What is VSO in Aviation? (Stall Speed In Landing Configuration)

Aviation is an intricate field that encompasses a wide range of technical terms and concepts. One such term is the stall speed in landing configuration, commonly abbreviated as Vso. Understanding Vso is crucial for pilots and aviation enthusiasts as it directly relates to the safe operation and control of an aircraft during landing maneuvers. In this article, we will delve into the details of stall speed in landing configuration, its significance, and how it affects flight safety and performance.

1. Exploring Stall Speed in Landing Configuration (Vso)

The stall speed in landing configuration, or Vso, refers to the minimum speed at which an aircraft can maintain controlled flight just before it stalls. This specific configuration is crucial as it simulates the landing phase, ensuring that the aircraft operates within safe limits during landing approach and touchdown.

Vso is influenced by various factors, including the aircraft’s weight, configuration (such as flaps and landing gear position), and atmospheric conditions (such as air density and temperature). These factors directly impact the lift and drag forces acting on the aircraft’s wings, determining the minimum speed required to generate sufficient lift to maintain controlled flight.

It is important to note that stall speed in landing configuration, or Vso, is distinct from other stall speeds such as Vs1g, Vmc, and Vne, which are relevant to different flight phases and conditions. Vso specifically addresses the aircraft’s behavior during landing, ensuring that it can safely approach the runway and make a smooth touchdown.

2. Significance and Impact on Flight Safety

The stall speed in landing configuration (Vso) plays a critical role in ensuring flight safety during landing maneuvers. By understanding and adhering to Vso limits, pilots are able to maintain control over the aircraft and avoid dangerous situations.

Operating an aircraft below Vso during landing can result in a aerodynamic stall, where the wings reach a critical angle of attack and lose the ability to produce sufficient lift. This can lead to a rapid loss of altitude, reduced controllability, and potential loss of control. To prevent these risks, pilots must carefully manage their approach and touchdown speed, ensuring that they remain above Vso to maintain control and stability.

In addition to flight safety, understanding Vso also impacts various operational aspects of an aircraft. It helps determine the appropriate aircraft performance data, such as landing distances, touchdown speeds, and approach procedures. These factors are crucial for safe and efficient landing operations, especially in varying weather conditions and runway lengths.

3. Factors Affecting Stall Speed in Landing Configuration (Vso)

Stall speed in landing configuration (Vso) is influenced by several key factors that pilots must consider during landing operations. These factors include:

  • Aircraft Weight: The heavier the aircraft, the higher the stall speed. This is due to the increased lift required to support the additional weight during landing.
  • Flap Configuration: The position of flaps affects the aircraft’s lift and drag characteristics. Extending flaps increases lift and drag, reducing the stall speed. Different flap settings have specific Vso values, which pilots must be aware of for their respective aircraft.
  • Landing Gear Position: The position of the landing gear also impacts the aircraft’s drag and lift characteristics. Extending or retracting the landing gear alters the airflow around the aircraft, influencing the stall speed in landing configuration.
  • Atmospheric Conditions: Air density, temperature, and humidity affect an aircraft’s aerodynamic performance. Higher air density and lower temperatures decrease an aircraft’s stall speed, while the opposite conditions can increase it.

Pilots must account for these factors and ensure they operate their aircraft within the recommended Vso limits provided by the manufacturer. These limits are typically documented in the aircraft’s flight manual and serve as a crucial reference for safe landing operations.


The stall speed in landing configuration (Vso) is an essential concept in aviation that pilots need to understand and apply during landing maneuvers. By adhering to Vso limits, pilots ensure the safe operation of their aircraft, maintain control and stability, and mitigate the risks associated with aerodynamic stalls. Understanding the factors affecting Vso, such as aircraft weight, flap configuration, landing gear position, and atmospheric conditions, allows pilots to make informed decisions during landing operations and optimize flight safety. By prioritizing Vso and its significance, pilots uphold the highest standards of aviation safety, ensuring smooth and secure landings for passengers and crew alike.

For more information about stall speed in landing configuration, you can refer to the FAA Pilot’s Handbook of Aeronautical Knowledge, which provides comprehensive guidance and insights into various aviation topics, including Vso and its applications.

For More: What is MMD in Aviation? (Moving Map Display)