A survey of severe weather risk management in Europe reveals flight efficiency and safety performance gains to be achieved by better alignment of risk management strategies by ANSPs, Aircraft Operators and the Network Manager.
Effective management of severe weather impact on the ATM system and flight operations is of great significance for improving the safety and cost-efficiency of aircraft operations and ATC service provision in Europe; in particular, in congested airspaces. Severe weather phenomena disrupt air traffic flows and generate significant delays. If not managed properly, hazards to aviation associated with severe weather can lead to an unsafe, high level of pilot workload or controller workload, and ultimately to losses of separation and aircraft accidents.
In 2012, on stakeholder request, a dedicated severe weather risk management survey was carried out. The survey scope covered the entire chain of severe weather impact and risk management starting with weather forecasting by meteorological offices, addressing pre-tactical management by FMPs and the Network Manager and concluding with the deployment of tactical measures by ATC and pilots.
The information collected and analysed in the course of the survey revealed a number of potential areas for improvement of the meteorological products used in severe weather impact assessment and enabled the identification of important issues which need to be addressed in order to improve the management of severe weather impact on flight operations and ATM in Europe, notably:
- With a few exceptions, operational staff, responsible for severe weather risk management at ATC units, use standard weather forecasts and reports, weather radar data and some other meteorological products. Use of dedicated tools and models for assessment of severe weather impact on ATC and flight operations is rather an exception. ATM decision support systems making use of enhanced weather forecast products and ATC impact assessment algorithms are not yet in operational use.
- Meteorological products (forecasts and current weather reports) conform to standards (ICAO Annex 3). However, there are very few enhanced products, providing improved accuracy of weather forecasts, appropriate to support efficient pre-tactical severe weather impact assessment and decision making.
- Optimisation of ATM system performance at network level as opposed to optimisation at ‘local” level (optimal operation of network components does not mean optimal operation of the network) would require review of the current set of performance indicators and implementation of incentives for ANSPs.
The Major Conclusions
Sufficiently managed Hazard Encounter Risk and Knock-on Flight Safety Risk
The in-flight Hazard Encounter Risk and Knock-on Flight Safety Risk are consistently managed in accordance with ICAO PANS-ATM and PANS-OPS provisions, aircraft operating procedures and other applicable national regulatory provisions. However, it can be argued within the context of this project that the risk of controllers’ excessive workload (associated with the Knock-on Flight Safety Risk) is not sufficiently managed.
Inconsistent pre-tactical and tactical strategies
The severe weather hazard encounter prevention strategies and measures are applied inconsistently at the pre-tactical and tactical levels. The European ANSPs have developed and deployed different capabilities. In the majority of cases, severe weather risk management is not applied at the pre-tactical level. Some ANSPs have developed the needed capability and competence but the lack of incentives, and of an established process to capitalise on the available capabilities, prevents the implementation of an enhanced and more effective severe weather risk management. This leads to sub-optimal ATM efficiency and increased air traffic controllers’ workload, in particular in the critical time period before the tactical ATC measures take effect.
Non-interoperable pre-tactical and tactical strategies
In the rare cases of application, the risk prevention and mitigation strategies are based on locally developed capabilities, definitions and processes that are specific (not following common definitions, criteria, format, etc) and do not support an efficient communication and collaboration at Network level.
Sub-optimal performance of the European ATM Network. With respect to severe weather risk management the operation of the European ATM Network is suboptimal when applying the following criteria: (1) missed opportunities and (2) use of the available best practices. A risk management approach with adaptive incremental decision making presents a major opportunity for reducing weather related delays. The reasons for the sub-optimal performance can be found in the following groups of impediments:
- Lack of technical capabilities - tools to enable improved functioning of the risk management chain;
- Insufficient competence (e.g. lack of appropriate training) of involved actors;
- Lack of procedures - with few exceptions, operational supervisors are required to exercise their best judgement regarding the need to manage the anticipated impact of severe weather on the ATC operations;
- Lack of or inefficient incentives due to institutional and organisational reasons, such as: insufficient incentives for the ANSPs to introduce risk-based severe weather impact management and strategies that are optimised for the efficient operation of the Network; insufficient incentives for the meteorological service providers to go beyond the provisions of ICAO Annex 3 and provide information better supporting risk-based impact assessment and decision making; insufficient incentives for the FMPs to apply strategies at the pre-tactical level.
- Green Paper on the gains for the European ATM Network of aligned weather impact management, EUROCONTROL, September 2013
- Severe weather risk management survey, EUROCONTROL, April 2013
- SMART Wx Regulation Task Force WP1: Collaborative best practices for handling of adverse weather at European Aerodromes, EUROCONTROL, March 2021
- UK AIC: P 056/2010, "The Effect of Thunderstorms and Associated Turbulence on Aircraft Operations", 12 Aug 2010.
- Air Traffic Management Decision Support During Convective Weather, Mark E. Weber, James E. Evans, William R. Moser, and Oliver J. Newell, Lincoln Laboratory Journal, 2007
- CAP 493 - Manual of Air Traffic Services Part 1: UK CAA. Paragraph 17: "Weather Avoidance".