with a three-digit number in hundreds of feet AGL. Clouds above 12,000 feet are not detected or reported by an automated station. The types of clouds, specifically towering cumulus (TCU) or cumulonimbus (CB) clouds, are reported with their height. Contractions are used to describe the amount of cloud coverage and obscuring phenomena. The amount of sky coverage is reported in eighths of the sky from horizon to horizon as shown in this table. Less than 1/8 is abbreviated as Sky Clear, Clear, or Few. 1/8 – 2/8 Few. 3/8 – 4/8 Scattered. 5/8 – 7/8 Broken. 8/8 Overcast. For aviation purposes, the ceiling is the lowest broken or overcast layer, or vertical visibility into an obscuration.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

TP-UAS_3-6

9. Temperature and dew point. The air temperature and dew point are always given in degrees Celsius (C) or (18/17). Temperatures below 0 °C are preceded by the letter “M” to indicate minus. 10.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

10. Altimeter setting. Reported as inches of mercury (“Hg) in a four-digit number group (A2970). It is always preceded by the letter “A.” Rising or falling pressure may also be denoted in the “Remarks” sections as “PRESRR” or “PRESFR,” respectively.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

11. Remarks—the remarks section always begins with the letters “RMK.” Comments may or may not appear in this section of the METAR. The information contained in this section may include wind data, variable visibility, beginning and ending times of particular phenomenon, pressure information, and various other information deemed necessary. An example of a remark regarding weather phenomenon that does not fit in any other category would be: OCNL LTGICCG. This translates as occasional lightning in the clouds and from cloud to ground. Automated stations also use the remarks section to indicate the equipment needs maintenance.

METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

Putting it all together you would read this sample METAR as follows:

Routine METAR for Gregg County Airport for the 16th day of the month at 1753 zulu automated source. Winds are 140 at 21 knots gusting to 26 knots. Visibility is ¾ statute mile. Thunderstorms with heavy rain and mist. Ceiling is broken at 800 feet, overcast at 1,200 feet with cumulonimbus clouds. Temperature 18 °C and dew point 17 °C. Barometric pressure is 29.70″Hg and falling rapidly.

TAF-METAR

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