Which of the following is NOT a function of the DEEC?

The correct choice indicates that fuel efficiency tracking is not a function of the Digital Electronic Engine Control (DEEC). The DEEC primarily focuses on managing and controlling various operational aspects of the engine such as monitoring faults, regulating speed, and limiting engine temperature.

Fault monitoring involves the detection and diagnosis of potential issues within the engine system, ensuring that it operates reliably and efficiently. Speed sanction control relates to maintaining the desired engine operating conditions under various load and environmental conditions, which is critical for performance and safety. Engine temperature limiting ensures that the engine operates within safe thermal limits to prevent damage and maintain reliability.

In contrast, while efficient fuel consumption is an important factor in overall aircraft performance and can be influenced by various systems, it is not a direct function of the DEEC. Fuel efficiency typically involves broader operational strategies, including flight profile optimization, which may not be a responsibility of the DEEC itself.