1. Warm-Up – 12/11 – 10 minutes
Utilizing your notes and past knowledge answer the following questions:
Define the effect of load factors and stalling speeds.
What is the maximum speed at which an aircraft may be stalled safely called?
What is the only way this type of stall can be induced at an airspeed above normal stalling with an added load factor?
What action should a pilot perform in extremely rough air to prevent possible stall?
Describe the two types of loads that can damage an aircraft.

2. Questions / Comments

3. Warm-Up – 12/11 – 10 minutes
Utilizing your notes and past knowledge answer the following questions:
Define the effect of load factors and stalling speeds.
What is the maximum speed at which an aircraft may be stalled safely called?
What is the only way this type of stall can be induced at an airspeed above normal stalling with an added load factor?
What action should a pilot perform in extremely rough air to prevent possible stall?
Describe the two types of loads that can damage an aircraft.

4. Load Factors and Stalling Speeds
A study of this effect has revealed that the aircraft’s stalling speed increases in proportion to the square root of the load factor.

5. Warm-Up – 12/11 – 10 minutes
Utilizing your notes and past knowledge answer the following questions:
Define the effect of load factors and stalling speeds.
What is the maximum speed at which an aircraft may be stalled safely called?
What is the only way this type of stall can be induced at an airspeed above normal stalling with an added load factor?
What action should a pilot perform in extremely rough air to prevent possible stall?
Describe the two types of loads that can damage an aircraft.

6. Load Factors and Stalling Speeds
The maximum speed at which an aircraft may be stalled safely is now determined for all new designs.
This speed is called the “design maneuvering speed” (VA).

7. Warm-Up – 12/11 – 10 minutes
Utilizing your notes and past knowledge answer the following questions:
Define the effect of load factors and stalling speeds.
What is the maximum speed at which an aircraft may be stalled safely called?
What is the only way this type of stall can be induced at an airspeed above normal stalling with an added load factor?
What action should a pilot perform in extremely rough air to prevent possible stall?
Describe the two types of loads that can damage an aircraft.

8. Load Factors and Flight Maneuvers
High Speed Stalls
The only way this stall can be induced at an airspeed above normal stalling with an added load factor, which may be accomplished by a severe pull on the elevator control.

9. Warm-Up – 12/11 – 10 minutes
Utilizing your notes and past knowledge answer the following questions:
Define the effect of load factors and stalling speeds.
What is the maximum speed at which an aircraft may be stalled safely called?
What is the only way this type of stall can be induced at an airspeed above normal stalling with an added load factor?
What action should a pilot perform in extremely rough air to prevent possible stall?
Describe the two types of loads that can damage an aircraft.

10. Load Factors and Flight Maneuvers
Rough Air
All standard certificated aircraft are designed to withstand loads imposed by gusts of considerable intensity.
In extremely rough air it is wise to reduce the speed to the design maneuvering speed.

11. Warm-Up – 12/11 – 10 minutes
Utilizing your notes and past knowledge answer the following questions:
Define the effect of load factors and stalling speeds.
What is the maximum speed at which an aircraft may be stalled safely called?
What is the only way this type of stall can be induced at an airspeed above normal stalling with an added load factor?
What action should a pilot perform in extremely rough air to prevent possible stall?
Describe the two types of loads that can damage an aircraft.

12. Load Factors and Flight Maneuvers
The limit load is a force applied to an aircraft that causes a bending of the aircraft structure that does not return to the original shape.

13. Load Factors and Flight Maneuvers
The ultimate load is the load factor applied to the aircraft beyond the limit load and at which point the aircraft material experiences structural failure (breakage).

14. Questions / Comments

15. THIS DAY IN AVIATION December 11
1917 — Katherine Stinson flies 606 miles from San Diego to San Francisco, setting a new American non-stop distance record.

16. THIS DAY IN AVIATION December 11
1928 — Privates Sidney R. Glover and Paul W. Lemons are awarded the Soldiers Medal for rescuing Major Junius W. Jones, United States Air Corps, and Maj. Samuel T. Stewart, C.A.C, from drowning after an airplane crash into the Mississippi River near Fort Leavenworth, Kansas.

17. Questions / Comments

18. December 2013 1 2 3 Chapter 4 Torque 4 5 Load Factors 6 7 8 9
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday 1 2 3
Chapter 4
Torque 4 5
Load Factors 6 7 8 9
Load Factors / Stalling Speeds 10 11
Load Factors Turns / Weight Balance 12 13
Chapter 4 Test
Flightline Friday 14 15 16 17 18 19 20 21 22 23
NO SCHOOL 24 25 26 27 28 29 30 31

19. Questions / Comments

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

22. 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 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.

23. Load Factors and Flight Maneuvers
Rate of Turn
The rate of turn (ROT) is the number of degrees (expressed in degrees per second) of heading change that an aircraft makes.

24. Load Factors and Flight Maneuvers
Radius of Turn
If the bank angle is held constant and the airspeed is increased, the radius of the turn changes (increases).
A higher airspeed causes the aircraft to travel through a longer arc due to a greater speed.

25. Two aircraft have flown into a canyon by error
Two aircraft have flown into a canyon by error. The canyon is 5,000 feet across and has sheer cliffs on both sides. The pilot in the top image is flying at 120 knots. After realizing the error, the pilot banks hard and uses a 30° bank angle to reverse course. This aircraft requires about 4,000 feet to turn 180°, and makes it out of the canyon safely.

26. The pilot is flying at 140 knots and also uses a 30° angle of bank in an attempt to reverse course. The aircraft, although flying just 20 knots faster than the aircraft in the top image, requires over 6,000 feet to reverse course to safety. Unfortunately, the canyon is only 5,000 feet across and the aircraft will hit the canyon wall. The point is that airspeed is the most influential factor in determining how much distance is required to turn. Many pilots have made the error of increasing the steepness of their bank angle when a simple reduction of speed would have been more appropriate.

27. Weight and Balance
Weight and balance computations should be part of every preflight briefing.
Never assume three passengers are always of equal weight.

28. Weight and Balance
Instead, do a full computation of all items to be loaded on the aircraft, including baggage, as well as the pilot and passenger.

29. Weight and Balance
It is recommended that all bags be weighed to make a precise computation of how the aircraft CG is positioned.

30. Weight and Balance
Aircraft are certificated for weight and balance for two principal reasons:
1. The effect of the weight on the aircraft’s primary structure and its performance characteristics.
2. The effect of the location of this weight on flight characteristics, particularly in stall and spin recovery and stability.

31. Weight and Balance Datum is at front face of firewall What now?
Presentation Name
Course Name
Unit # – Lesson #.# – Lesson Name
Weight and Balance
Datum is at front face of firewall
Force
Weight (lb)
Distance
Arm (in.)
Moment (in.-lb)
M = Fd = weight ● arm
Item
Empty weight
1,460
37.4
54,604 ?
160
37.0
5,920
Pilot
180
37.0
6,660
Co-pilot
Weight and balance calculations are the same as the torque concept learned in the POE curriculum. Moment is another term for torque. Torque is calculated by multiplying force applied at a right angle to distance from a pivot point. The force in this example is weight and arm is the distance between the pivot point and the force applied at a 90° angle. Note that in aviation operations the term weight is used in place of force as a specific force being considered for the weight and balance calculation. The term arm is used in place of distance as a specific distance being considered.
240
45.3
10,872
Fuel
340
72.8
24,752
Rear seat passengers
Baggage 1 20
94.9
1,898
n/a
Baggage 2
Total ?
2,400 ?
104,706
What now?
Determine whether the plane is safe to fly.

32. Weight and Balance From Pilot Operating Handbook (POH) Safe to fly?
Presentation Name
Course Name
Unit # – Lesson #.# – Lesson Name
Weight and Balance
From Pilot Operating Handbook (POH)
Center of Gravity Moment Envelope
2,500
2,400
2,300
2,200
Safe to fly?
2,100
Barely!
2,000
Loaded Airplane Weight (lb)
1,900
This is a weight and balance chart from the manufacturer often found in a Pilot Operating Handbook (POH). The weight and moment must fall within these boundaries for the airplane to be controllable. If the center of gravity lies too far back, then the aircraft is inclined to pitch up, potentially entering a stall condition. If the center of gravity is too far forward, then the aircraft is inclined to pitch down.
A pilot and supporting ground crew, if applicable, need to perform several important tasks prior to flight. Weight and balance calculations and adjustments are performed by the pilot or supporting ground crew and verified by the pilot. If the ground crew performs this task, then the information is delivered to the pilot on a piece of paper prior to closing the main cabin door. You may have found yourself in the situation on a small commuter aircraft where the flight attendant asks for passengers to change seats. This is to adjust the weight and balance of the aircraft to a more ideal flight condition.
An advanced assignment could be to assign students a more advanced aircraft and then assign seats and position cargo for a safely loaded aircraft.
Note that the change of slope in the upper limit of the graph is because the stability of the aircraft with respect to the weight distribution is more complex than a linear relationship such as applying a load to a wrench. This graph is the result of extensive modeling and testing by aerospace engineers.
1,800
1,700
1,600
1,500 45 50 60 70 80 90
100
110
Loaded Airplane Moment (in.-lb/1000)

33. Effect of Weight on Flight Performance
A heavier gross weight results in a longer takeoff run and shallower climb, and a faster touchdown speed and longer landing roll.

34. Effect of Weight on Flight Performance
The detrimental effects of overloading on performance are not limited to the immediate hazards involved with takeoffs and landings.

35. Effect of Weight on Flight Performance
Overloading has an adverse effect on all climb and cruise performance which leads to overheating during climbs, added wear on engine parts, increased fuel consumption, slower cruising speeds, and reduced range.

36. Effect of Weight on Flight Performance
In some aircraft, it is not possible to fill all seats, baggage compartments, and fuel tanks, and still remain within approved weight or balance limits.
For example, in several popular four-place aircraft, the fuel tanks may not be filled to capacity when four occupants and their baggage are carried.
In a certain two-place aircraft, no baggage may be carried in the compartment aft of the seats when spins are to be practiced.
It is important for a pilot to be aware of the weight and balance limitations of the aircraft being flown and the reasons for these limitations.

37. Effect of Weight on Aircraft Structure
Structural failures which result from overloading may be dramatic and catastrophic, but more often they affect structural components progressively in a manner that is difficult to detect and expensive to repair.

38. Effect of Weight on Aircraft Structure
Habitual overloading tends to cause cumulative stress and damage that may not be detected during preflight inspections and result in structural failure later during completely normal operations.

39. Effect of Weight on Aircraft Structure
In loading an aircraft with either passengers or cargo, the structure must be considered.
Seats, baggage compartments, and cabin floors are designed for a certain load or concentration of load and no more.

40. Effect of Weight on Aircraft Structure
For example, a light plane baggage compartment may be placarded for 20 pounds because of the limited strength of its supporting structure even though the aircraft may not be overloaded or out of CG limits with more weight at that location.

42. Questions / Comments

43. 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.

44. Effect of Load Distribution
The effect of the position of the CG on the load imposed on an aircraft’s wing in flight is significant to climb and cruising performance.

45. Effect of Load Distribution
With forward loading, “nose-up” trim is required in most aircraft to maintain level cruising flight.
Nose-up trim involves setting the tail surfaces to produce a greater down load on the aft portion of the fuselage, which adds to the wing loading and the total lift required from the wing if altitude is to be maintained.

46. Effect of Load Distribution
This requires a higher AOA of the wing, which results in more drag and, in turn, produces a higher stalling speed.

47. Effect of Load Distribution
With aft loading and “nose-down” trim, the tail surfaces exert less down load, relieving the wing of that much wing loading and lift required to maintain altitude.
The required AOA of the wing is less, so the drag is less, allowing for a faster cruise speed.

48. Effect of Load Distribution
The recovery from a stall in any aircraft becomes progressively more difficult as its CG moves aft.
This is particularly important in spin recovery, as there is a point in rearward loading of any aircraft at which a “flat” spin develops.

49. Effect of Load Distribution
A flat spin is one in which centrifugal force, acting through a CG located well to the rear, pulls the tail of the aircraft out away from the axis of the spin, making it impossible to get the nose down and recover.

50. Effect of Load Distribution
To summarize the effects of load distribution:
The CG position influences the lift and AOA of the wing, the amount and direction of force on the tail, and the degree of deflection of the stabilizer needed to supply the proper tail force for equilibrium.

51. Effect of Load Distribution
The aircraft stalls at a higher speed with a forward CG location. This is because the stalling AOA is reached at a higher speed due to increased wing loading.
Higher elevator control forces normally exist with a forward CG location due to the increased stabilizer deflection required to balance the aircraft.

52. Effect of Load Distribution
The aircraft cruises faster with an aft CG location because of reduced drag.
The aircraft becomes less stable as the CG is moved rearward.
A forward CG location increases the need for greater back elevator pressure.

53. Chapter Summary
In order to sustain an aircraft in flight, a pilot must understand how thrust, drag, lift, and weight act on the aircraft.
By understanding the aerodynamics of flight, how design, weight, load factors, and gravity affect an aircraft during flight maneuvers from stalls to high speed flight, the pilot learns how to control the balance between these forces.

54. Chapter Summary
For information on stall speeds, load factors, and other important aircraft data, always consult the AFM/POH for specific information pertaining to the aircraft being flown.