CAO (Cargo Aircraft Only) is the strictest operating restriction the IATA DGR places on air shipment of lithium batteries. Because a thermal runaway in a passenger cabin cannot be extinguished in flight, lithium batteries beyond personal-carry allowances (e.g., under UN3480 and PI 965) may be loaded only on all-cargo aircraft, whose holds are equipped with the required fire protection — they are banned from passenger aircraft belly holds. CAO booking requires the carrier to have dangerous-goods ground handling capability and to follow the IATA DGR lithium battery provisions throughout. HUIN operates a dedicated lithium battery airfreight team with certified declarants, covering booking, labelling and declaration in one flow so CAO shipments are approved and released compliantly..

Air eligibility depends on battery type, capacity, SOC and packaging: ① lithium-ion / lithium-metal batteries meeting IATA DGR Packing Instructions 965–970 may ship under the corresponding PI and Section (I / II / IB); the 2026 edition of the DGR sets stricter requirements on state of charge (SOC) and packaging materials; ② large EV battery packs and single storage cabinets normally exceed airfreight per-piece weight and size limits, so they must move by sea or rail; ③ some airlines add restrictions by country, airport or product, and damaged, recalled or mercury-containing batteries are prohibited outright. HUIN can review your battery model, capacity and SOC first to confirm CAO eligibility, preventing a booking that later bounces on cargo-type grounds..

Core documents include: ① a UN38.3 test report (proving the battery passed transport safety testing); ② an air transport appraisal certificate issued by an accredited laboratory confirming the cargo complies with the IATA DGR (commonly called the "air appraisal certificate); ③ an MSDS (usually valid for one year); ④ a DGD (Dangerous Goods Declaration) completed in English by a certified declarant per the DGR; and ⑤ for some airlines, a packaging certificate or special loading statement. Documents must match the actual cargo, or security screening will reject the shipment. HUIN arranges UN38.3, appraisal certificates and DGD preparation, coordinating express laboratory issuance and booking on the same day.

Three reasons: CAO is limited to freighter aircraft, whose capacity is far smaller than passenger fleets, so base rates are high; lithium batteries are charged as Class 9 dangerous goods with a dangerous-goods handling fee that varies by airline; and appraisal documents, special packaging and security screening cost more than for general cargo. Pricing follows standard airfreight practice of charging the greater of volumetric or actual gross weight (volumetric weight = L × W × H cm ÷ 6000; some airlines use 5000), with a DG surcharge added for CAO. If lead time allows, compare sea freight (typically 1/5–1/10 of the air cost) or consolidate several shipments to spread the cost. HUIN gives an immediate all-in rate including the DG surcharge and can provide a sea-versus-air comparison for your decision..