In which position must the firefighter's key be for the elevator to recall?

For the elevator to recall using the firefighter's key, it must be in the off position. This specific setting triggers the automatic recall of the elevator to a designated floor, typically the ground floor or a floor defined for emergency access, ensuring the elevator can be safely accessed by emergency personnel.

When the key is in the off position, it disables the normal operation of the elevator controls and prevents unauthorized use. This function is critical during emergencies, as it helps maintain control over the elevator system and ensures that firefighters or emergency responders can safely use the elevator without interference or risk of malfunction.

In the context of elevator operations, the other positions do not serve the purpose of recalling the elevator effectively. The on position would allow for standard operation of the elevator, which is not ideal in emergency situations, while the test position is meant for maintenance checks and does not allow for normal recall functions. The emergency position serves specific functions during a crisis but does not facilitate recall in the same way that the off position does.