What is TGT on Boeing 737? (Turbine Gas Temperature)

The Turbine Gas Temperature (TGT) is a critical parameter in the operation of the Boeing 737 aircraft. It refers to the temperature of the gas flowing through the aircraft’s turbine engines. The TGT is an important factor that affects the engine’s performance, efficiency, and overall safety.

Managing and monitoring the TGT is crucial for the aircraft’s operation, as exceeding the permissible limits can lead to engine damage or failure. In this article, we will dive deeper into the details of Turbine Gas Temperature and its significance in ensuring the safe and efficient operation of the Boeing 737 aircraft.

Why is Turbine Gas Temperature Important?

The Turbine Gas Temperature plays a critical role in the performance and efficiency of the turbine engines on the Boeing 737 aircraft. It directly affects the engine’s thrust generation, fuel consumption, and overall engine health.

To better understand the importance of TGT, let’s take a closer look at its impact on each aspect of the engine’s operation:

1. Thrust Generation

Turbine Gas Temperature has a direct influence on the thrust generated by the engine. In simple terms, the higher the TGT, the greater the thrust produced. However, it is crucial to maintain the TGT within safe limits to prevent engine damage. The engine’s thrust is achieved by the expansion of gases through the turbine section, and controlling the TGT ensures that this process occurs efficiently and safely.

Excessive TGT can cause the turbine blades to overheat, leading to material degradation and potentially catastrophic failures. On the other hand, insufficient TGT can result in reduced thrust output and inefficient engine performance. Therefore, monitoring and managing the TGT effectively is essential for maintaining optimal thrust generation and ensuring the safe operation of the Boeing 737 aircraft.

2. Fuel Consumption

Turbine Gas Temperature also plays a crucial role in determining the fuel consumption of the Boeing 737 aircraft. The TGT directly affects the efficiency of the combustion process within the engine, which, in turn, impacts the amount of fuel required to generate thrust.

Higher TGT values generally result in improved fuel efficiency, as they indicate more efficient combustion. The hotter gas temperatures allow for better expansion and energy extraction from the fuel, translating into increased thrust per unit of fuel consumed. However, there is an upper limit to the TGT, beyond which the fuel consumption may increase due to excessive exhaust gas temperatures.

3. Engine Health and Safety

The Turbine Gas Temperature is a crucial parameter when it comes to maintaining the health and safety of the Boeing 737 engines. Engine components, particularly the turbine blades, are designed to withstand specific temperature limits.

Exceeding these temperature limits can lead to issues such as corrosion, erosion, material fatigue, and even catastrophic failures. The TGT is continuously monitored and controlled to ensure that the engine components operate within their design limits and maintain their structural integrity.

Furthermore, the TGT is closely monitored during various phases of flight, such as takeoff, climb, cruise, and descent. Monitoring TGT allows maintenance crews to detect any abnormal temperature variations that may indicate potential engine issues or malfunctioning components. Early detection of such anomalies helps prevent more significant problems and ensures the safety of the passengers and the aircraft.

How is Turbine Gas Temperature Monitored and Controlled?

Monitoring and controlling the Turbine Gas Temperature on the Boeing 737 aircraft is a sophisticated process that involves various sensors, instruments, and control mechanisms.

The TGT is typically monitored using thermocouples installed at strategic locations within the turbine engine assembly. These thermocouples measure the temperature of the gas flowing through the engine, providing real-time data to the aircraft’s Engine Indication and Crew Alerting System (EICAS).

The EICAS displays the TGT values to the flight crew, allowing them to monitor the temperature and take appropriate actions if necessary. In the event of TGT exceeding the safe limits, the EICAS provides warnings and alerts to the crew, enabling them to take corrective measures or initiate engine shutdown procedures.

The TGT is controlled through the engine’s fuel management system. The fuel control unit regulates the fuel flow into the combustion chamber, thereby controlling the gas temperature. By adjusting the fuel flow rate, the TGT can be effectively managed and maintained within the acceptable range for safe and efficient engine operation.

The Boeing 737 aircraft also incorporates an Automatic Thrust Restoration (ATR) feature, which acts as an additional layer of safety. In the event of an engine flameout or sudden power loss, the ATR system automatically adjusts the fuel flow to restore thrust and ensure continued operation of the engine.


The Turbine Gas Temperature (TGT) is a critical parameter in the operation of the Boeing 737 aircraft. It significantly impacts the engine’s performance, efficiency, and overall safety. Maintaining the TGT within safe limits is crucial to prevent engine damage and ensure optimal thrust generation and fuel consumption.

Monitoring and controlling the TGT involves sophisticated sensors, instruments, and control mechanisms. The EICAS provides real-time TGT data to the flight crew, enabling them to take appropriate actions. The engine’s fuel management system and Automatic Thrust Restoration feature play integral roles in managing the TGT and ensuring the safe operation of the Boeing 737 aircraft.

The Turbine Gas Temperature remains a critical aspect of aviation, and continuous advancements in engine technology and monitoring systems contribute to safer and more efficient operations.

For More: What is MBPS on Boeing 737? (Megabits Per Second)