Who among the crew members should dismount the apparatus when backing?

The reasoning behind the choice that states all crew members, except the driver/tiller, should dismount the apparatus when backing is rooted in safety and effective communication. When backing an apparatus, visibility is often limited for the driver, increasing the risk of accidents. Therefore, having the crew members dismount allows them to provide spotter assistance, effectively guiding the driver and ensuring a safer maneuver.

Each crew member can help monitor the environment around the apparatus, alerting the driver to any hazards, obstacles, or pedestrians that may not be visible from the driver's seat. This teamwork enhances safety and ensures that the backing operation is conducted smoothly. The presence of more eyes on the surroundings also increases the situational awareness of the entire crew, which is crucial in emergency response settings where time and safety are paramount.

Dismounting only those who are not directly involved in driving, like the other crew members, efficiently balances the need for safety without compromising the ability to operate the apparatus. The driver remains focused on controlling the vehicle while being assisted by the crew's observations.