What is K OR KTS on Boeing 737? (Knots)

When it comes to aviation, there are several important terms and measurements that pilots and aviation enthusiasts need to be familiar with. One such measurement is knots, often abbreviated as K or Kts. In the context of aviation, knots refer to the speed of an aircraft. In this article, we will explore what knots are in the context of the Boeing 737-800 aircraft, one of the most popular and widely used aircraft in the world.

The Application of Knots on Boeing 737

On the Boeing 737-800, knots are used throughout various stages of flight and are an essential part of the aircraft’s operations. From takeoff to cruising and landing, pilots rely on knots to ensure a smooth and safe journey. Let’s take a closer look at how knots are utilized in different aspects of the Boeing 737-800’s flight:


During takeoff, the aircraft needs to reach a certain speed to generate enough lift for it to become airborne. The takeoff speed of the Boeing 737-800 varies depending on factors such as the weight of the aircraft, wind speed, runway length, and temperature. This speed is expressed in knots and is known as the “V1” speed. V1 represents the maximum speed at which the pilot can still abort the takeoff if necessary.

Once the aircraft is in the air, it continues to climb at a specific rate indicated in knots. This climb rate is known as the “Rate of Climb,” and it determines how quickly the aircraft gains altitude. The rate of climb can be influenced by various factors, including the aircraft’s weight, engine power, and environmental conditions. Maintaining the desired climb rate is crucial for the Boeing 737-800’s climb phase.


When the aircraft reaches its desired altitude, it enters the cruising phase of the flight. Cruising speed is measured in knots and represents the speed at which the aircraft maintains a steady flight. The cruising speed of the Boeing 737-800 is typically around 440 knots, depending on factors such as altitude and distance. This speed allows the aircraft to cover long distances efficiently and is influenced by various factors such as air traffic control instructions, weather conditions, and fuel economy considerations.

In addition to the cruising speed, the Boeing 737-800 also has a maximum operating speed known as the “VMO” speed. VMO is expressed in knots and represents the highest speed at which the aircraft can safely operate without exceeding its structural limits. It is important for pilots to adhere to this speed limit to ensure the integrity of the aircraft and the safety of everyone on board.


During the landing phase, the aircraft gradually reduces its speed in preparation for touchdown. The approach speed, measured in knots, is the speed at which the aircraft maintains while descending towards the runway. The exact approach speed for the Boeing 737-800 depends on various factors such as aircraft weight, wind conditions, and runway length. It is crucial for pilots to manage the aircraft’s speed carefully during the landing phase to ensure a smooth and safe touchdown.

After touchdown, the aircraft slows down using its brakes and spoilers. The deceleration rate is expressed in knots and determines how quickly the aircraft comes to a complete stop. It is essential for pilots to have precise control over the deceleration rate to ensure a safe landing and smooth taxiing off the runway.


Knots play a vital role in the operations of the Boeing 737-800 aircraft, from takeoff to landing. Pilots rely on these measurements to ensure safe and efficient flights. Whether it’s the takeoff speed, climb rate, cruising speed, or landing approach speed, knots provide valuable information to pilots, enabling them to make informed decisions about the aircraft’s performance and safety. Understanding knots is essential for anyone interested in aviation and the fascinating world of flying.

To learn more about the Boeing 737-800 and its capabilities, you can visit the official Boeing website here.

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