What is TMS on Boeing 737? (Thrust Management System)

The Thrust Management System (TMS) is an integral part of the Boeing 737-800 aircraft, which is used to control and manage the engine thrust during various phases of flight. It plays a crucial role in ensuring optimal performance and fuel efficiency. This article will delve into the intricacies of the Thrust Management System and its significance in the operations of the Boeing 737-800.

Functionality of the Thrust Management System

The Thrust Management System on the Boeing 737-800 is responsible for automatically controlling engine thrust based on the inputs received from various aircraft systems, such as the Flight Management Computer (FMC) and the Autothrottle System. Its primary objective is to optimize performance and fuel efficiency while ensuring the aircraft operates within safe limits.

The TMS adjusts the engine thrust continuously throughout the flight to meet the desired speed, climb rate, or descent rate. It takes into account factors such as aircraft weight, altitude, temperature, and airspeed to calculate the most efficient thrust setting required for each phase of flight. By doing so, it helps minimize fuel consumption and reduce operating costs for airlines.

Key Components of the Thrust Management System

The Thrust Management System comprises several key components that work together to ensure smooth and efficient engine performance. These components include:

  • Engine Pressure Ratio (EPR): The EPR sensor measures the ratio of exhaust gas pressure to ambient pressure and provides vital information to the TMS.
  • Engine Bleed Air: The TMS utilizes the engine bleed air system to regulate the flow of compressed air to various systems, including the anti-ice system and environmental control system.
  • Autothrottle System: The Autothrottle System is closely integrated with the TMS and helps control engine thrust based on pilot inputs and the guidance provided by the Flight Management Computer.
  • Throttle Quadrant: The Throttle Quadrant consists of levers that allow the pilot to manually control the engine thrust. The TMS works in conjunction with these levers to ensure the desired thrust setting is maintained.

These components work seamlessly together to provide precise control over engine thrust, resulting in optimized performance and fuel efficiency.

Advantages of the Thrust Management System

The implementation of the Thrust Management System offers several advantages for both pilots and airlines operating the Boeing 737-800:

1. Enhanced Safety: The TMS ensures the engines operate within safe limits, preventing over-speed or over-temp conditions that could lead to engine damage or failure. It provides critical engine protection and assists in handling abnormal situations.

2. Fuel Efficiency: The Thrust Management System continuously adjusts the engine thrust to maintain optimal performance while reducing fuel consumption. It takes into account various factors, such as aircraft weight and altitude, to calculate the most efficient thrust setting.

3. Reduced Workload for Pilots: The TMS automates the thrust control process, reducing the workload for pilots during flight operations. It allows them to focus on other critical tasks and enhances overall flight safety.

4. Cost Savings: By optimizing engine thrust and fuel consumption, the Thrust Management System helps airlines reduce operating costs significantly. This is especially crucial in today’s competitive aviation industry, where fuel expenses account for a significant portion of an airline’s budget.


The Thrust Management System plays a vital role in the operations of the Boeing 737-800 aircraft. It ensures optimal engine performance, fuel efficiency, and safety throughout various phases of flight. By automating the control of engine thrust, it reduces pilot workload and allows them to focus on other critical tasks. The implementation of the TMS has proven to be a significant advancement in aviation technology, offering numerous benefits for airlines and passengers alike.

For more information on the Thrust Management System and its functionalities, you can refer to the official Boeing website.

For More: What is HUD on Boeing 737? (Head-Up Display)