What is the maximum speed to activate the service doors in-flight?

The correct answer indicates that the service doors on the ERJ 170/175 cannot be activated in-flight, which means they should be operated only when the aircraft is on the ground, specifically at zero knots indicated airspeed (KIAS). This limitation is crucial for safety because activating the service doors while in the air could lead to hazardous situations, including cabin depressurization or loss of cabin integrity.

When considering options such as 50, 100, or 150 KIAS, these speeds would suggest that it might be safe to operate the doors at certain flight conditions, which contradicts the operational safety protocols established for the aircraft. The design and engineering of the ERJ 170/175 ensure that service doors are designed to operate only when the aircraft is stationary, further reinforcing the importance of the maximum speed being zero KIAS in this context.