Dangerous goods are carried regularly and routinely by air all over the world. To ensure that they do not put an aircraft and its occupants at risk, there are international Standards that each State, under the provisions of the Chicago Convention, is required to introduce into national legislation. This system ensures governmental control over the carriage of dangerous goods by air and gives worldwide harmonization of safety standards.
Annex 18 deals with the Safe Transport of Dangerous Goods by Air and sets down board principles; one of the Standards, however, requires that dangerous goods be carried in accordance with the Technical Instructions for the Safe Transport of Dangerous Goods by Air (the "Technical Instructions"). States are required by Annex 18 to have inspection and enforcement procedures in place to ensure that dangerous goods are being carried in compliance with the requirements.
The Technical Instructions contain a comprehensive set of requirements; among other things, they provide for the classification of dangerous goods and list these goods. The list identifies those goods which: a) are forbidden under any circumstances; b) are forbidden on both passenger and cargo aircraft in normal circumstances but could be carried in exceptional circumstances subject to exemption by the States concerned; c) are forbidden on passenger aircraft but permitted on cargo aircraft in normal circumstances; and d) are permitted on both passenger and cargo aircraft in normal circumstances. The Technical Instructions require that all dangerous goods be packaged and, in general, restrict the quantity per package according to the degree of hazard and the type of aircraft (i.e. passenger or cargo) to be used. There is generally no restriction on the number of packages per aircraft. The Technical Instructions also give the packing methods to be used and the packagings permitted, together with the specifications for those packagings and the stringent testing regime that must be followed. There are also requirements for the markings and labels for packages and the documentation for consignments.
In the Technical Instructions, there is a requirement that every package of dangerous goods be inspected externally by the operator before carriage to ensure that it is in a fit state and appears to comply with all the relevant requirements. Packages are subject to loading restrictions, including segregation of those containing incompatible dangerous goods and securement to prevent movement in flight. The pilot-in-command of an aircraft must be informed of the dangerous goods on-board and their location since, in the event of an emergency (not necessarily involving dangerous goods), the pilot-in-command, if the situation permits, must inform the appropriate air traffic services unit of what is on the aircraft to assist the emergency services in their response. The provision in the Technical Instructions allows pilots-in-command to exercise discretion in regard to conveying information about dangerous goods since they must judge the risks involved in diverting their attention (or the co-pilot’s attention) from controlling the aircraft in emergency situations.
Operators are aware of what dangerous goods have been loaded on their aircraft; in the event of an aircraft accident, the Technical Instructions require that they must, as soon as possible, inform the State in which the accident occurred of what was on-board and where it was located. However, it is possible that, depending on the circumstances and place of an accident, this information may not be readily available. The Technical Instructions also require that operators report to the relevant authority accidents and incidents involving dangerous goods. States, in turn, are required to have procedures in place to investigate such occurrences.
The Technical Instructions contain training requirements that apply to everyone involved in consigning, handling and carrying dangerous goods, and cargo and passenger baggage. These include the need for refresher training at two-year intervals and the keeping of training records. There are specific responsibilities for shippers and operators. Shippers must ensure that staff preparing consignments of dangerous goods receive training or that another organization with trained staff is used. Operators must ensure that their own staff and those of their handling agents are trained. Training programmes for operators are subject to approval by the State of the Operator.