Which aircraft type requires an electric start when the APU is not operational?

The correct answer is the 787, as this aircraft type utilizes an electric starter for its engines, particularly when the Auxiliary Power Unit (APU) is not operational. This is an important aspect of the 787's design, as it incorporates more electrical systems compared to previous generations of aircraft, allowing for greater efficiency and reduced reliance on pneumatic systems.

In situations where the APU is not functioning, the electric starter enables the engine to be ignited using electrical power instead of relying on bleed air from the APU or the engines themselves, which may not be available. This feature highlights the 787's advanced engineering and innovation, which contributes to its operational flexibility, especially in situations where traditional starting methods are not accessible.

In contrast, other aircraft types, such as the 747, A320, and 777, have different starting systems that may rely on pneumatic sources, particularly from the APU or from ground power units, which leads to a different response when the APU is not operational. Understanding these differences is crucial for proper aircraft handling and safety protocols in fleet service operations.