Lecture Notes: Climb Procedure and Performance Characteristics

Introduction

• Instructor: Grant
• Focus: Understanding climb procedures and performance characteristics in aviation.

Climb Phase in Flight

• Begins after takeoff and reaching screen height.
• Continues to cruising altitude but can occur at various stages (e.g., after a go-around).

Climb Performance Factors

Angle of Climb

• Defined by: Excess thrust over weight.
• Key Factors:
  • Larger thrust and lower drag increase climb angle.
  • Equation: (\sin \theta = \frac{\text{Excess thrust}}{\text{Weight}})
  • Example: A 1000N excess thrust on a 10,000N aircraft results in a 5.7-degree climb angle.
• Trigonometry: Small angles, (\sin \theta \approx \text{gradient}) (vertical/horizontal)

Climb Gradient

• Equals angle of climb, (\sin \theta = \text{Climb Gradient} = \frac{\text{Thrust} - \text{Drag}}{\text{Weight}})
• Speed for Best Angle (VX): Occurs at maximum excess thrust.
  • Jets: VMD = VX (speed for minimum drag)
  • Propeller Aircraft: Close to speed for minimum power (VMP)

Factors Affecting Climb Angle

• Mass: More mass leads to smaller climb angle.
• Configuration: Flaps and gear increase drag, reducing climb gradient.
• Altitude/Temperature: Increase reduces thrust, decreasing climb gradient.
• Engine Failure: Results in significant loss of thrust and excess thrust.
• Wind: Affects flight path angle, not climb angle.

Rate of Climb

• Defined by: Excess power over weight.
• Key Factors:
  • Depends on both angle and true airspeed.
  • Equation: (\text{Rate of Climb} = \frac{\text{Excess Power}}{\text{Weight}})

Speed for Best Rate (VY)

• Occurs at maximum excess power.
  • Jets: Faster than VMD, equal to VX
  • Propeller Aircraft: Between VMP and VX

Factors Affecting Rate of Climb

• Mass: Higher weight increases required power, reducing rate.
• Configuration: Increased drag shifts power required curve upwards.
• Altitude/Temperature: Reduces thrust, decreasing excess power.
• Wind: Does not affect rate of climb.

Transition from Indicated Airspeed to Mach Number

• Indicated Airspeed (IAS): As altitude increases, true airspeed (TAS) and Mach number rise.
• Changeover Altitude: Shift from constant IAS to Mach number to avoid exceeding structural limits.

Summary

• Climb Gradient: (\text{Excess thrust over weight})
• Rate of Climb: (\text{Excess power over weight})
• Optimize climb by maximizing excess thrust and power, minimizing weight and drag.
• Wind influences flight path angle, not actual climb angle or rate.
• Transition from IAS to Mach number ensures safety during climb.