Which aircraft model requires the flight attendant to "crack" the door before it is opened by the CSR?

The Boeing 737 has specific door operation procedures that require the flight attendant to "crack" the door before it can be fully opened by the Customer Service Representative (CSR). This process involves slightly opening the door to allow air to equalize the pressure in the cabin, which makes it easier and safer to open the door fully. This procedure is part of safety measures to ensure both the safety of the passengers and the proper functioning of the door mechanisms, as well as to prevent any sudden changes in cabin pressure when the door is opened after landing.

In contrast, other aircraft models, such as the Airbus A320, McDonnell Douglas MD-80, and Bombardier CRJ900, have different operational procedures for their doors, which may not require this "cracking" action prior to opening. This distinction underlines the importance of specific training for flight attendants on various aircraft types to ensure compliance with safety protocols.