RTE international and Airtelis pave the way for safe helicopter-assisted live-line work at Elia
Paris, September – Airtelis and RTE international have been selected by Elia, Belgium’s electricity transmission system operator, to define the safety framework required to carry out helicopter-assisted live-line work on its grid. The assignment, which began in 2024 under a multi-year contract, forms part of a collaboration between RTE international and Elia spanning nearly fifteen years.
Ensuring operator safety before any intervention
Ensuring operator safety lies at the heart of live-line work. This requirement is based on two complementary processes:
The Work Execution Conditions (CET, Conditions d’Exécution du Travail), a reference document that defines in advance the conditions under which each operation can be carried out safely;
The Special Operating Regime (RSE, Régime Spécial d’Exploitation), a study carried out before each operation to take account of the grid configuration at the time of the work and verify that these conditions are met.
Drawing up the CET brings together several complementary areas of expertise within RTE international: live-line work, overvoltage studies and power system modelling.
The overvoltage studies are based on the specific characteristics of Elia’s grid, including substations, overhead lines and underground cables, which are modelled using EMTP (ElectroMagnetic Transients Program) software. The model is then used to simulate various faults and failures in order to identify potential overvoltage levels and, based on these results and the applicable international standards, determine the safety clearances to be observed.
The high density and meshed structure of the Belgian grid, together with the age of some of its infrastructure, required rigorous data collection and modelling to produce an accurate representation of the grid and provide the most appropriate recommendations.
Safety and helicopter-assisted work: two areas of long-standing expertise
To meet Elia’s safety requirements, RTE international provides the Belgian TSO with a distinctive strength: a strong safety culture built on the live-line working methods developed by RTE, which are now recognised as benchmarks within the industry. This expertise is complemented by that of RTE’s Helicopter Works Department (STH, Service Travaux Héliportés), which draws on 70 years of experience in helicopter-assisted work on electricity networks, expertise that is unique worldwide.
This combination of rigorous safety methodology and RTE’s operational expertise ensures that Elia benefits from high standards in an area where there can be no compromise when it comes to operator safety.
