How luggage works in airport

Pack your cabin bag with medication, a single change of clothes, travel documents and chargers; check remaining suitcases while keeping each checked item to ≤23 kg (50 lb) and a linear size (length + width + height) of ≤158 cm (62 in) to avoid most overweight and oversize surcharges.

Carry-on maximum commonly accepted by major carriers is 22 × 14 × 9 in (≈56 × 36 × 23 cm) including wheels and handles. Use a household scale at home and a dimension tape for cases – a 0.5–1 kg margin avoids rebagging at the counter.

At check-in you’ll receive a printed barcode tag showing a three-letter destination code; retain the tear-off receipt. Modern sorting systems read tags automatically and route pieces via conveyor sorters and tilt-tray or cross-belt modules. Electronic bag tags and RFID are increasingly deployed; a battery-powered Bluetooth tracker placed in the cabin item provides faster location updates but keep spares and large cells in the cabin only.

Security screening rules for carry items: the 3-1-1 limit applies – containers ≤100 ml (3.4 oz) inside a single 1 quart / ~1 L clear bag. Remove laptops or tablets from cases if requested; large photographic equipment is safest in the cabin. Spare lithium batteries must remain in carry-on: ≤100 Wh allowed, 100–160 Wh permitted with airline approval, >160 Wh generally prohibited as spares.

Typical fee ranges on many US routes: first checked piece $25–$35; overweight charge for >50 lb (23 kg) commonly $100–$200; for >70 lb (32 kg) expect $200–$400. Oversize surcharges apply when linear dimensions exceed 158 cm (62 in).

If a piece is delayed or damaged, file a Property Irregularity Report at the carrier desk immediately and keep your boarding pass plus tag receipt. Photograph the external tag, internal contents and any damage. For fragile or high-value goods, carry them in cabin, use a hard-shell case with internal padding, and secure with an TSA-compatible lock to permit inspection without forced entry.

Checking a bag at kiosks or counters: weight limits, tags and fees

Weigh and measure your checked suitcase at home and target 20–22 kg (44–48 lb) for a 23 kg (50 lb) allowance or 28–30 kg (62–66 lb) for a 32 kg (70 lb) allowance to avoid overweight charges.

At the kiosk (self-service)

• Steps: scan your booking or passport, select number of pieces, print the tag, attach tag to handle, then proceed to the bag drop or staffed counter if instructed.
• Tag attachment: thread the tag loop through the main carry handle and secure the locking piece; place the barcode face-up for scanning.
• Weighing: some kiosks have an integrated scale – if the kiosk shows over limit, you will be prompted to pay or reconfigure pieces before printing.
• Retain the claim stub printed with the tag barcode and check-in reference; it’s required to collect compensation for mishandled items.
• Payments: kiosk accepts card payments for excess-piece, overweight and oversized fees; keep the payment receipt with the tag stub.

At the staffed counter

• Agent reweigh: counters frequently reweigh every piece. If the bag exceeds allowance, expect an overweight charge or requirement to repack into carry-on items.
• Tag verification: staff will attach the final tag with routing code (three-letter destination) and scan it into the system; verify the destination printed on the tag before surrendering the case.
• Special items: declare sports equipment, musical instruments, and items requiring special handling; oversized instruments may require a paid seat or cargo handling.

Fees and common thresholds

• Typical piece limits: economy fares on many carriers = 1–2 pieces free on some international itineraries, otherwise first piece often charged on domestic short-haul routes.
• Weight caps: standard checked-piece limits are 23 kg (50 lb) and 32 kg (70 lb). Items over 32 kg usually must travel as cargo or incur very high surcharges.
• Common fee ranges (approximate and variable by carrier and route): first checked piece $0–$35, second checked piece $35–$60 on short-haul fares; overweight 23–32 kg $75–$200; overweight >32 kg frequently $200+ or refused at check-in; oversize (linear dimensions >158 cm / 62 in) $100–$300.
• Waivers: elite status, premium fares and many co-branded credit cards can waive first- or additional-piece fees–confirm specific eligibility on the carrier’s policy page.

Practical tips

1. Weigh and measure at home with a luggage scale; adjust to be 1–2 kg under the published limit.
2. Move dense items to carry-on if you risk hitting the weight threshold (battery banks, cameras – note spare lithium batteries must travel in the cabin only).
3. Label inside and outside with name, phone and itinerary; tuck a checklist of valuables in your personal item rather than checked piece.
4. If kiosk prints a provisional tag, confirm final tag and routing at the staffed counter before walking away.
5. Keep digital photos of your bag and contents for claims purposes and keep the claim stub until baggage is returned.

What happens to your carry-on during security X‑ray and liquid screening

Place all liquids, gels and aerosols in a single clear, resealable bag with containers no larger than 100 ml / 3.4 fl oz, one bag per passenger; remove that bag from your carry-on and put it in a screening tray unless signage or a CT checkpoint explicitly allows it to stay.

At the X‑ray belt a tunnel scanner produces a two‑dimensional image that separates organic, inorganic and metal densities by color/contrast; advanced CT scanners create 3D slices and give officers a clearer view without items overlapping. If the image shows an ambiguous shape, trays are pulled for manual inspection or the bag is opened for closer examination.

Remove large electronics (laptop, DSLR body with lens attached) and place them in their own tray for standard 2D lanes; many modern CT lanes permit these items to remain inside the cabin bag, but signage varies by checkpoint–follow the lane instructions. Keep phones, small tablets and e‑readers accessible: officers may ask you to power devices on to verify functionality.

Items that appear suspicious or are obscured by dense packing will trigger secondary screening: officers will open the bag, spread contents on a table, perform visual inspection and may swab surfaces for trace explosives (explosive trace detection, ETD). Expect brief questioning and potential temporary seizure of prohibited items; criminal items or threats are referred to law enforcement.

Medications, baby formula and breast milk exceeding 100 ml are allowed but must be declared and presented separately for inspection; carry prescriptions or a clinician’s note when feasible to reduce delays. Unlabeled or improvised containers are more likely to be removed for testing and may be discarded.

Common causes of additional checks: liquids over the limit, dense or wrapped electronics, containers made of metal or foil, concealed batteries or power banks, and tightly packed bags that hide shape details. Pack to minimize overlap: place the clear liquids bag and large electronics near the top, empty pockets of coins and keys, and avoid metal cases or dense insulating sleeves.

Consequences for prohibited items include immediate confiscation, possible fines, and in extreme cases detention. Allow extra time at security when carrying multiple devices, medical liquids or camera equipment; obey signage and officer instructions to speed the screening process.

Checked-bag screening: X‑ray, explosive-trace detection and manual-inspection triggers

Place powders, spare batteries and electronics in an accessible pocket or clear bag and remove loose cells: this simple step lowers the chance your checked item will be opened for further checks.

X‑ray and computed tomography (CT) screening – technical summary

Most hold baggage passes through multi-view X‑ray or CT machines that use dual-energy imaging and 3D reconstruction; modern checked-bag CT scanners operate at tube voltages roughly 120–160 kVp and produce volumetric images that automated explosive‑detection systems (EDS) score against signature libraries. EDS flags shapes and material densities that match known explosive signatures; when the algorithm score exceeds a site threshold, the bag is diverted. Throughput rates vary by model, but a high-capacity CT line can process hundreds of bags per hour per lane.

Explosive trace detection (ETD) and manual inspection triggers

ETD uses swab sampling plus ion mobility spectrometry (IMS) or mass‑spec devices; sensitivity typically reaches low‑nanogram levels for common explosive residues. Common causes for ETD/manual intervention: EDS alarm, positive ETD swab, visible powders or liquids, complex electronics with dense shielding, unshielded wiring or batteries, undeclared hazardous items (firearms, compressed gas, aerosol cans), route/tag anomalies, or intelligence-based selection. Typical flag rates reported by several ground-handling operations fall roughly in the 1–5% range, but rates vary by terminal and screening policy.

When a bag is opened technicians use gloves, forceps and portable test kits; canine teams or secondary chemical analysis may be used. After inspection, handlers reseal with tamper-evident tape, insert a written receipt stating why the bag was opened, and return it to the dispatch stream. If prohibited items are found they are either removed and documented or retained per local law enforcement rules.

Packing recommendations that reduce false positives: keep powders (protein mixes, spices) in clear resealable bags; stow toiletries in the same compartment; avoid wrapping items in multiple layers of foil or dense padding that masks shapes; secure loose wiring and small batteries in a single container; send spare lithium batteries only in carry items (spare cells are commonly banned in checked compartments). If transporting collapsible baby gear, collapse and secure it – for a compact option see best inexpensive double umbrella stroller. Do not pack fuel or liquid fuel containers; for cordless power tools or mowers verify battery rules before shipping and consult product guidance such as best cordless lawn mower with mulcher if unsure.

If your bag is selected for additional screening, expect a 10–30 minute delay on average for a routine open-and-repack inspection; prolonged holds occur when law enforcement is required. Clear labeling, simple internal packing and following battery/flammable-item rules reduce the odds of secondary screening and speed return if an inspection occurs.

Baggage handling: sort, route and load onto aircraft

Attach a durable machine-readable tag on the main handle with the barcode facing outward and, if available, request RFID encoding – first-scan read rates climb to ~99% with RFID and misroute incidents fall by roughly 40–60% compared with barcode-only handling.

Sorting technologies and throughput

Incoming bags are scanned at an intake tunnel (barcode OCR + RFID antenna array). Read success at first pass: barcode tunnels 95–99% (depends on tag placement, dirt, folds); RFID tunnels 98.5–99.9% (tag density and antenna layout matter). After identification, control software assigns a destination gate or make-up queue and actuates one of several sorter families:

– Tilt-tray sorters: throughput typically 3,000–7,000 bags/hour; large footprint; high routing flexibility; suited for hubs with many destinations.
– Cross-belt sorters: throughput typically 2,000–5,000 bags/hour; moderate footprint; fast single-pass ejection, good for medium-density flows.
– Pusher/diverter systems: throughput typically 500–2,500 bags/hour; low footprint; used for short-distance diversion (e.g., security-referred items or small transfer clusters).

Routing logic, make-up and aircraft loading

Routing software combines flight manifests, transfer windows and ULD availability to create dynamic routes and make-up plans. Bags destined for the same flight are directed to a make-up belt or a dedicated ULD build area where handlers stage and consolidate items by gated sequence. Typical operational timings observed at busy gates: make-up completed 30–60 minutes before pushback for narrowbodies and 45–90 minutes for widebodies; final transfer cutoff commonly 15–25 minutes before departure for connecting bags.

Container/pallet build rules enforce weight distribution and center-of-gravity constraints: handlers follow a printed or tablet load plan that prescribes left/right and forward/rear placement. Automated load sequencing can produce pick lists for belt loaders; manual overrides occur for overweight items or irregular shapes. Standard conveyor speeds inside sortation are 0.5–1.5 m/s; fast ejection on cross-belt sorters reduces dwell time and keeps flow balanced during peak surges.

To reduce misloads and delay: present tagged items cleanly, accept RFID-enabled tagging where provided, and observe published transfer cutoffs. On the ground side, ground handling teams map bag counts to ULD counts continuously and stage empty ULDs so that containerization completes well before the aircraft boarding phase begins.

Barcode and RFID tracking for delayed or lost bags; filing a claim

Report a missing bag at the airline’s baggage service desk immediately and insist on a Property Irregularity Report (PIR) number before leaving the terminal.

• Barcode vs RFID – brief operational facts:
  • Barcode tags require line-of-sight scans at check-in, transfer points, loading and arrival; each scan writes a timestamp and location into the carrier’s baggage system.
  • Passive UHF RFID (860–960 MHz) used by many carriers has read ranges up to ~8–10 m in ideal conditions; real-world read rates are typically 85–98% depending on tag placement and reader density.
  • Active tags are rare for checked items because of battery and carriage regulations; Bluetooth trackers (BLE) rely on device ecosystems and may be restricted by some carriers.
• Common RFID scan points: check-in islands, primary sorters, transfer conveyors, loading docks, and arrival carousels. Airlines and handling agents typically push scan events to centralized systems (for example, SITA WorldTracer) so a single PIR number links all scans.
• Primary failure modes: unreadable barcodes (wrinkled/wet tags), RFID tag orientation, dense packing, metal or liquid nearby, reader gaps. Photographs of your checked tag and the bag exterior increase recovery success if a tag becomes unreadable.

Practical tag and packing recommendations

• Photograph the barcode/ID stub, tag number and bag interior immediately after check-in; store images in cloud and on your phone.
• Attach an exterior tag sleeve OR a secondary paper tag inside an internal pocket; remove old airport tags before departing the arrival area.
• Use a visible contact card (name, mobile, email) inside and outside the bag; add a small, unique marker (colored ribbon) to speed visual identification on carousels.
• Consider protective wrapping – see best plastic wrap for options – and use a sturdy, tamper-evident tag holder for the barcode/RFID label.
• If you carry an electronic tracker (BLE, AirTag, Tile), verify the carrier’s policy for checked bags; placing the tracker in carry-on avoids battery restrictions and increases location visibility via passenger devices.

Step-by-step claim procedure and documentation

1. At the terminal:
   • File a PIR at the carrier’s baggage desk. Obtain the PIR number, name of the agent, and a written copy or screenshot.
   • Keep the boarding pass, tag stub, passport/ID and any transfer receipts; take notes of carousel number, flight numbers and time of arrival.
2. Within 24–48 hours:
   • Monitor carrier tracking (airline app or WorldTracer) using the PIR/reference number; report additional location info if you receive scans from RFID/barcode events.
   • If no desk was available at arrival, file the PIR online immediately and save the confirmation email.
3. Documentation to attach to any written claim:
   • PIR number and carrier reference.
   • Boarding pass and bag tag stub images.
   • Passport/ID and flight itinerary.
   • Photos of the bag, internal contents, and damaged items (if applicable).
   • Itemized list of contents with estimated values and original receipts where available.
   • Receipts for emergency purchases (toiletries, clothing) you want reimbursed; label each with date and purpose.
4. Legal and timing milestones:
   • For international travel under the Montreal Convention, airline liability for checked items is limited to 1,288 SDRs (Special Drawing Rights); SDR-to-USD value fluctuates – check current conversion when filing.
   • Submit written complaints within the Convention windows: damaged baggage within 7 days of receipt; delayed baggage claims within 21 days beginning when the item was made available. If the bag has not been returned within 21 days it is commonly treated as lost and a final loss claim may be filed.
   • Statute of limitations for legal action under the Convention is two years from the date of arrival or from the date the baggage should have arrived.
5. Follow-up and escalation:
   • Keep a running log of all contacts, emails and reference numbers. If tracking shows repeated scans but no delivery, request the receiving station’s location and ask for a targeted search of the last-read sort bay.
   • If the carrier’s response is unsatisfactory, escalate to the airline’s customer relations department, your travel insurer, or the national aviation consumer protection authority (for US flights, the DOT).
   • Use credit-card purchase receipts and travel insurance policy details to supplement a claim; some cards provide higher reimbursement limits or faster interim compensation for essentials.

Suggested claim message structure: short factual header with PIR and flight numbers, bullet list of missing/damaged items with values and receipts attached, statement of requested remedy (repair, replacement or monetary compensation) and bank/payment details for settlement.