Aircraft Speed

• Aircraft speed is measured in knots.
  • 1 knot = 1 nautical mile per hour = 1.852 km/h.

Speed Parameters

1. Selected Speed

   • The target speed set by the pilot or flight system.

2. Speed Trend Arrow

   • The tip of the arrow indicates the projected speed after 10 seconds if the aircraft’s acceleration remains unchanged.

3. Indicated Airspeed (Current Speed)

   • The aircraft’s current speed as measured by onboard instruments.

4. Maximum Allowable Speed (Lower Edge of the Red-Black Zone)

   • Determined as the minimum of:
     • Maximum permissible airspeed or Mach number.
     • Speed limits with deployed landing gear.
     • Speed limits based on flap extension angles.

5. Lower Edge of the Yellow Zone

   • Indicates the speed that allows maneuvering with a load factor up to 1.3g (e.g., up to 40 degrees of bank) without the risk of high-altitude buffeting.
   • This indication typically appears at higher altitudes and with relatively high aircraft weight.

6. Selected Speed Marker

   • Shows the speed selected on the autopilot or flight system.

7. For Speeds Above 0.4M:

   • The current Mach number is displayed (the ratio of the aircraft’s speed to the speed of sound).