Airframe

OBJECTIVE
  • To develop the pilot’s understanding of basic aerodynamics.
ELEMENTS
  • Principles of Flight 
  • Airfoils 
  • Forces Acting on the Airplane in Flight 
  • Turning Tendency 
  • Torque, Gyroscopic Precession, Asymmetrical Thrust, Spiraling Slipstream 
  • Airplane Stability 
  • Adverse Yaw 
  • Overbanking Tendency 
  • Loads and Load Factors 
  • Wake Turbulence 

COMPLETION STANDARDS
  • This lesson is complete when the pilot demonstrates a basic understanding of the aerodynamics of maneuvering flight during oral quizzing and completion of homework exercises. 

COMMON ERRORS
  • Aerodynamics Quiz: 
  • Pitch controls [altitude/airspeed], power controls [altitude/airspeed] 
  • [T/F] Maneuvering Speed is the same at all weights 
  • [T/F] As altitude increases, Vy increases 
  • [T/F] As altitude increases, Vx decreases 
  • [T/F] With flaps and/or gear down Vx and Vy remains the same 
  • [T/F] Power changes made hands off only change vertical speed 
  • [T/F] Power changes do not affect trim 
  • [T/F] Painting a control surface does not affect the handling characteristics of an aircraft 
  • [T/F] Aircraft loaded aft of CG limit requires constant elevator pressure to prevent a climb. 
  • [T/F] An aircraft loses airspeed when turned downwind 
  • [T/F] Carrying extra speed on final is a good idea 
  • [T/F] With flaps down, the stalling angle of attack is higher. 
  • [T/F] There’s nothing wrong with using ailerons to recover from a wing drop in a stall. 
  • [T/F] Dihedral rolls the aircraft back to level 
THINGS TO REMEMBER
  • Truths: 
  • Both control both 
  • False. Maneuvering Speed decreases as weight decreases 
  • False. As altitude increases, Vy decreases 
  • False. As altitude increases, Vx increases 
  • False. With flaps and/or gear down, Vx and Vy are both lower 
  • False. Most single-engine piston aircraft will reduce airspeed and start climbing with a power increase and gain airspeed and start descending with a power decrease. It depends on tail structure and engine placement. 
  • False. Propeller slipstream wash change affects trim. 
  • False. Paint can severely change control balance, flutter resistance, and can cause a bad day 
  • False. Aircraft loaded aft of CG limit may still be trimmed for level flight, but has other problems including negative static stability 
  • False. An aircraft will lose groundspeed, not airspeed, when turned downwind. 
  • False. Carrying extra speed on final may not be a good idea as the aircraft will float longer as compared to being at Vref. If the pilot forces the aircraft to land, wheelbarrowing, bouncing, ballooning, and porpoising, and loss of directional control may result 
  • False. With flaps down, the stalling angle of attack is lower, and stalls will start at outboard flap edge, not wing root. 
  • False. Using ailerons to recover from a wing drop in a stall can cause a spin due to adverse yaw. 
  • False. Wing dihedral causes an aircraft to roll away from a slip and does nothing to correct a coordinated shallow turn 
  • Many CFIs do not understand the above. Students can use the above list for selecting a CFI. 
  • Wake Turbulence: A Twin Otter can roll a Piper Arrow. A B737 can roll a B737. A ‘Heavy’ airliner can force a light aircraft out of the sky from 1000’ AGL. Refer to NTSB report LAX00LA035 for more examples. 

STUDY
  • “Pilot’s Handbook of Aeronautical Knowledge” Ch. 2, 3, & 4 
  • FAA’s “Wake Turbulence Training Aid” 
  • Kershner’s “Advanced Pilot Manual” 
  • “Aerodynamics for Naval Aviators” 
  • “Aeronautical Information Manual” Ch. 7