Ask an expert: what happens to my bags once I’ve checked them in?

Words: Emma Blackmore

You’re at the check-in desk. Your suitcase jolts forward and purrs along the conveyor belt until it disappears from view behind the rubber flaps. Then what?

“During the height of summer, we handle more than 54,000 bags at Heathrow T5 and 9,000 from T3 every day,” explains Laurie Keita, British Airways’ Head of Baggage and Logistics. 

That’s a lot of baggage. So, where does it all go? What happens next? How does British Airways work with Heathrow Airport to help customers get reunited with their bags at their destination? Here, Keita takes us behind the scenes for a bag’s-eye view of the journey…

1. The check-in desk

Three important things happen to your bag before you wave it goodbye: first, the weight and size are checked, then a bag tag is secured and finally your bag is whisked away.

“The tear-resistant bag tag (made of silicon and plastic) identifies the customer, their booking reference number, flight details (number, destination, date) plus a ten-digit bag tag number and a barcode,” explains Keita, who has worked with BA for 14 years. “The baggage handling system has hundreds of scanning points – the first one is just as your bag leaves the check-in desk. That scan checks the bag conforms to our size regulations.

And the reason for the weight limit? “Weight balance. We use an average bag weight to calculate the balance for the aircraft and fuel loads,” Keita says. “We don’t accept anything over 32kg as it’s not safe for our colleagues to handle.”

Fast-track fact: Should you keep your baggage stickers from other flights attached to your bag? “We always encourage customers to remove them,” says Keita. Additional barcodes may confuse the system, causing delays.

2. Sorting and screening

Now on its way, your bag is taken along conveyor belts to be sorted and screened. (There are 16 miles of conveyor belt at T5.) As you head through security, so does your bag. An X-ray machine screens every item. The specialist machine’s gantry rotates at a constant speed, taking hundreds of pictures to create 3D images in real time. This allows for more accurate judgements on the bag contents.

If something is flagged on the machine, a bag will be inspected to see what’s in it. If it contains a restricted item, such as a car battery, it will be removed and note placed in the bag. That item will be available to pick up from Heathrow Lost Property for a fee.

Fast-track fact: The baggage handling system at Heathrow T5 is six floors below Departures. In T3, it’s in a building adjacent to the airport.

3. Safe and sorted

Security complete, if the bag is early for its flight it’ll be transferred to an automatic bag store that can hold up to 6,500 bags in individual trays. Then, once it’s game time, the bag will enter the computer-controlled sorter (two huge oval-shaped loops) and then – you guessed it – be sorted into varnished wooden trays, one bag at a time.

“From there, the system will deliver the bag to what’s known as the build lateral,” says Keita. “This is a bank where bags are scanned once again and loaded by baggage handlers. The sorter is positioned directly above them and the bags are then gently tipped off their trays, down a chute and on to the correct lateral for each flight. The handlers then take over and scan the bags into unit loading devices (ULDs).” ULDs are containers precisely shaped to fit the aircraft hold, leaving minimal space around them. They allow for efficient pre-loading and planning of aircraft weight and balance. Each ULD has its own packing list so that its contents can be tracked. 

How is the loading order decided? The bags of connecting, frequent flyer and customers travelling in premium cabins will be packed last to make sure these bags are taken off the aircraft first at the other end. 

“The heaviest bags are packed at the bottom, while lighter items, such as car seats, are stored at the top,” Keita shares. “The team is very experienced at what shapes fit best where. Once loaded, containers are driven to the aircraft.”

Fast-track fact: In T3, BA uses robot arms and a piece of equipment known as an RTT (imagine a conveyer belt you can move in different directions) to load bags into the ULDs.

4. Into the hold

“Once the bags are tightly packed within the ULDs, they are locked into place with ‘stops’, which prevent movement,” Keita continues. Mail, fruit, vegetables, cargo, pharmaceuticals and cars might also be loaded in, depending on the aircraft’s load sheet.

What about man’s best friend? “Pets are carried in the ‘foot’ of the hold, which is temperature-controlled and pressurised to keep them comfortable,” Keita explains.

Fast-track fact: As the baggage hold isn’t temperature-controlled, your clothes may feel cold when you unpack. Sealed airtight bags such as crisp packets can expand or even pop due to the difference in air pressure.

5. Unloading

Once the plane has landed, drivers with trailers arrive to unload the ULDs from the aircraft. While you disembark the plane, any bags destined for connecting flights are taken to be processed (and to go through new rounds of security screening) – while terminating bags are taken to the reclaim hall. In T5, there are 11 reclaim belts (two for domestic flights, nine for international), while items that are large or bulky are manually placed in a designated area.

Fast-track fact: Ever noticed handlers loading individual bags outside your plane window? All planes have a ‘Hold 5’ designated area for loading last-minute baggage and items such as buggies that need to be readily accessible upon arrival.

And that’s it. It’s at this stage you’re reunited with your bag. Now it’s time for your trip to begin.

Find out all you need to know about baggage on British Airways flights here.