V-Speeds

Updated at: 2025-12-01 10:36
procedures
V-speeds are standardized airspeeds used in aviation to describe key performance limits, safe operating ranges, and recommended speeds for different phases of flight. Knowing and applying V-speeds correctly is essential for safe aircraft operation, especially during takeoff, climb, approach, and landing.<\/b>

1. Definition of V-Speeds

In aviation, V-speeds are predefined airspeeds that represent important performance points or limitations of an aircraft. The letter "V" comes from the French word "vitesse," meaning speed. Each V-speed is denoted by a subscript (for example, VR, VY, VFE) and is defined by certification standards such as those from the Federal Aviation Administration (FAA) and the European Union Aviation Safety Agency (EASA).
V-speeds are usually expressed as indicated airspeed (IAS) on the airspeed indicator and are published in the aircraft flight manual (AFM) or pilot’s operating handbook (POH). Many critical V-speeds are marked on the airspeed indicator using colored arcs and radial lines to help pilots quickly recognize safe operating ranges.
Although some common V-speeds are used across many aircraft types, their exact numerical values are specific to each aircraft model and configuration, and often depend on weight, flap setting, and other conditions.

2. Purpose of V-Speeds

The primary purpose of V-speeds is to provide clear, standardized reference speeds that support safe and predictable aircraft performance. They allow pilots to make quick decisions under varying conditions without having to calculate performance from first principles during flight.
V-speeds serve several key functions:
  • Safety margins: They define safe operating limits that reduce the risk of stall, structural damage, or loss of control.
  • Performance optimization: They indicate speeds that give the best climb, range, or endurance performance.
  • Standardization: They provide a common language for pilots, instructors, and air traffic control (ATC) when discussing performance and procedures.
  • Certification compliance: They ensure the aircraft is flown within the limits established during certification testing.
By flying the correct V-speeds at the correct times, pilots maintain adequate control margins, protect the airframe from excessive loads, and achieve the performance needed to safely clear obstacles, handle engine failures, and complete takeoffs and landings within available runway distances.

3. Use of V-Speeds in Aviation

V-speeds are used throughout all phases of flight, but they are especially critical during takeoff, climb, approach, and landing, when the aircraft is close to the ground and has less time and altitude available to recover from errors or malfunctions.

3.1 Commonly Used V-Speeds and Their Meanings

The following list summarizes some of the most commonly referenced V-speeds for student pilots. Exact values and applicability vary by aircraft type and configuration, so the AFM/POH is always the final reference.
  • VS – Stall speed (clean configuration): The minimum steady flight speed at which the aircraft is controllable in a specified configuration, usually with flaps and gear up.
  • VSO – Stall speed in landing configuration: The minimum steady flight speed with landing configuration (usually flaps and gear down).
  • VX – Best angle of climb speed: The speed that gives the greatest altitude gain per unit of horizontal distance; used to clear obstacles after takeoff.
  • VY – Best rate of climb speed: The speed that gives the greatest altitude gain per unit of time; used to climb efficiently to a higher altitude.
  • VFE – Maximum flap extended speed: The highest speed at which flaps may be extended safely.
  • VNO – Maximum structural cruising speed: The upper limit of the normal operating range; above this speed, only smooth air operations are recommended.
  • VNE – Never exceed speed: The speed that must never be exceeded in any operation; exceeding VNE may cause structural damage or failure.
  • VA – Design maneuvering speed: The maximum speed at which full, abrupt control deflections can be made without exceeding structural limits (at a specified weight).
  • VR – Rotation speed: For takeoff, the speed at which the pilot initiates nose-up pitch to lift off.
  • V1 – Takeoff decision speed: For multi-engine transport aircraft, the maximum speed during takeoff at which a rejected takeoff can be initiated and the aircraft stopped within the remaining runway.
  • V2 – Takeoff safety speed: For multi-engine transport aircraft, the speed that provides a safe climb gradient with one engine inoperative after takeoff.
  • VREF – Reference landing approach speed: A reference final approach speed, typically based on a multiple of stall speed in landing configuration, used for landing performance calculations.

3.2 Phases of Flight Where V-Speeds Are Applied

Pilots use different sets of V-speeds in each phase of flight. The following overview focuses on how a student pilot will typically apply them in day-to-day operations.

3.2.1 Takeoff and Initial Climb

During takeoff, V-speeds help ensure that liftoff and initial climb are performed safely and predictably. In light single-engine aircraft, the most relevant speeds are VR, VX, and VY. In multi-engine transport aircraft, V1, VR, and V2 are critical for both performance and decision-making.
  1. Acceleration: The aircraft accelerates from standstill; the pilot monitors airspeed increase.
  2. V1 (transport aircraft): Before V1, an engine failure normally leads to a rejected takeoff; after V1, the takeoff is continued.
  3. VR (all fixed-wing aircraft with defined rotation): At VR, the pilot applies gentle back-pressure to rotate and lift off.
  4. V2 (multi-engine transport aircraft): After liftoff, the aircraft should reach at least V2 by 35 ft above the runway to ensure adequate climb performance with one engine inoperative.
  5. VX and VY (light aircraft): After a safe height is achieved, the pilot selects VX to clear obstacles or VY to climb efficiently.

3.2.2 Cruise and Maneuvering

In cruise and during maneuvers, V-speeds protect the aircraft from structural overload and provide guidance for turbulence and training maneuvers.
  • VNO: Cruise should normally be below or around VNO, especially in rough air.
  • VNE: Must never be exceeded in any phase of flight.
  • VA: In turbulence or when practicing steep turns and stalls, flying at or below VA reduces the risk of structural damage from abrupt control inputs.

3.2.3 Approach and Landing

On approach and landing, V-speeds help the pilot avoid stall while also respecting flap and gear limitations. For student pilots, VFE, VS, VSO, and VREF (or published approach speeds) are particularly important.
  1. Flap extension: The pilot extends flaps only below VFE to avoid flap damage.
  2. Approach speed: The pilot flies a recommended approach speed, often related to VREF or a multiple of VSO, to maintain a safe margin above stall.
  3. Final approach and flare: Speeds are gradually reduced while maintaining control; the aircraft passes through speeds closer to VSO during the flare and touchdown.

4. Operational Considerations for V-Speeds

Using V-speeds correctly requires understanding that they can change with weight, configuration, and environmental conditions. Student pilots should always refer to the AFM/POH performance charts rather than memorizing values without context.

4.1 Factors Affecting V-Speeds

Several factors influence the appropriate V-speeds for a given flight:
  • Aircraft weight: Heavier weights generally increase stall speeds and may change VA, V1, VR, and V2.
  • Configuration: Flap and landing gear positions affect stall speeds and maximum allowable speeds (such as VFE and gear speeds).
  • Center of gravity (CG): Extreme forward or aft CG positions can affect handling and stall characteristics.
  • Density altitude: High temperature, high elevation, and low pressure reduce performance; while indicated V-speeds remain the same, true airspeed and ground run increase.
  • Runway conditions: Contaminated or short runways influence how conservatively V-speeds are applied, especially for transport aircraft.

4.2 Practical Use for Student Pilots

For a student pilot in a light training aircraft, V-speeds are typically introduced in stages. Initially, emphasis is placed on a small set of essential speeds, with more detail added as training progresses.
  1. Memorize key speeds: Learn a core group such as VS, VSO, VX, VY, VFE, VA, and normal approach speeds for the training aircraft.
  2. Use the airspeed indicator markings: Relate the white arc, green arc, yellow arc, and red line to VSO, VS, VNO, and VNE.
  3. Brief V-speeds before takeoff and landing: State the relevant speeds aloud during pre-takeoff and pre-landing briefings to reinforce correct use.
  4. Adjust for weight: When applicable, use POH tables or charts to adjust VA and other speeds for actual takeoff weight.
  5. Cross-check performance: After each takeoff and landing, compare observed performance with expected performance based on V-speeds and conditions.

4.3 Limitations and Cautions

V-speeds are powerful tools, but they are not a substitute for overall situational awareness and good judgment. Some important cautions include:
  • Certification assumptions: Many V-speeds are based on test conditions that may differ from real-world operations (for example, test pilots, new aircraft, and ideal runway conditions).
  • Instrument accuracy: The airspeed indicator may have position and instrument errors; indicated V-speeds are approximations of true aerodynamic conditions.
  • Pilot technique: Poor rotation or flare technique can negate the benefits of flying the correct V-speeds.
  • Environmental variability: Wind shear, gusts, and turbulence can require additional speed margins beyond published values.

5. Example V-Speeds for Cessna 172 Skyhawk and Boeing 747

The following examples illustrate typical V-speeds for a common training aircraft, the Cessna 172 Skyhawk, and a large transport-category aircraft, the Boeing 747. These values are approximate and for training reference only. Always refer to the specific aircraft’s AFM/POH or flight crew operating manual (FCOM) for operational use.

5.1 Typical V-Speeds for a Cessna 172 Skyhawk

Values below are representative for a Cessna 172S Skyhawk at typical training weights and standard conditions. They may differ for other 172 variants or specific loading conditions.
V-SpeedDescriptionApproximate Value (KIAS)
VSStall speed, clean (flaps up)~48 KIAS
VSOStall speed, landing configuration (full flaps)~40 KIAS
VXBest angle of climb~62 KIAS
VYBest rate of climb~74 KIAS
VFEMaximum flap extended speed (10°)110 KIAS
Maximum flap extended speed (20°–30°)85 KIAS
VADesign maneuvering speed (max weight)~105 KIAS
VNOMaximum structural cruising speed129 KIAS
VNENever exceed speed163 KIAS
Normal approachFinal approach speed (full flaps)~60–65 KIAS
Example: After takeoff in a Cessna 172, a student pilot might climb at VX (about 62 KIAS) to clear nearby trees, then transition to VY (about 74 KIAS) to continue climbing efficiently to the traffic pattern altitude.

5.2 Typical V-Speeds for a Boeing 747

For a large transport aircraft such as the Boeing 747, V-speeds are calculated for each takeoff and landing based on weight, configuration, and environmental conditions. The following values are approximate examples for a Boeing 747-400 at a representative takeoff weight. They are shown only to illustrate the scale and use of V-speeds in heavy jet operations.
V-SpeedDescriptionApproximate Example Value (KIAS)
V1Takeoff decision speed~150–170 KIAS (varies with weight and runway)
VRRotation speed~160–180 KIAS
V2Takeoff safety speed (one engine inoperative climb)~170–190 KIAS
VREFReference landing approach speed (full landing flaps)~145–160 KIAS
VFEMaximum flap extended speeds (depending on flap setting)Typically 180–260 KIAS across flap settings
VA / turbulence penetrationRecommended turbulence penetration speedTypically around 270–290 KIAS (or Mach 0.78–0.80 at altitude)
Example: On a Boeing 747 takeoff, the crew will brief the calculated V1, VR, and V2 speeds before departure. During the takeoff roll, if an engine fails before V1, the takeoff is rejected; if it fails after V1, the takeoff is continued, and the aircraft is flown at or above V2 to ensure adequate climb performance.

6. Summary

V-speeds are standardized reference airspeeds that define key performance points and limitations for each aircraft type. For student pilots, understanding what each V-speed represents, when to use it, and how it is affected by weight and configuration is a fundamental part of safe flying. Whether in a Cessna 172 or a Boeing 747, correct use of V-speeds supports safe takeoff, climb, cruise, approach, and landing operations.