What is the specified number of training hours required to add a multiengine rating to an existing pilot certificate?

The regulations governing the addition of a multiengine rating to an existing pilot certificate do not specify a required number of training hours. Instead, the FAA mandates that pilots must demonstrate proficiency and complete the necessary training, but it allows for flexibility in how much time is needed. This means that the individual pilot's experience, skills, and the specific requirements of the training program can dictate the amount of time it takes to achieve the necessary competencies. Consequently, the final decision regarding training duration rests with the instructor based on the pilot's readiness, rather than a set number of required hours. This approach enables tailored instruction that accommodates the varied learning paces of different pilots.