Warm-Up – 9/21 – 10 minutes Utilizing your notes and past knowledge answer the following questions: CL increases with an increase in AOA, at some point the CL peaks and then begins to drop off. This peak is called ____________. The wing root reaches its critical AOA _____ making the stall progress _________ toward the wingtip. By having the wing root stall first, _________ effectiveness is maintained at the wingtips, maintaining __________ of the aircraft. Describe two methods used to achieve the stalling of the wing root first. Critical AOA varies from _________depending on the aircraft’s design.

Questions / Comments

Warm-Up – 9/21 – 10 minutes Utilizing your notes and past knowledge answer the following questions: CL increases with an increase in AOA, at some point the CL peaks and then begins to drop off. This peak is called ____________. The wing root reaches its critical AOA _____ making the stall progress _________ toward the wingtip. By having the wing root stall first, _________ effectiveness is maintained at the wingtips, maintaining __________ of the aircraft. Describe two methods used to achieve the stalling of the wing root first. Critical AOA varies from _________depending on the aircraft’s design.

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.

Warm-Up – 9/21 – 10 minutes Utilizing your notes and past knowledge answer the following questions: CL increases with an increase in AOA, at some point the CL peaks and then begins to drop off. This peak is called ____________. The wing root reaches its critical AOA _____ making the stall progress _________ toward the wingtip. By having the wing root stall first, _________ effectiveness is maintained at the wingtips, maintaining __________ of the aircraft. Describe two methods used to achieve the stalling of the wing root first. Critical AOA varies from _________depending on the aircraft’s design.

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.

Warm-Up – 9/21 – 10 minutes Utilizing your notes and past knowledge answer the following questions: CL increases with an increase in AOA, at some point the CL peaks and then begins to drop off. This peak is called ____________. The wing root reaches its critical AOA _____ making the stall progress _________ toward the wingtip. By having the wing root stall first, _________ effectiveness is maintained at the wingtips, maintaining __________ of the aircraft. Describe two methods used to achieve the stalling of the wing root first. Critical AOA varies from _________depending on the aircraft’s design.

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.

Warm-Up – 9/21 – 10 minutes Utilizing your notes and past knowledge answer the following questions: CL increases with an increase in AOA, at some point the CL peaks and then begins to drop off. This peak is called ____________. The wing root reaches its critical AOA _____ making the stall progress _________ toward the wingtip. By having the wing root stall first, _________ effectiveness is maintained at the wingtips, maintaining __________ of the aircraft. Describe two methods used to achieve the stalling of the wing root first. Critical AOA varies from _________depending on the aircraft’s design.

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.

Warm-Up – 9/21 – 10 minutes Utilizing your notes and past knowledge answer the following questions: CL increases with an increase in AOA, at some point the CL peaks and then begins to drop off. This peak is called ____________. The wing root reaches its critical AOA _____ making the stall progress _________ toward the wingtip. By having the wing root stall first, _________ effectiveness is maintained at the wingtips, maintaining __________ of the aircraft. Describe two methods used to achieve the stalling of the wing root first. Critical AOA varies from _________depending on the aircraft’s design.

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

THIS DAY IN AVIATION September 21 1802 — Frenchman Andre-Jacques Garnerin makes the first parachute descent in England, jumping from a balloon over London.

THIS DAY IN AVIATION September 21 1964 — The North American XB-70A “Valkyrie” makes his first flight.

Questions / Comments

September 2015 Chapter 4 Principles of Flight QUIZ Flightline Friday Sunday Monday Tuesday Wednesday Thursday Friday Saturday   6 7 HOLIDAY 8 Chapter 4 Principles of Flight 9 10 11 QUIZ Flightline Friday 12 13 14 Principles of Flight 15 16 17 18 Flightline 19 20 21 22 23 Progress Reports Due 24 25 Quiz Progress Reports Sent Home 26

1st Quarter Requirements (18 Class Meetings – Oct 14) All students will complete the following: Take notes - All in class quizzes and tests Each day is worth 20pts - (4 day week 25pts) Complete Flight Sim. Tutorials (1 – 5 x3 + 1) Aircraft Fam. and Student Pilot Syllabus Lessons 1 – 7 (Straight & Level Flight through First Solo) Must pass written with 80% Successfully complete 3 times on small sim Successfully complete 1 time on Main sim Complete ERAU Aviation 101 6 quizzes and 2 tests Student will receive zero points for all incomplete work – NO make-up / extra credit

November 2014 2 3 Chapter 4 Forces of Flight Stalls 4 No School 5 6 7 Sunday Monday Tuesday Wednesday Thursday Friday Saturday   2 3 Chapter 4 Forces of Flight Stalls 4 No School 5 6 7 8 9 10 Basic Propeller Principles Torque 11 12 13 Stall Load Factors Chapter 4 Quiz 14 15 16 17 Weight & Balance 18 19 20 21 Chapter 4 Test FltLine Friday Progress Reports 22 23 24 25 26 27 28 29

Questions / Comments

AVIATION ACES High Shooter (93) 4A 4A Pilots (A – 93 & above) Co-Pilots (B – 85 – 92) A to Z Not so Lonely Knight Rider Dragon Knight Hawk Reaper Kut Falcon High Shooter (93)

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.

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 during a turn the AOA becomes excessive, the aircraft stalls.

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. Caution - 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 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.

Questions / Comments

1st Quarter Requirements (18 Class Meetings – Oct 14) All students will complete the following: Take notes - All in class quizzes and tests Each day is worth 20pts - (4 day week 25pts) Complete Flight Sim. Tutorials (1 – 5 x3 + 1) Aircraft Fam. and Student Pilot Syllabus Lessons 1 – 7 (Straight & Level Flight through First Solo) Must pass written with 80% Successfully complete 3 times on small sim Successfully complete 1 time on Main sim Complete ERAU Aviation 101 6 quizzes and 2 tests Student will receive zero points for all incomplete work – NO make-up / extra credit

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