Who is responsible for starting the engine in normal circumstances?

In typical flight operations, the responsibility for starting the engine generally falls to the flight commander pilot. This pilot holds a leadership position during flight and is primarily responsible for the overall safety and operation of the aircraft. Their authority extends to the critical phase of engine startup, as they possess the training and experience needed to assess the situation effectively and make quick decisions if any issues arise during the startup process.

While the rear cockpit pilot or either pilot could potentially initiate the engine startup in some scenarios, the flight commander's role encompasses ensuring that all protocols and procedures are followed properly, thereby centralizing this responsibility. The maintenance crew, while essential in preparing the aircraft and addressing any mechanical issues, is not responsible during the flight phase, especially during engine startup processes once the aircraft is in use.