Overview
This lesson covers essential airspeeds (V-speeds), the airspeed indicator, and color-coded speed ranges relevant for safe aircraft operation in preparation for exams and flight checks.
Types of Airspeed
- Indicated Airspeed (IAS): The speed shown on the airspeed indicator; primarily used for V-speeds.
- Calibrated Airspeed (CAS): IAS corrected for instrument and position error, found in the Pilot Operating Handbook (POH).
- True Airspeed (TAS): CAS adjusted for altitude and temperature; increase CAS by 2% per 1,000 feet for a quick estimate.
- Ground Speed (GS): The actual speed over the ground, affected by wind.
Key V-Speeds
- Vx: Best angle of climb airspeed, provides most altitude in shortest distance (used to clear obstacles).
- Vy: Best rate of climb airspeed, provides most altitude in shortest time (used after clearing obstacles).
- Va: Maneuvering speed, the fastest speed to avoid structural damage during abrupt control inputs or turbulence.
- Vs0: Stall speed in landing configuration (gear/flaps down), lower limit of the white arc.
- Vfe: Maximum flap extended speed, upper limit of the white arc.
- Vs1: Stall speed with gear/flaps up, lower limit of the green arc.
- Vno: Maximum structural cruising speed, upper limit of the green arc and lower limit of the yellow arc.
- Vne: Never exceed speed, marked by a red line at the end of the yellow arc.
- Vlo: Maximum speed for extending/retracting landing gear on retractable gear aircraft.
- Vle: Maximum speed for flying with landing gear extended.
Airspeed Indicator Markings
- Zero Airspeed Marker: Should read zero when stationary; check during run-up and takeoff roll.
- White Arc: Flap operating range (Vs0 to Vfe).
- Green Arc: Normal operating range (Vs1 to Vno).
- Yellow Arc: Caution range, only use in smooth air (Vno to Vne).
- Red Line: Vne, never exceed speed.
Key Terms & Definitions
- V-speed — Designated airspeeds critical for different phases of flight, named by a "V" for velocity.
- Maneuvering speed (Va) — Maximum speed for full, abrupt control input without structural damage.
- Stall speed (Vs0, Vs1) — The minimum speed at which the aircraft can maintain level flight in various configurations.
Action Items / Next Steps
- Review V-speeds and their corresponding airspeed indicator markings.
- Practice identifying V-speeds and arcs on an actual or simulated airspeed indicator.
- Prepare to discuss calculation of true airspeed in future lessons.