What is the purpose of the SYNC soft key on the ENG synoptic?

The purpose of the SYNC soft key on the ENG synoptic is to synchronize to N1 or N2 settings. When activated, this feature allows the pilot to adjust the thrust output of the engines so that they operate in tandem, particularly useful during flight phases that require precise engine management such as climb and cruise. By synchronizing the engines, pilots can more efficiently manage fuel consumption and ensure smoother operations, which is critical for maintaining optimal performance and safety.

The other options do not accurately reflect the function of the SYNC soft key. Synchronizing engine temperatures does not encompass the specific adjustment of engine performance metrics determined by N1 or N2 settings. Similarly, adjusting cruise fuel flow and initiating engine shutdown refer to different operational controls and procedures within the aircraft's systems, which are not related to the synchronization function.