You’ve arrived at the airport, checked in your hold baggage and it has disappeared down the conveyor belt; you can now head for the café, indulge in some retail therapy or open your laptop and get on with your work. But as you order your flat white, your suitcase is setting off on a complex but tightly choreographed progression which will end in your reunion at the baggage reclaim belt.
Once your case has vanished from view, it enters the fully-automated handling system and passes through the baggage security screening machine, which is about twice the size of the hand luggage scanner, and a vital cog in the process of keeping everyone on board safe. Security officers calculate the density of scanned objects in their search for contraband and, although these machines can’t work out specifically what every item is, they will detect both metallic and non-metallic objects, and also most organic materials, including food items. The scanner will identify a suspicious package with a red light, whilst a white light indicates further inspection is needed. Your case, of course, sails through the green light and on its way.
Baggage is tagged, usually with a barcode, and sorted according to whether it’s early for the flight, on time or, in some circumstances, whether it’s just missed it. Early Baggage Storage (EBS) systems allow passenger bags to be checked in well before the flight; some also enable users to track the identity and location of any bag at all times. This largely removes the possibility of lost luggage and can also allow accurate removal from the process if necessary.
Although the sophistication of baggage handling systems varies considerably from airport to airport, they can detect and manage any blockages in the system, regulate the flow of bags according to demand, and even align and rotate bags if necessary to ensure smooth passage.
Once your luggage is ready to be loaded, it’s conveyed to assigned Make Up Points (MUPs) where the luggage is assembled before being taken to the aircraft. Transfer to the aircraft takes place either by manual loading, also known as bulk loading, or by container-based loading.
Bulk loading involves baggage being transferred by conveyor belt from a luggage cart to the aircraft hold and then manually stored. Holds have shelving and netting in place to secure the cargo, and it also needs to be distributed evenly to ensure the aircraft is safely balanced. Until relatively recently, manual loading was the only way to accomplish this part of the process. However, technological advances, such as robotic loaders and towing vehicles for baggage transportation, are paving the way for further automatic handling devices.
Container-based loading is mostly used for wide-bodied aircraft and involves luggage being packed into containers called Unit Load Devices (ULDs). These come in a variety of sizes and are locked into position in the hold to ensure restraint of the load and protection of the aircraft. They are frequently transferable between different types of aircraft, which speeds up turnaround at hub airports. Some are constructed for specific purposes, such as fire-resistance or temperature control; there is even a ULD for the safe transportation of livestock. They are manoeuvred onto the aircraft by a cargo loader fitted with automated rollers which move ULDs from its platform to the hold.
When you arrive at your destination, the whole process is reversed; your case is taken from the hold, conveyed to a baggage cart or cargo loader and towed to the airport building. If you have an onward journey, your case will be conveyed to your next aircraft as quickly as possible. If you’ve arrived at your destination, it will be unloaded onto the baggage reclaim belt, where your eagle eye can pick it out and you and your luggage can set off for your holiday or meeting.
