Which of the following doors is not displayed on the DOORS synoptic page?

The flight deck escape hatch is not displayed on the DOORS synoptic page because this page is primarily focused on the main operational doors that impact the aircraft during standard operations, such as boarding, cargo loading, and emergency situations.

The service door, forward cargo door, and emergency exit door are all critical for normal operations and emergency evacuations, which is why they are included in the synoptic display. The flight deck escape hatch, while important for the flight crew's safety, is not commonly referenced in operational scenarios covered by the DOORS synoptic page, as it is primarily an escape route for the crew rather than a door involved in day-to-day aircraft operations. This distinction highlights the specific focus of the synoptic page on doors that serve more generalized aircraft use.