Study Notes on Aircraft Turns, Load Factor, and Spiral Dives

Overview of Turns and Load Factor in Aircraft

• The load factor is crucial for understanding turns in aviation.
  • Definition of Load Factor: The ratio of the lift of an aircraft to its weight.

Forces Acting on an Airplane in a Turn

• An airplane in flight experiences two primary forces:

  • Weight: The gravitational force pulling the aircraft downward.
  • Lift: The aerodynamic force acting upward to counteract weight.

• In a level flight, the lift must equal the weight:
  Lift = Weight

Effects of Turns on Lift and Load Factor

• During a turn, the required lift does not match the weight of the aircraft when turning at angles like 45 degrees.

  • Gentle Turn: Ranges from 0 to 15 degrees.
  • Medium Turn: Ranges from 15 to 30 degrees.
  • Sharp Turn: 45 degrees or more.

• In a turn, less vertical lift is available:

  • A horizontal component of lift assists in executing the turn while maintaining equilibrium.
  • However, this reduces the vertical lift component needed against weight.

Procedures for Managing Turns

• To maintain altitude during steep turns, the pilot must:
  • Pull Up: This action increases vertical lift to counteract the weight when in a turn.
  • If only pulling up, airspeed may decrease due to increased drag.

Understanding Load Factor Increase in Turns

• As the degree of turn increases, the load factor also increases, consequently affecting stall speed:

  • At 40 degrees, the load factor increases to 13%.
  • At 60 degrees, it increases to 40%.
  • At 75 degrees, it can reach 100%.

• Stall Speed Requirements: Stall speeds at various weights need to be maintained to ensure flight safety:

  • Typical stall speed at full weight: approximately 47 knots.

Speed Maintenance and Trim

• To sustain airspeed during turns and avoid stalling:
  • Pilots may use elevator trim to relieve control pressure.
  • Leveling Out: In a turn context, leveling out at 22.5 degrees is necessary for stability.

Forces in Turns

• When turning, a pilot experiences:
  • Centripetal Force: Required to keep the aircraft in a circular path.
  • Centrifugal Force: The perceived force pushing away from the turn.
  • When these forces act together, they affect drag and require power adjustments.

Power Management in Turns

• Key procedures during a turn include:
  1. Look around for safety checks.
  2. Initiate the turn while maintaining optimal degrees of bank.
  3. At 30 degrees of bank, pull up and add power to counteract load factors.
  4. Complete a full 360-degree turn, using back pressure to maintain lift.
  5. To exit, reduce power gradually while rolling out of the turn at about 30 degrees.

Concept of Spiral Dive

• Spiral Dive: A dangerous scenario caused by neglecting control inputs or excessive bank angles.
  • Indicates a rapid descent with inappropriate back pressure resulting.
  • Increased angle of descent correlates with increased airspeed, possibly leading to structural failure if beyond safety limits.

Recovery from Spiral Dives

• Procedures for recovery:

  1. Power first: Reduce throttle to idle to reduce speed risk.
  2. Roll wings level to regain control.
  3. Pull out of the dive steadily to avoid structural stress.

• Note on Aircraft Flexibility:

  • Aircraft can twist but not flex and roll simultaneously without risking structural damage.

Emphasis on Safety Measures

• Procedures in aviation are critical; pilots are trained to follow structured responses to avoid accidents.
  • Exercises like spiral dives are for dual instruction only, emphasizing the need for instructor guidance during high-risk maneuvers.