Air cargo is screened to stop explosives, incendiary devices and other threats from being loaded onto aircraft. The international baseline is set by ICAO Annex 17; each state then implements it through its own aviation security programme. The short answer to “who is responsible?” is: the aircraft operator remains accountable for the security of what it loads, but most countries allow screening and security controls to be applied earlier in the supply chain by approved, audited companies — and the cargo must then be protected from tampering until it reaches the aircraft.
The international framework (ICAO Annex 17)
Annex 17 to the Chicago Convention requires states to ensure that cargo and mail carried on commercial flights are subjected to appropriate security controls, including screening where practicable, before loading, and that they are protected from unauthorised interference from the point at which security controls are applied until departure. It also requires a supply chain security process with regulated agents and/or known consignors where states use them. The details — which methods are allowed for which commodities — are set nationally.
United States: TSA rules
- 100% screening on passenger aircraft. Section 1602 of the Implementing Recommendations of the 9/11 Commission Act of 2007 requires all cargo transported on passenger aircraft to be screened at a level of security commensurate with checked baggage. TSA reported reaching 100% for cargo on domestic passenger flights in 2010 and for international inbound passenger flights at the end of 2012.
- Aircraft operators (49 CFR Part 1544) and foreign air carriers (Part 1546) must carry out the screening required by their TSA-approved security programmes.
- Indirect air carriers (freight forwarders, 49 CFR Part 1548) accept cargo under their own security programme.
- Certified Cargo Screening Program (CCSP) (49 CFR Part 1549). Shippers, forwarders and third-party facilities can be certified by TSA as Certified Cargo Screening Facilities. They screen cargo with TSA-approved methods, apply strict chain-of-custody measures and tender already-screened cargo to the airline.
- Approved equipment. TSA publishes the Air Cargo Screening Technology List (ACSTL), which lists the X-ray, explosives detection and trace detection equipment that regulated parties may use for cargo screening.
European Union: secure supply chain
- The framework is Regulation (EC) No 300/2008, with detailed measures in Commission Implementing Regulation (EU) 2015/1998, Chapter 6 (cargo and mail). Parts of the detail are not public.
- Regulated agents (typically forwarders and handlers) are approved by the national authority and may screen cargo or accept it as secure.
- Known consignors are shippers whose own premises and processes are approved, so their goods can enter the secure supply chain without being screened later — provided they stay protected.
- Cargo that is not from a known consignor and has not been screened by a regulated agent must be screened before loading. In effect, everything loaded must be either screened or originate from a secure supply chain.
- ACC3 (Air Cargo or Mail Carrier operating into the Union from a Third Country Airport) designation applies to carriers flying cargo into the EU from non-EU airports, with independent EU aviation security validation of their operations and supply chain.
- Advance cargo information (ICS2 pre-loading data) allows authorities to request additional screening before a consignment is loaded at the origin airport.
Screening methods
| Method | Good for | Limitations |
|---|---|---|
| X-ray (single-view, multi-view, dual-energy) | Most general cargo at piece level; fast | Dense or cluttered items, large consolidated pallets, metal-heavy goods |
| Explosives detection systems (EDS / CT) | Automated explosives detection at higher assurance | Tunnel size, throughput, cost |
| Explosives trace detection (ETD) | Items that cannot be imaged well; alarm resolution | Depends on sampling access; see ETD |
| Explosive detection dogs | Larger volumes, mixed consignments | Handler and dog availability, fatigue, approval rules |
| Physical / hand search, visual check | Small volumes, unusual items | Slow, intrusive |
| Metal detection equipment | Certain homogeneous commodities | Only finds metal |
| Simulation chamber | Detecting barometric-triggered devices | Niche |
Equipment for air cargo ranges from parcel tunnels similar to checkpoint baggage scanners to large-aperture pallet and ULD systems. Breaking down consolidated shipments to piece level before screening usually gives much better images than scanning a built-up pallet.
Perishables, dense items and other difficult cargo
Some commodities are hard to screen with the default method. Perishables (fresh fish, flowers, fruit, pharmaceuticals) are time-critical and often shrink-wrapped or temperature-controlled, so screening has to be fast and non-destructive — typically X-ray at piece level, ETD, dogs or physical check. A holding or “cooling-off” period, which some national programmes allow as a control for certain consignments, is unsuitable for perishables because of the delay. Dense items such as lead-acid car batteries, engines, metal castings or stone can block X-rays so that the contents cannot be cleared from the image; these are usually resolved by visual inspection, ETD or physical search. Batteries are also dangerous goods with their own packing and acceptance rules under the ICAO Technical Instructions / IATA Dangerous Goods Regulations, which is a separate process from security screening.
Reading air cargo X-ray images
Analysts look for the same things as in baggage screening — wires, power sources, organic masses, detonator-like objects — but in a much wider variety of packaging. Dual-energy colouring helps separate organic from inorganic material (see X-ray image colours), and many programmes include image-interpretation training and testing, sometimes with Threat Image Projection.
Frequently asked questions
Who bears responsibility for X-ray screening of air cargo?
The aircraft operator is ultimately responsible for the security of the cargo it loads, but national programmes let approved parties — TSA-certified cargo screening facilities and indirect air carriers in the US, regulated agents and known consignors in the EU — screen or secure cargo earlier in the supply chain.
Is all air cargo X-rayed?
Not necessarily X-rayed, but in the US all cargo on passenger aircraft must be screened, and in the EU all cargo must be screened or come from a secure supply chain. X-ray is the most common method; ETD, dogs and physical search are also approved.
Which is not a security control for perishable cargo?
X-ray, ETD and physical checks can all be used for perishables. A cooling-off (holding) period is generally not used for perishables because the delay would spoil the goods.
Can car batteries be screened by X-ray for air cargo?
They can be X-rayed, but lead plates and acid make them very dense, so the image often cannot clear them. Alternative methods such as visual inspection or physical search are used, and batteries are also subject to dangerous goods rules.
Sources
- TSA — Cargo programs and the Certified Cargo Screening Program
- Federal Register — Air Cargo Screening interim final rule (2009)
- eCFR — 49 CFR Part 1549, Certified Cargo Screening Program
- EUR-Lex — Commission Implementing Regulation (EU) 2015/1998
- European Commission — Air cargo and mail security (ACC3)
- ICAO — Aviation security (Annex 17)
Last reviewed on 2026-10-04.