RA

Chapter 1-7 Aviation Fundamentals - Vocabulary Flashcards

PIC and Flight Command

  • PIC stands for Pilot In Command. If you're flying with a crew, the captain is usually the PIC.
  • If you're flying by yourself, you are the PIC.
  • During your initial flight training, your flight instructor is the PIC because they are the experienced, certified pilot. They are teaching you how to become the PIC.
  • The PIC is directly responsible for everything that happens with the aircraft. All decisions about the flight are ultimately yours.
  • Here's a simple example: even if the coffee pot breaks, the PIC needs to know about it. This shows that the PIC is responsible for all operations on the aircraft, big or small.

Pilot Certification, Category, Class, and Type

  • When getting your pilot certification, these terms are important:
    • Category: This refers to the broad group of aircraft. For airplane training, your category is 'airplane'. If you wanted to fly helicopters, your category would be 'rotorcraft', and for gliders, it would be 'glider'.
    • Class: This further defines the aircraft within a category. In this program, for a single-engine airplane flying from land, your class is 'single engine land'. If you flew a two-engine airplane, it would be 'multi-engine land'. If that two-engine plane had floats for water landings, it would be 'multi-engine seaplane'.
  • It's important to differentiate: the 'category' we just discussed (airplane, rotorcraft) refers to you as the pilot (your airman certificate). The aircraft itself also has its own certification categories, such as normal, utility, transport, aerobatic, restricted, and experimental.
  • Understanding Airman vs. Aircraft Certificates:
    • Your Airman Certificate is your pilot's license; it covers what you are allowed to fly.
    • Aircraft Certificates define how the aircraft is built and what it's allowed to do (e.g., normal, utility, transport, aerobatic, restricted, experimental categories).
  • The Cessna Skyhawk 172, the plane you'll likely use, is certified in the 'normal/utility' aircraft category.
  • Understanding G-loads (Maximum Load Factor) for the Skyhawk:
    • In the 'utility' category, this aircraft can safely withstand up to 4.4\,g (meaning 4.4 times the force of gravity).
    • In the 'normal' category, it can handle up to +3.8\,g.
    • There's also a limit for negative Gs, around -1.5\,g. Negative Gs are restricted because sustained downward forces can cause structural damage to the aircraft.
  • Not all airplanes can easily switch between these categories. Changing an aircraft's certification category usually requires significant design changes and approval from the FAA (Federal Aviation Administration).
  • Part 121 and Commercial Airlines:
    • For an aircraft to be used by a Part 121 air carrier (which refers to major airlines), it must typically be a multi-engine plane, have at least 19 passenger seats, and a maximum takeoff weight over 19,000 pounds. These requirements usually put the airplane into the 'transport' category.
    • Part 121 is a specific regulation that applies to large commercial airlines in the United States.
  • Experimental and Restricted Aircraft Categories:
    • An Experimental aircraft has a special airworthiness certificate. These are often custom-built planes (kit builds) or aircraft that have undergone significant modifications.
    • A Restricted aircraft is typically used for specific purposes like military operations or specialized jobs (e.g., crop dusting). They usually cannot carry passengers for hire and have other operational limitations.
  • Quick Reminders for Aviation Students:
    • Don't try to use a Skyhawk for operations it wasn't certified for. Always follow FAA rules and processes for any modifications.
    • If you dream of flying for airlines, remember that those large airplanes operate under Part 121 certifications.

Aircraft Description and Certification (Airman vs Aircraft)

  • Aircraft can be certified into different categories based on their design and intended use: normal, utility, transport, aerobatic, restricted, and experimental.
  • The Skyhawk aircraft you'll be flying is certified for 'normal/utility' operations. While it might theoretically be possible to modify it for aerobatics (stunt flying), this is not recommended or done during flight training.
  • When an aircraft model is chosen or certified for a category, it depends on its design, weight, and what it's meant to do (like aerobatics, basic training, or carrying many passengers).
  • Remember, 'Part 121' specifically refers to the regulations for major airline operations, which have strict requirements.
  • The main idea is that an aircraft's certification category determines its safe operating limits (flight envelope) and what kind of flying it's allowed to do. For example, you need an aerobatic-certified plane for aerobatics, and a plane doing agricultural work or banner towing might be in the restricted category.

The Aircraft and Its Components (Skyhawk)

  • Let's look at the basic layout of the Skyhawk. Its fuel tanks are located inside the wings, accessed through red fuel caps on the top surface of each wing.
  • Important Notes on the Fuel System:
    • The fuel caps are 'vented,' meaning they have small openings. This is important because the fuel system uses gravity to feed fuel to the engine. Venting prevents a vacuum from forming as fuel is used, ensuring a smooth flow.
  • Primary Flight Controls (which control movement around the three main axes of the aircraft):
    • Ailerons: These are on the outer part of the wings. They control the aircraft's roll (tilting motion, like banking) around the longitudinal axis (an imaginary line running from nose to tail).
    • Elevator: This is on the rear part of the horizontal stabilizer (the small wing at the back). It controls the aircraft's pitch (nose up or down) around the lateral axis (an imaginary line running wingtip to wingtip).
    • Rudder: This is on the vertical stabilizer (the tail fin). It controls the aircraft's yaw (nose left or right) around the vertical axis (an imaginary line running up through the center of the plane).
    • Elevator Trim Tab: This is a small, adjustable surface on the elevator. It helps 'trim' the aircraft, meaning it reduces the pilot's effort needed to maintain a specific pitch attitude. In the Skyhawk, it's typically controlled by a manual wheel, but it can be electronic in other aircraft.
    • Rudder Trim: The Skyhawk also has rudder trim, which helps counteract forces like engine torque that try to make the aircraft turn or slip to one side, reducing the need for constant rudder pedal input.
  • Stabilizer vs. Stabilator Explained:
    • The Skyhawk has a fixed horizontal stabilizer with a movable elevator attached to its trailing edge. A stabilator, on the other hand, is when the entire horizontal tail surface moves to control pitch.
  • Primary vs. Secondary Flight Controls:
    • Primary controls: Ailerons, elevator, and rudder are essential for basic flight maneuvers.
    • Secondary controls: Flaps and trim are used to help manage the aircraft's performance and reduce pilot workload.
  • Flaps:
    • Flaps are located on the inner portion of the wings, closer to the fuselage. In most training aircraft, they are moved by an electric motor.
    • They can be extended in specific increments, like 10^\circ, 20^\circ, or 30^\circ down.
    • When extended, flaps do three things: they increase lift (by increasing the effective surface area of the wing and its curvature or 'camber') and they increase drag.
  • How Trim Works:
    • Trim helps the pilot maintain a desired pitch attitude (nose up or down) and significantly reduces the physical effort needed to fly, especially when engine power changes.
    • For example, if you increase engine power to climb, the aircraft's nose will naturally want to pitch up. To keep a constant climb angle or angle of attack, you would use the trim wheel to apply a nose-down force, reducing the need to push forward on the yoke.
    • Conversely, if you reduce power (like to descend or slow down), the nose will want to drop. You would then trim nose-up to maintain your desired flight attitude.
    • Learning to use trim correctly with your instructor is crucial as it makes flying much easier.
  • Flight Control Cautions and Tips:
    • When checking the elevator trim tab during your pre-flight inspection or manual checks, don't move it roughly. These tabs are delicate, and excessive force can damage their cables.
    • The rudder trim on the Skyhawk is designed and set to help counter the aircraft's natural tendency to turn left, which is caused by the rotating propeller's airflow (slipstream) and other factors.
  • Understanding Left-Turning Tendencies (and other turning effects):
    • P-factor (Power Factor): This effect tends to push the aircraft's nose to the left, especially when flying at high power and low speeds (like during takeoff or climb). It's caused by the propeller blades having different angles of attack.
    • Torque Reaction: As the propeller spins in one direction (clockwise, looking from behind in most U.S. planes), it creates an opposite twisting force on the aircraft, making the aircraft want to roll and yaw to the left. You counteract this with right rudder.
    • Spiraling Slipstream: The air pushed backward by the propeller wraps around the fuselage in a spiral. This spiraling air often hits the left side of the vertical stabilizer (tail fin) and rudder, pushing the aircraft's nose to the left.
    • Gyroscopic Precession: The spinning propeller acts like a gyroscope. When a force is applied to a spinning gyroscope, the resulting force is felt 90 degrees ahead in the direction of rotation. So, pitching the nose up (or down) can create a yawing moment, often requiring right rudder to counteract this left-turning tendency.
    • During takeoff, especially when you apply full power at low speeds (from 0 to around 55 knots), the aircraft will strongly tend to yaw (turn) to the left. You must use significant right rudder to keep the plane straight on the runway. Your instructor will often help you manage this during early training.
  • Wake Turbulence (Induced Drag) and Considerations for Taking Off and Landing:
    • Induced drag, which is a byproduct of lift, is strongest when the aircraft is flying slowly and at a high angle of attack – conditions often found during takeoff and landing.
    • When you take off or land behind a large aircraft (especially jets), you can encounter dangerous wake turbulence. This consists of powerful swirling air vortices trailing from the wingtips. You should either wait for the wake to dissipate or adjust your takeoff/landing path to be ahead of or away from where the wake would be.
  • Ground Effect and Soft-Field Takeoff:
    • As an airplane flies very close to the ground, a 'cushion' of air forms between the wings and the surface. This ground effect reduces induced drag and makes the aircraft feel like it produces more lift, allowing it to lift off earlier than it would at higher altitudes. For many light trainers, the plane will tend to lift off when the nose is rotated up at around 55 knots of airspeed.
    • A soft-field takeoff technique utilizes ground effect to get the aircraft airborne quickly, sometimes at a lower airspeed, to avoid obstacles or soft ground. Once the aircraft is flying within the ground effect 'bubble' (usually about one wingspan above the ground), you then slowly accelerate to a safe climbing speed before leaving ground effect, ensuring enough speed to sustain flight away from the ground.
  • Practical Tips for Managing Wake Turbulence:
    • If a large jet has just used your runway, remember it will leave wake turbulence. To avoid it, you should either wait a few minutes for the wake to move away, or if you're taking off, lift off before the jet's rotation point and then climb above its flight path using your best angle of climb speed (V_X).

The Four Forces of Flight

  • All aircraft in flight are acted upon by four main forces:
    • Lift: The upward force that opposes gravity and keeps the aircraft in the air.
    • Weight (or Gravity): The downward force caused by the aircraft's mass being pulled towards the Earth.
    • Thrust: The forward force generated by the engine and propeller (or jet engines) that pushes the aircraft through the air.
    • Drag: The backward force that opposes thrust and is caused by air resistance.
  • How Lift and Weight Interact:
    • For an aircraft to fly level (not climbing or descending), the lift it generates must be equal to its weight (L = W). To climb, lift must be greater than weight.
  • Where Does Lift Come From? (Two main explanations taught for exams):
    • Newton's Third Law of Motion: This explains that for every action, there is an equal and opposite reaction. As the wing pushes air downwards, the air pushes the wing upwards, creating lift.
    • Bernoulli's Principle: This states that as the speed of a fluid (like air) increases, its pressure decreases. The curved shape of a wing (airfoil) causes air flowing over the top to move faster than the air flowing underneath, creating lower pressure on top. This pressure difference results in a net upward force, which is lift.
  • Important Notes on Understanding Lift:
    • Both Newton's and Bernoulli's principles contribute to explaining lift. Lift isn't just one simple effect; it's a combination of these aerodynamic forces working against gravity (weight).
    • For FAA exams and training, lift is usually explained using both Bernoulli's principle (faster air over the wing leading to lower pressure on top) and Newton's third law (the wing pushing air down, and the air pushing the wing up).
    • While lift is a complex physical theory, in aviation, these principles provide the practical model used for aircraft design and pilot training.
  • Key Terms for Airfoils (Wing Shapes):
    • Leading edge: The very front part of the wing, which first meets the air.
    • Camber: The curved shape of the wing, both on its upper surface (upper camber) and lower surface (lower camber).
    • Trailing edge: The rearmost part of the wing where the airflow separates.
    • Chord line: An imaginary straight line connecting the leading edge to the trailing edge of the wing.
    • Angle of Attack (AoA): This is the angle between the relative wind (the airflow coming towards the wing) and the chord line. It essentially describes how much the wing is tilted into the airflow.
  • Wing Shapes and Terms (Wing Geometry):
    • Wingspan: The total distance from the tip of one wing to the tip of the other.
    • Aspect Ratio: This is calculated as the ratio of the wingspan squared to the wing's total area, or more simply, \text{Aspect ratio} = \frac{\text{wingspan}}{\text{average chord}}. Wings with a high aspect ratio (long and slender, like glider wings) generally have less induced drag (a type of drag that comes from making lift) and are more efficient.
    • Planform Area: This is the total flat area of the wing when viewed from above. The shape and size of the wing's planform significantly affect how much lift and drag it produces.
    • Common Wing Shapes (Planforms):
    • Common shapes include rectangular, tapered, swept-back, delta, and elliptical wings.
    • The Skyhawk's wing shape is a mix, generally tapered towards the tips from a more rectangular root. Each planform shape has different characteristics regarding drag, lift, and how the plane handles, especially during a stall.
  • More on Wings and Lift:
    • Wings with a higher aspect ratio (long and slender) are more efficient, producing more lift for a given amount of drag, which is why gliders use them.
    • Elliptical wings are designed to minimize induced drag for a certain weight but are less common in small training aircraft due to manufacturing complexity.
    • The shape of the wing (planform) also significantly impacts how the aircraft stalls and its maneuverability.
  • Lift vs. Weight Relationship (and Mass vs. Weight):
    • Weight is the force of gravity acting on the aircraft's mass. In U.S. aviation, weight is measured in pounds (lb).
    • While mass is a measure of how much 'stuff' an object contains, in aviation, we focus on weight, which is specifically the force due to gravity, always measured in pounds.
    • For an aircraft to maintain steady, level flight, the amount of lift it generates must exactly balance its total weight. This balance between lift and weight is fundamental to how an aircraft climbs, cruises, and descends, especially in larger jets and turboprops.
  • A Note on Weight and Balance (Future Topic):
    • The aircraft's overall weight and its center of gravity (CG) — where the aircraft's weight is balanced — are critical. They significantly impact how the plane performs and its stability. We will study weight and balance in much more detail later.
  • How to Increase Lift (to balance weight or climb):
    • Increase engine thrust (power). This increases airspeed, which in turn generates more lift.
    • Increase airspeed. Faster airflow over the wings directly creates more lift for a given angle of attack.

Induced Drag, Parasitic Drag, and Stall Mechanics

  • Overview of Drag:
    • Parasitic Drag: This type of drag is caused by any part of the aircraft that is not designed to produce lift. It includes form drag (from the shape of objects like landing gear and antennas), skin-friction drag (from air rubbing against the aircraft's surface), and interference drag (where airflows combine, like at wing-fuselage junctions).
    • Induced Drag: This drag is an unavoidable consequence of producing lift. It's generated by the swirling air (wingtip vortices) that forms at the wingtips as the wing creates lift. Induced drag increases when the wing is producing more lift, especially at higher angles of attack and slower airspeeds.
  • Detailed Types of Drag:
    • Form Drag: Arises from the shape and size of non-aerodynamic parts exposed to the airflow, such as the fuselage, landing gear, or antennas.
    • Skin Friction Drag: Occurs when air directly rubs against the aircraft's surface. It increases with surface roughness (like frost, dents, or peeling paint) because of increased friction between the air and the aircraft.
    • Interference Drag: This happens when airflows from different parts of the aircraft meet and interact, creating turbulence (e.g., where the wing joins the fuselage). It is usually considered a type of parasitic drag.
    • Induced Drag: As mentioned, this is directly related to the production of lift. When a wing creates lift, it also creates swirling air behind it, called wingtip vortices (and other trailing eddies). The stronger the lift, the stronger these vortices, and the more induced drag they create.
  • Induced Drag and How It Relates to a Stall:
    • Induced drag is most significant when the aircraft is flying very slowly and at a high angle of attack, which often happens during takeoff and landing.
    • If the angle of attack (AoA) becomes too high, the smooth airflow over the top of the wing can separate and even reverse direction (called flow reversal). When this happens, the wing suddenly loses a significant amount of lift, and the aircraft experiences a stall.
    • Because of the Skyhawk's wing design (often slightly twisted or 'washout'), a stall typically begins at the wing root (the part closest to the fuselage) first, while the wingtips remain flying. To recover from a stall, you must immediately lower the nose of the aircraft to decrease the angle of attack. This allows the airflow to reattach smoothly over the wing and regain lift.
  • Basic Stall Recovery Steps:
    • To recover from a stall: 1) Immediately pitch the nose down to reduce the angle of attack and re-establish smooth airflow over the wings. 2) As flow reattaches, apply full engine power to regain airspeed and minimize altitude loss.
    • Once the airflow reattaches and airspeed increases, lift will return. After breaking the stall, gently adjust pitch and power to return to normal flight, ensuring you have enough altitude.
  • Wake Turbulence and Avoiding It When Departing:
    • The induced drag from a wing also creates wake turbulence (the swirling air from wingtips) that can be dangerous for other aircraft, especially smaller ones. You must avoid this turbulence or wait for it to dissipate.
    • If you're ever unsure about wake turbulence from a larger aircraft, it's always safest to wait a few minutes for it to move away or dissipate before taking off.
  • Ground Effect (Revisited for Drag):
    • Remember that ground effect helps reduce induced drag when you're flying very close to the runway, enabling the aircraft to become airborne sooner. However, once you climb out of this ground effect 'cushion,' the induced drag increases again, so you must have built up enough airspeed to maintain sustained flight.

Aerodynamics Terminology and Airfoil Fundamentals

  • Recap of Airfoil Terms:
    • Leading edge, trailing edge, camber (the curve on the upper and lower surfaces), and the chord line.
    • AoA (Angle of Attack): The angle between the airflow (relative wind) and the wing's chord line.
    • Wingspan, aspect ratio, and planform area are also key terms.
  • Wing Planform and Efficiency Notes:
    • Wings with a high aspect ratio (long and slender) are more efficient because they reduce induced drag. Elliptical wings also minimize induced drag. However, trainers often use simpler straight or slightly tapered wings for better stability and easier manufacturing.
  • Flaps: The Trade-off Between Lift and Drag:
    • Flaps increase the wing's surface area and its curvature (camber), which generates more lift. However, they also create more drag (specifically, parasitic drag increases due to the larger, less streamlined surface area).
  • Different Types of Flaps:
    • Plain flaps: These are simple hinged sections that just deflect downwards from the trailing edge of the wing.
    • Split flaps: Only the lower surface of the wing's trailing edge splits off and deflects downwards, while the upper surface stays fixed.
    • Slotted flaps: These create a gap or 'slot' between the wing and the flap when extended. This slot allows high-pressure air from beneath the wing to flow over the top of the flap, increasing lift and delaying airflow separation, though they also produce more drag.
    • Fowler flaps: These are more complex and slide backward and then deflect downward. This design significantly increases both the wing's surface area and its camber, providing a large increase in lift and drag.
  • Review of Weight and Lift Balance:
    • To stay in the air, the lift generated by the wings must always balance or exceed the aircraft's weight. If you add more load (weight) to the aircraft, you will need to generate more lift to maintain flight.
    • In the U.S. aviation context, both weight and lift are measured in pounds (lb), maintaining a balance according to physical laws.
    • Think of a boat floating: it displaces a weight of water equal to its own weight. Similarly, an airplane flies by displacing air, generating lift that is equal to or greater than its weight.
  • Thrust and Left-Turning Tendencies (Revisited):
    • Thrust is the forward force created by the engine rotating the propeller. The faster the propeller spins (higher RPMs), the more thrust and speed it generates.
    • In many U.S.-built airplanes, the propeller spins clockwise when viewed from the cockpit. This causes the aircraft to have a natural tendency to turn or 'yaw' to the left because of various effects like torque reaction. Pilots must apply right rudder pedal input to keep the aircraft flying straight.
    • Beyond torque, other factors contribute to this left-turning tendency: the spiraling slipstream, gyroscopic precession, and P-factor. All of these require the pilot to use appropriate right rudder input to maintain straight flight or runway alignment.
  • Takeoff Dynamics with Power:
    • During takeoff, as you apply more engine power, the left-turning tendency becomes stronger. You'll need to use more right rudder to keep the aircraft aligned with the runway.

Practical Flying Concepts and Tips (From Lecture)

  • Practical Tips for Ground Effect and Takeoff:
    • Ground effect provides an air cushion that helps the aircraft lift off sooner. Many small trainers will rotate their nose up at about 55 knots and use this ground effect to become airborne.
    • A soft-field takeoff technique uses ground effect to lift off at a lower speed. Once the aircraft is airborne and within the ground effect, you accelerate to a safe climbing speed before flying out of the ground cushion and climbing normally.
  • Being Aware of Wake Turbulence During Departure:
    • When you're taking off behind a large jet or airplane, be very mindful of its wake turbulence. You should either wait a few minutes for the wake to move away or dissipate, or if you must depart, aim to lift off before the large aircraft's rotation point and climb quickly above its projected flight path. Your actions will depend on the runway length, wind, and spacing.
  • Implications for Training in City/Airport Environments:
    • Your flight instructor will show you how to handle the aircraft's left-turning tendencies and other control inputs during your first flights. You'll then learn to anticipate these forces, especially during takeoff and the initial climb after leaving the runway.

Gleim Quizzes and Course Structure (PAR Exam Prep)

  • Using the Gleim Learning Platform:
    • Quizzes and assessments on the Gleim platform are a critical part of the course. You will have deadlines for completing each quiz, such as Quiz 1 needing to be done by September 14th.
    • You can access these quizzes through the Gleim app or online classroom. Each quiz allows you three attempts.
    • To successfully pass each homework assignment, you must achieve a score of at least 84% on its corresponding quiz.
  • Grading and Course Progression:
    • To earn an endorsement at the end of the semester (which is needed to take your practical flight test), you must score 84% or higher on all Gleim quizzes and pass the official FAA Private Pilot Written (PAR) exam with a score of 70% or higher.
    • Your final course grade will be determined by a combination of your quiz performance and your FAA PAR exam score. For example, consistently scoring 84% on quizzes combined with a 70% on the PAR exam would be a passing result. Higher scores on the quizzes can help improve your overall grade.
  • Syllabus Information:
    • Always refer to your course syllabus for precise details on how your final grade will be calculated and all the requirements needed to receive your endorsement.

Quick Reference Equations and Numerical Details

  • Quick Reference: Skyhawk G-Loads (Maximum Load Factors):
    • In the 'utility' category, the maximum G-load is 4.4\,g. This means the aircraft can withstand forces up to 4.4 times the force of gravity.
    • In the 'normal' category, the maximum positive G-load is +3.8\,g.
    • The limit for negative Gs is -1.5\,g.
  • Gravitational Constants and Units:
    • Gravitational acceleration (g) is approximately 9.8\,\text{m/s}^2 (meters per second squared).
    • Alternatively, it's about 32\,\text{ft/s}^2 (feet per second squared).
  • Lift vs. Weight Balance:
    • For steady, level flight, the lift force (L) must equal the weight (W) of the aircraft: L = W.
  • Aspect Ratio Definition:
    • Aspect ratio is defined as: \text{Aspect ratio} = \frac{\text{wingspan}}{\text{mean chord}} (the wingspan divided by the average chord length of the wing).
  • Brief Recap of Wing Terms: Leading edge, camber (upper/lower curve), chord line, Angle of Attack (AoA), and trailing edge.

Final Reminders and Course Focus

  • Always be ready to answer questions on exams about the PIC's responsibilities, the different aircraft categories, and fundamental aerodynamics concepts.
  • Practical aspects of flight, such as how to use flight controls, how an aircraft behaves during a stall, and the various turning tendencies, will be covered repeatedly in quizzes, assessments, and your actual flight training.
  • Remember this course utilizes Gleim quizzes and prepares you for the FAA Private Pilot Written (PAR) exam. Your goal should be to achieve 84% or higher on the quizzes and 70% or higher on the PAR exam to earn your endorsement.
  • Make sure to attend all class sessions and keep up with your studies, including reviewing preflight notes and the weight and balance concepts (which will be discussed in detail next week).
  • If you missed anything during the lecture, you can always refer to the PowerPoint slides available in Blackboard to review the terms, diagrams, and definitions mentioned here.

Attendance Note

  • Attendance will be taken at the end of each class. Please be ready to confirm your presence when your name is called.