If a required instrument on a multiengine airplane is inoperative, which document dictates if the flight may continue?

The correct answer involves the Master Minimum Equipment List (MMEL), which is a critical document that provides operational expectations regarding the functionality of instruments and equipment on an aircraft. When a required instrument on a multiengine airplane is inoperative, the MMEL specifies the conditions under which the flight can legally continue.

The Master Minimum Equipment List outlines the minimum equipment that must be operational for the aircraft to be considered airworthy. It also provides specific guidelines for how to handle inoperative instruments, including whether the flight can continue and under what conditions, thereby directly addressing the situation posed in the question.

This document is essential in operational decision-making, particularly regarding safety and compliance with aviation regulations. A pilot or dispatcher must reference the MMEL to determine the implications of the inoperative instrument on the flight's legality and safety. This is crucial for maintaining the safety of passengers and crew, ensuring adherence to aviation standards, and avoiding regulatory violations.

While the certificate holder's manual, original dispatch release, and pilot's briefing notes all contain relevant information about the operation of the flight, they do not specifically dictate the requirements and limitations concerning inoperative instruments in the same authoritative manner as the MMEL. The MMEL is the definitive reference in such scenarios, making it