Cargo Aircraft Only (CAO)
Cargo Aircraft Only (CAO) is a designation, under the IATA Dangerous Goods Regulations, for dangerous goods that may be carried only on freighter (cargo) aircraft and not on passenger aircraft. Certain hazardous materials are permitted in larger quantities, or at all, only when there are no passengers aboard, and such consignments must bear the “Cargo Aircraft Only” label and be documented and loaded accordingly.
The distinction exists because the acceptable risk and quantity limits differ sharply between a passenger flight and a freighter. Air-cargo acceptance staff must recognise CAO items and ensure they are not loaded on passenger services, and forwarders must route them on freighters. CAO is an important part of dangerous-goods handling in air freight, working alongside the packing group, quantity limits and proper shipping name that govern whether and how a hazardous item can fly.
Some dangerous goods are simply too hazardous, or too large in quantity, to fly with passengers — the CAO designation keeps them on freighters only. Recognising CAO items and routing them correctly is a critical air-cargo safety check; getting it wrong puts prohibited hazards on a passenger aircraft. It is core dangerous-goods knowledge in air freight.
What does Cargo Aircraft Only mean?
The dangerous goods may only be carried on freighter aircraft, not on passenger flights, and must bear the CAO label.
Why are some goods CAO?
Their hazard or permitted quantity is acceptable only where there are no passengers aboard.