Model-Based Fault Identification of Fighter Aircraft’s Environmental Control System

The Environmental Control System (ECS) maintains conditions suitable for a crew inside aircrafts cabin. ECS controls temperature, pressurizes cabin, provides breathing air and removes excess air humidity. All ECS functionalities have great impact on pilots’ safety, performance and comfort. Furthermore, aircrafts mission capability is largely dependent on ECS.

Since ECS working principle is relatively complex, fault detection or fault identification can be very challenging. Most common failures are relatively easy to identify and trace to a specific component. Challenges however arise from complex interactions inside ECS, where single valve or sensor can affect to a whole system and cause undesirable and unknown phenomena. To better understand these complex interactions, comprehensive calculations or simulations are needed. When considering the complexity of ECS, computer modeling turns out to more suitable option than conducting multiple complex calculations.

Objective of this project was to improve fault identification process with semi-empirical model of the specific military fighter jet. Moreover, aim was to acquire more profound knowledge of the system and its characteristics. Modeling provided new way of studying ECS system, it flaws and potential failures. Model was created to answer questions that could not be tested on a test bench or on ground-tests. Basically, modeling enabled possibility to virtually test multiple different scenarios and their probability. Project resulted partially verified AMESim model of the ECS, which can be considered valid in most of the common flight situations. ECS-model helped to narrow down possible causes of undesirable behaviour that was known to occur in specific flight situation. ECS-model basically clarified the underlying phenomena leading to these undesired events.

In future, model’s reliability and accuracy will be enhanced with new comprehensive measurements. Model will also be transformed to simplified version which can be used to train new maintenance engineers.