warm-up – 11/12 – 10 minutes
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Utilizing your notes and past knowledge answer the following questions:
1) If an aircraft climbs with no change in the power setting – what happens to airspeed?
2) Additional _____ is required to maintain the same airspeed as in level flight, when an aircraft climbs.
3) When the excess thrust is gone, the aircraft is no longer able to climb. It is said that an aircraft has reached its_________ __________.
4) What type of input is required of a pilot in order to initiate descent?
5) To descend at the same airspeed as used in straight-and-level flight, what must be reduced as the descent is entered?
Warm-Up – 11/12 – 10 minutes
Questions / Comments
Utilizing your notes and past knowledge answer the following questions:
1) If an aircraft climbs with no change in the power setting – what happens to airspeed?
2) Additional _____ is required to maintain the same airspeed as in level flight, when an aircraft climbs.
3) When the excess thrust is gone, the aircraft is no longer able to climb. It is said that an aircraft has reached its_________ __________.
4) What type of input is required of a pilot in order to initiate descent?
5) To descend at the same airspeed as used in straight-and-level flight, what must be reduced as the descent is entered?
Warm-Up – 11/12 – 10 minutes
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.
Utilizing your notes and past knowledge answer the following questions:
1) If an aircraft climbs with no change in the power setting – what happens to airspeed?
2) Additional _____ is required to maintain the same airspeed as in level flight, when an aircraft climbs.
3) When the excess thrust is gone, the aircraft is no longer able to climb. It is said that an aircraft has reached its_________ __________.
4) What type of input is required of a pilot in order to initiate descent?
5) To descend at the same airspeed as used in straight-and-level flight, what must be reduced as the descent is entered?
Warm-Up – 11/12 – 10 minutes
Aerodynamic Forces in Flight Maneuvers
Forces in Climbs
• Additional power is required to maintain the same airspeed as in level flight.
Utilizing your notes and past knowledge answer the following questions:
1) If an aircraft climbs with no change in the power setting – what happens to airspeed?
2) Additional _____ is required to maintain the same airspeed as in level flight, when an aircraft climbs.
3) When the excess thrust is gone, the aircraft is no longer able to climb. It is said that an aircraft has reached its_________ __________.
4) What type of input is required of a pilot in order to initiate descent?
5) To descend at the same airspeed as used in straight-and-level flight, what must be reduced as the descent is entered?
Warm-Up – 11/12 – 10 minutes
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.”
Utilizing your notes and past knowledge answer the following questions:
1) If an aircraft climbs with no change in the power setting – what happens to airspeed?
2) Additional _____ is required to maintain the same airspeed as in level flight, when an aircraft climbs.
3) When the excess thrust is gone, the aircraft is no longer able to climb. It is said that an aircraft has reached its_________ __________.
4) What type of input is required of a pilot in order to initiate descent?
5) To descend at the same airspeed as used in straight-and-level flight, what must be reduced as the descent is entered?
Warm-Up – 11/12 – 10 minutes
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.
Utilizing your notes and past knowledge answer the following questions:
1) If an aircraft climbs with no change in the power setting – what happens to airspeed?
2) Additional _____ is required to maintain the same airspeed as in level flight, when an aircraft climbs.
3) When the excess thrust is gone, the aircraft is no longer able to climb. It is said that an aircraft has reached its_________ __________.
4) What type of input is required of a pilot in order to initiate descent?
5) To descend at the same airspeed as used in straight-and-level flight, what must be reduced as the descent is entered?
Warm-Up – 11/12 – 10 minutes
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
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.
THIS DAY IN AVIATION
Questions / Comments
SUNDAY MONDAY TUESDAY WEDNESDAY THURSDAY FRIDAY SATURDAY
3 4 5
Chapter 4
Forces of Flight - Turns
6 7
Chapter 4
Forces of Flight – Climbs
Decents
8 9
10 11
No School
12
Chapter 4
Forces of Flight
Stalls
13 14
Chapter 4
Forces of Flight
Stalls
15 16
17 18
Chapter 4
Forces of Flight
Basic Propeller Principles
19 20
Chapter 4
Forces of Flight
Basic Propeller Principles
21 22
Chapter 4 Quiz
FltLine Friday
Flight
Simulator
Progress Reports
23
24 25
No School
26
No School
27
No School
28
No School
29
No School
30
November 2013
Questions / Comments
Chapter 4 – Aerodynamics of FlightFAA – Pilot’s Handbook of Aeronautical Knowledge
Mission: 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.
Today’s Mission Requirements
AirfoilStall
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
3. List 3 things you learned today.
1. Create (1) quiz question with answer about today’s lesson.
2. List 2 things you have questions 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.
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