In the context of aviation, “stand by” typically refers to a situation where a flight is not currently scheduled to depart but may be on standby for passengers or cargo to be accommodated. Here are a few specific meanings:
Passenger Standby: This occurs when a passenger does not have a confirmed seat on a flight but is waiting for an opportunity to board. This can happen in situations where a flight is overbooked, and passengers who have flexible travel plans may wait for available seats. If a confirmed passenger does not show up, standby passengers may be allowed to board.
Aircraft Standby: This can refer to an aircraft that is on standby for a potential flight. For example, if a flight is delayed or canceled, an airline might have another aircraft on standby to accommodate passengers.
Operational Standby: Air traffic control or airline operations may place flights on standby in case they need to be rerouted or if they need to be held before landing due to various reasons, such as weather conditions or air traffic congestion.
In all these cases, being on “standby” means that there is a possibility of being accommodated, but it is not guaranteed.