Alpha hinge

{
  "id": "MLC-T-IND-000173",
  "term": "Alpha hinge",
  "field": "Industrial and trades",
  "definition": "A mechanical pivot that connects a helicopter rotor blade to the rotor hub, permitting the blade to flap up and down. This vertical movement, known as the flapping angle or alpha angle, is necessary to compensate for the dissymmetry of lift experienced in forward flight. The advancing blade flaps up to decrease its angle of attack, while the retreating blade flaps down to increase its angle of attack, balancing the lift across the entire rotor disc.",
  "subject": "Aviation maintenance",
  "references": [
    "articulation de traînée (Office québécois de la langue française)"
  ],
  "translations": {
    "de": "Alpha-Scharnier",
    "es": "bisagra alfa",
    "fr": "articulation alpha"
  },
  "url": "https://mlchart.com/terminology/industrial/alpha-hinge/"
}