The ICAO Secretariat is under the direct authority of the Secretary General. It consists of five bureaus: the Air Navigation Bureau (ANB), the Air Transport Bureau (ATB), the Technical Cooperation Bureau (TCB), the Legal Affairs and External Relations Bureau, and the Bureau of Administration and Services. IFATCA has interactions mainly with the ANB.

These five bureaus report directly to the Secretary General and each of them is supported by one or more Deputy Director. Depending on the bureau, there are also Chiefs for the different sections and a number of senior officers and technical officers.

The seven Regional Offices are also under the perview of the Secretary General and are supported by a Regional Director. To learn more about the Regional Offices, click here. The following chart describes the hierarchy in ICAO and the role of the Secretariat within the Organization:

ICAO

 

The Air Navigation Bureau is itself divided into three different groups: monitoring and oversight, air navigation capacity and efficiency, and aviation safety. IFATCA interacts mainly with the air navigation capacity and efficiency part of the ANB, and more specifically with the Airspace Management and Optimization Section (AMO). The work of the ANB touches four different elements:

Policy and Standardization

Safety and Infrastructure Monitoring

Safety and Infrastructure Analysis

Safety and Infrastructure Implementation

 
The ANB is also the focal point for the development and amendment of the GANP and the GASP: these two global plans are affecting all sections of the Bureau, but also all the Regional Offices. This is why the ANB also coordinates with the different PIRGs and RASGs, as well as with States and industry stakeholders when required in the various regions.
The bureau is also in charge of ICAO's response to the different crisis affecting aviation and is the lead for its contingency plans development. The following chart describes the hierarchy within the ANB and it's different sections:
 
ANB2