title: Unity aircraft physics
body: <p>I want to make a simple aircraft controller, what looks like little realistic in unity. I watch some video from airplane physics. and make a simple script in unity, but if I start, my plane cant move or if I change drag to zero, it cant lift. I tried to use real data and get it from wiki(F22 Raptor). To my game object, I gave the rigidbody component mass = 19670 kg. 
  Engine thrust = 2 * 116000.0f Newton.</p>
  
  <pre><code>    private void calculateEnginePower()
      {
          EnginePower = engineThrust * ThrottleInput;
      }
  
      private void calculateForces()
      {
          angleOfAttack = Vector3.Angle(Vector3.forward, rb.velocity);
          angleOfAttack = Mathf.Clamp(angleOfAttack, 0, 90);
  
          coefficient = Mathf.Pow(1225.04f * rb.velocity.magnitude, 2) - 1; //M^2-2 where: M is mach.         
  
          if (coefficient &gt; 0.0f)
              coefficientLift = (4 * angleOfAttack) / Mathf.Sqrt(coefficient);
          lift = 1.2754f * 0.5f * Mathf.Pow(rb.velocity.magnitude, 2) * coefficientLift * 78.04f; // densy1.2754 kg/m3, speed m/s , (F22)Wing area: 840 ft² (78.04 m²)
  
          coefficientDrag = 0.021f;
          rb.drag = coefficientDrag * 0.5f * Mathf.Pow(rb.velocity.magnitude,2) * 1.2754f * 78.04f;
  
          rb.AddForce(transform.up * lift);
          rb.AddForce(transform.forward * EnginePower);
      }
  </code></pre>
  
  <p>used these formulas:</p>
  
  <p>for Lift force:
  <a href="https://i.stack.imgur.com/WARcq.png" rel="noreferrer">Lift formula</a>
  for Lift coefficient:
  <a href="https://i.stack.imgur.com/Y4Akw.png" rel="noreferrer">Cl formula</a>
  for Drag:
  <a href="https://i.stack.imgur.com/54IHk.png" rel="noreferrer">Drag formula</a>
  and for Drag coefficient: I used data from wiki too (0.021f).</p>