Operational Measures
Introduction
The term "operations" in the context of aviation can be used to describe a broad range of activities including: the flying of the airplane, the control and/or monitoring of the aircraft by the air traffic management system, and the conduct of various airport activities. Operations begin with planning activities even before the passengers and cargo are loaded, through the entire flight, until after the passengers have disembarked and the cargo has been unloaded.
“Operational Improvements” from the ICAO basket of measures reflects changes to air traffic management (ATM) system and improvements to infrastructure and operations aimed at achieving a sustainable and efficient aviation system.
Together with the accelerated adoption of new and innovative aircraft technologies, and the increased production and deployment of sustainable aviation fuels (SAF), operational improvements will be one of the key components in achieving the long-term aspirational goal (LTAG) of net-zero carbon emissions by 2050.
Despite being depicted as a small wedge, Air Traffic Management (ATM) and improved operations offer the highest potential for reducing CO2 and related emissions in the short to medium term. According to LTAG Report, there could be regional variances in implementation of operational measures; however, there are opportunities for operations to reduce CO2 emissions through improvements in the performance of flights across all phases, including innovative measures such as formation flying.
The operational opportunities to reduce emissions represent a double win-win solution. First, based on the premise that the most effective way to minimize aviation emissions is to minimize the amount of fuel used in servicing and operating each flight, environmental benefits that are achieved through reduced fuel consumption also result in reduced fuel costs. Second, operational measures do not necessarily require the introduction of new equipment or the deployment of expensive technologies. Instead, they are based on different ways of operating aircraft that are already in service.
**For a more comprehensive overview of operational measures —including strategies beyond air navigation—please visit the Operational Improvements to Reduce Fuel Burn and Noise and Improve Local Air Quality webpage, which consolidates key approaches to fuel efficiency, emissions reduction, noise mitigation, and local air quality improvement."**
ICAO Publications and developments
In 2001, the ICAO Assembly requested the Council to promote the use of operational measures as a means of limiting or reducing the impact of aircraft engine emissions.
Since then, ICAO has been delivering some of the key analyses and guidance documents to support the calculation of the benefits that may be realized from implementing the operational measures defined in the ICAO-GANP Aviation System Block Upgrades (ASBU) framework together with new innovative measures looking out to the coming decades.
Optimization of air traffic management and operational procedures is a key to avoid unnecessary greenhouse gas emissions from aviation. The Global Air Navigation Plan (GANP) and the Aviation System Block Upgrades (ASBUs) are major initiatives developed by ICAO to that end. ICAO develops and updates the necessary tools and guidance to assess the environmental benefits associated with air traffic management improvements
ICAO developed rules of thumb to assist States with estimating the potential environmental benefits from the implementation of new operational procedures. These rules of thumbs are provided in the Doc 9988 Guidance on the Development of States' Action Plan on CO2 Emissions Reduction Activities.
Doc 10031 "Guidance on Environmental Assessment of Proposed Air Traffic Management Operational Changes" aim to support decision making when analysing proposed air traffic management (ATM) operational changes and provides States, airport operators, air navigation service providers (ANSP) and other stakeholders with environmental assessment guidance.
The report on "Environmental Community Engagement for Performance-Based Navigation" highlights the importance of effective community engagement and provides good practices that should be considered when undertaking airspace modernization.
Recently ICAO developed a new manual on "Doc 10177 Operational Opportunities to Reduce Aircraft Noise". This manual identifies and reviews both standard and innovative operational opportunities and techniques for minimising noise in civil aviation operations.
In 2017, ICAO delivered the first ever-global Horizontal Flight Efficiency (HFE) analysis. Following this, in 2022, ICAO completed the first global Vertical Flight Efficiency (VFE) analysis with the work initially focusing on the climb and descent phases.
"Scoping Report on Environmental Metrics of Relevance to the Global Aviation System" enables aviation stakeholders to assess the benefits of any operational measures. This report provides an overview of common metrics used by States and operational stakeholders to assess the environmental performance of aviation.
The ICAO Report on Environmental Interdependencies in Various Operating Scenarios (2025) analyses eight operating scenarios, highlighting trade-offs between noise, emissions, and efficiency, and providing insights into operational choices and their environmental interdependencies.
Towards the future
Aircraft operations are being optimized today to improve environmental performance while maintaining safety. With the realization of a global, interoperable, ATM system, in combination with innovative advances, the eventual achievement of future goals for aviation environmental performance will become possible.