Warm-Up – 11/12 – 10 minutes Utilizing your notes and past knowledge answer the following questions: If an aircraft climbs with no change in the power setting – what happens to airspeed? Additional _____ is required to maintain the same airspeed as in level flight, when an aircraft climbs. When the excess thrust is gone, the aircraft is no longer able to climb. It is said that an aircraft has reached its_________ __________. What type of input is required of a pilot in order to initiate descent? To descend at the same airspeed as used in straight- and-level flight, what must be reduced as the descent is entered?

Questions / Comments

Warm-Up – 11/12 – 10 minutes Utilizing your notes and past knowledge answer the following questions: If an aircraft climbs with no change in the power setting – what happens to airspeed? Additional _____ is required to maintain the same airspeed as in level flight, when an aircraft climbs. When the excess thrust is gone, the aircraft is no longer able to climb. It is said that an aircraft has reached its_________ __________. What type of input is required of a pilot in order to initiate descent? To descend at the same airspeed as used in straight- and-level flight, what must be reduced as the descent is entered?

Aerodynamic Forces in Flight Maneuvers Forces in Climbs If the climb is entered with no change in power setting, the airspeed gradually diminishes because the thrust required to maintain a given airspeed in level flight is insufficient to maintain the same airspeed in a climb.

Warm-Up – 11/12 – 10 minutes Utilizing your notes and past knowledge answer the following questions: If an aircraft climbs with no change in the power setting – what happens to airspeed? Additional _____ is required to maintain the same airspeed as in level flight, when an aircraft climbs. When the excess thrust is gone, the aircraft is no longer able to climb. It is said that an aircraft has reached its_________ __________. What type of input is required of a pilot in order to initiate descent? To descend at the same airspeed as used in straight- and-level flight, what must be reduced as the descent is entered?

Aerodynamic Forces in Flight Maneuvers Forces in Climbs Additional power is required to maintain the same airspeed as in level flight.

Warm-Up – 11/12 – 10 minutes Utilizing your notes and past knowledge answer the following questions: If an aircraft climbs with no change in the power setting – what happens to airspeed? Additional _____ is required to maintain the same airspeed as in level flight, when an aircraft climbs. When the excess thrust is gone, the aircraft is no longer able to climb. It is said that an aircraft has reached its_________ __________. What type of input is required of a pilot in order to initiate descent? To descend at the same airspeed as used in straight- and-level flight, what must be reduced as the descent is entered?

Aerodynamic Forces in Flight Maneuvers Forces in Climbs When the excess thrust is gone, the aircraft is no longer able to climb. At this point, the aircraft has reached its “absolute ceiling.”

Warm-Up – 11/12 – 10 minutes Utilizing your notes and past knowledge answer the following questions: If an aircraft climbs with no change in the power setting – what happens to airspeed? Additional _____ is required to maintain the same airspeed as in level flight, when an aircraft climbs. When the excess thrust is gone, the aircraft is no longer able to climb. It is said that an aircraft has reached its_________ __________. What type of input is required of a pilot in order to initiate descent? To descend at the same airspeed as used in straight- and-level flight, what must be reduced as the descent is entered?

Aerodynamic Forces in Flight Maneuvers Forces in Decents Forward pressure is applied to the control yoke to initiate the descent, the AOA is decreased momentarily.

Warm-Up – 11/12 – 10 minutes Utilizing your notes and past knowledge answer the following questions: If an aircraft climbs with no change in the power setting – what happens to airspeed? Additional _____ is required to maintain the same airspeed as in level flight, when an aircraft climbs. When the excess thrust is gone, the aircraft is no longer able to climb. It is said that an aircraft has reached its_________ __________. What type of input is required of a pilot in order to initiate descent? To descend at the same airspeed as used in straight- and-level flight, what must be reduced as the descent is entered?

Aerodynamic Forces in Flight Maneuvers Forces in Decents To descend at the same airspeed as used in straight-and-level flight, the power must be reduced as the descent is entered.

Questions / Comments

THIS DAY IN AVIATION November 12 1903 — The first fully practical airship, the Lebaudy, makes a successful flight in Paris, France. The 190-foot-long airship flies 38½ miles and achieves a speed of 25- mph.

THIS DAY IN AVIATION November 12 1912 — The first successful catapult launch of a seaplane is made at the Washington, D.C. Navy Yard. Catapulted by a compressed air system from an anchored barge, the floatplane is a Curtiss A-1.

THIS DAY IN AVIATION November 12 1921 — The first air-to- air refueling is made when American Wesley May steps from the wing of one aircraft to that of another carrying a five-gallon can of gasoline strapped to his back.

THIS DAY IN AVIATION November 12 1957 — Defense Secretary Neil H. McElroy orders the United States Army to prepare to launch an Earth satellite. A modified ”Jupiter-C” test vehicle will be used.

Questions / Comments

November 2013 3 4 5 Chapter 4 Forces of Flight - Turns 6 7 Sunday Monday Tuesday Wednesday Thursday Friday Saturday   3 4 5 Chapter 4 Forces of Flight - Turns 6 7 Forces of Flight – Climbs Decents 8 9 10 11 No School 12 Forces of Flight Stalls 13 14 15 16 17 18 Basic Propeller Principles 19 20 21 22 Chapter 4 Quiz FltLine Friday Flight Simulator Progress Reports 23 24 25 26 27 28 29 30

Questions / Comments

Chapter 4 – Aerodynamics of Flight FAA – Pilot’s Handbook of Aeronautical Knowledge

Today’s Mission Requirements Identify in writing the forces acting on an aircraft in flight. Describe how the forces of flight work and how to control them with the use of power and flight controls essential to flight. Describe the aerodynamics of flight. Describe in writing how design, weight, load factors, and gravity affect an aircraft during flight maneuvers. EQ: Describe the importance of Aeronautical Knowledge for the student pilot learning to fly.

Airfoil Stall

Aerodynamic Forces in Flight Maneuvers Stalls An aircraft stall results from a rapid decrease in lift caused by the separation of airflow from the wing’s surface brought on by exceeding the critical AOA. A stall can occur at any pitch attitude or airspeed.

Aerodynamic Forces in Flight Maneuvers Stall In a stall, the wing does not totally stop producing lift. Rather, it can not generate adequate lift to sustain level flight.

Aerodynamic Forces in Flight Maneuvers Stalls CL increases with an increase in AOA, at some point the CL peaks and then begins to drop off. This peak is called the CL-MAX.

Aerodynamic Forces in Flight Maneuvers Stalls The amount of lift the wing produces drops dramatically after exceeding the CL-MAX or critical AOA, but as stated above, it does not completely stop producing lift.

Aerodynamic Forces in Flight Maneuvers Stalls In most straight-wing aircraft, the wing is designed to stall the wing root first. The wing root reaches its critical AOA first making the stall progress outward toward the wingtip.

Aerodynamic Forces in Flight Maneuvers Stalls By having the wing root stall first, aileron effectiveness is maintained at the wingtips, maintaining controllability of the aircraft. Various design methods are used to achieve the stalling of the wing root first.

Aerodynamic Forces in Flight Maneuvers Stalls In one design, the wing is “twisted” to a higher AOA at the wing root. Installing stall strips on the first 20–25 percent of the wing’s leading edge is another method to introduce a stall prematurely.

Aerodynamic Forces in Flight Maneuvers Stalls Most training aircraft are designed for the nose of the aircraft to drop during a stall, reducing the AOA and “unstalling” the wing.

Aerodynamic Forces in Flight Maneuvers Stalls The stalling speed of a particular aircraft is not a fixed value for all flight situations, but a given aircraft always stalls at the same AOA regardless of airspeed, weight, load factor, or density altitude.

Aerodynamic Forces in Flight Maneuvers Stalls This critical AOA varies from 16° to 20° depending on the aircraft’s design. But each aircraft has only one specific AOA where the stall occurs.

Questions / Comments

Lesson Closure - 3 – 2 - 1 2. List 2 things you have questions about today’s lesson. 3. List 3 things you learned today. 1. Create (1) quiz question with answer about today’s lesson.

Aerodynamic Forces in Flight Maneuvers Stalls There are three flight situations in which the critical AOA can be exceeded: low speed, high speed, and turning.

Aerodynamic Forces in Flight Maneuvers Stalls The aircraft can be stalled in straight-and-level flight by flying too slowly.

Aerodynamic Forces in Flight Maneuvers Stalls As the airspeed decreases, the AOA must be increased to retain the lift required for maintaining altitude. The lower the airspeed becomes, the more the AOA must be increased.

Aerodynamic Forces in Flight Maneuvers Stalls Low speed is not necessary to produce a stall. The wing can be brought into an excessive AOA at any speed. In a dive, the aircraft’s AOA changes abruptly from quite low to very high.

Aerodynamic Forces in Flight Maneuvers Stalls Since the flightpath of the aircraft in relation to the oncoming air determines the direction of the relative wind, the AOA is suddenly increased, and the aircraft would reach the stalling angle at a speed much greater than the normal stall speed.

Aerodynamic Forces in Flight Maneuvers Stalls The stalling speed of an aircraft is also higher in a level turn than in straight-and-level flight.

Aerodynamic Forces in Flight Maneuvers Stalls In a turn, additional lift is acquired by applying back pressure to the elevator control. This increases the wing’s AOA, and results in increased lift.

Aerodynamic Forces in Flight Maneuvers Stalls If at any time during a turn the AOA becomes excessive, the aircraft stalls.

Aerodynamic Forces in Flight Maneuvers Stalls To balance the aircraft aerodynamically, the CL is normally located aft of the CG. This makes the aircraft inherently nose-heavy, downwash on the horizontal stabilizer counteracts this condition.

Aerodynamic Forces in Flight Maneuvers Stalls At the point of stall, this allows the aircraft to pitch down abruptly, rotating about its CG. During this nose-down attitude, the AOA decreases and the airspeed again increases.

Aerodynamic Forces in Flight Maneuvers Stalls The smooth flow of air over the wing begins again, lift returns, and the aircraft is again flying. Considerable altitude may be lost before this cycle is complete.

Aerodynamic Forces in Flight Maneuvers Stalls Airfoil shape and degradation of that shape must also be considered in a discussion of stalls. If ice, snow, and frost are allowed to accumulate on the surface of an aircraft, the smooth airflow over the wing is disrupted.

Aerodynamic Forces in Flight Maneuvers Stalls This causes the boundary layer to separate at an AOA lower than that of the critical angle. Lift is greatly reduced, altering expected aircraft performance.

Aerodynamic Forces in Flight Maneuvers Stalls If ice is allowed to accumulate on the aircraft during flight the weight of the aircraft is increased while the ability to generate lift is decreased.

Aerodynamic Forces in Flight Maneuvers Stalls Icing can occur in clouds any time the temperature drops below freezing and super-cooled droplets build up on an aircraft and freeze.