Across Europe, reducing Auxiliary Power Unit (APU) use has moved from environmental ambition to an operational issue for airports. Fixed Electrical Ground Power (FEGP), Ground Power Units (GPU) and Pre-Conditioned Air (PCA) are beign deployed to reduce reliance on APUs during turnarounds, while local rules define when and for how long an APU may operate.But there is an important distinction between having an APU restriction and being able to demonstrate how it is applied in daily operations.Under the Alternative Fuels Infrastructure Regulation (AFIR, Regulation (EU) 2023/1804), Europeans airports on the TEN-T core and comprehensive networks must provide electricity supply to stationary aircraft at all gates from January 2025 and at all remote stands from January 2030.However, there is no single European maximum APU runtime. Actual restrictions remain mostly governed by airports and local authorities.For airports operators, the challenge is therefore moving from rules to evidence: understanding what actually happens aircraft by aircraft, stand by stand and turnaround by turnaround as Nice Côte d’Azur airport use case.
APU restrictions in Europe: a largely local framework
APU restrictions differ significantly between European airports.
Amsterdam Schiphol
APUs may normally operate for a maximum of five minutes after arrival and five or ten minutes before departure depending on aircraft type. Exceptions can apply under defined operational conditions.
London Heathrow
FEGP and PCA are considered primary energy sources, while the APU is treated mainly as a contingency solution. For most aircraft, APUs must be shut down within ten minutes of arrival, while departure allowances vary depending on aircraft category and operational conditions.
Marseille Provence, France
In France, local decrees establish APU restrictions for major airports. At Marseille Provence Airport, when electricity and heating or cooling alternatives are available, APU use is limited to ten minutes before scheduled departure and ten minutes after arrival. The airport operator must also provide authorities with available information that helps assess actual APU runtime and the use of substitution equipment.
Why APU restrictions are becoming a strategic operational
The first stage of an APU reduction strategy is straightforward: define restrictions and provide alternative ground infrastructure. The second stage is more difficult. An airport needs to understand whether external power is actually available when required, whether crews and handlers use it, whether the APU is switched off accordingly and when this does not happen, why. A stand can theoretically offer FEGP or PCA while an aircraft continues operating its APU because of equipment failure, delayed connection, cabin-conditioning requirements, aircraft-specific procedures or coordination issues during turnaround. This changes the management question. It is no longer simply: “Are our stands equipped?” It becomes: “When the infrastructure was available, was it actually used and did it generate the expected operational behaviour?” Installed capacity and operational use are two different KPIs.
A shared issue between airports, airlines and handlers
APU reduction cannot be managed effectively by one stakeholder alone. For the airport operator, the challenge is to connect infrastructure availability with real aircraft behaviour. A low compliance rate may indicate insufficient infrastructure, poor equipment reliability or limited adoption. For airlines, reducing unnecessary APU runtime can support fuel-efficiency and environmental objectives, but operational and safety requirements remain decisive. Reliable data should therefore distinguish avoidable runtime from legitimate exceptions. For ground handlers, equipment connection timing and availability are critical. Delayed GPU, FEGP or PCA connection can directly extend APU runtime. This makes APU performance a shared turnaround KPI rather than simply an environmental indicator.
Why traditional compliance monitoring has limitations
An airport operating instruction defines what should happen. It does not automatically show what happened. Manual airside audits remain useful, but they only capture the operations observed during a specific period. Likewise, emissions inventories and modelling tools can estimate APU-related emissions but do not necessarily establish the exact behavior of individual aircraft during each turnaround. For operational performance management, airports increasingly need more granular evidence. Ideally, the turnaround timeline should make it possible to identify: Aircraft on-block → external power available → external power connected → APU switched off → APU restarted → off-block This sequence can then be contextualised using information such as:
From infrastructure to operational evidence
As ground-power infrastructure becomes more widespread across European airports, the strategic question will increasingly shift from availability to utilisation. This is where APU monitoring can evolve from an environmental reporting exercise into an operational management tool. At Nice Côte d'Azur Airport, Waltr's Aircraft Emission Tracker detects and measures APU and main-engine use at aircraft stands. The approach combines systematic observation with reporting and change-management support to help airport teams understand operational practices and measure progress.
For European airports, the next step is therefore not simply introducing stricter rules. It is building the operational evidence required to understand whether those rules are producing measurable change. Want to understand how APU use can be measured across your airport operations?
SourcesEuropean Commission – Alternative Fuels Infrastructure Regulation Q&A. Particularly Article 12 guidance on electricity supply to stationary aircraft and the Commission's clarification that AFIR does not prohibit APU operation.European Commission AFIR Q&ARegulation (EU) 2023/1804 – Alternative Fuels Infrastructure Regulation. Article 12 establishes electricity-supply requirements for stationary aircraft at TEN-T airports.Regulation EU 2023/1804 on EUR-LexICAO – Airport Air Quality Manual, Doc 9889. Guidance on APU restriction, alternative ground supplies and the need to consider operational and safety interdependencies.ICAO Airport Air Quality ManualAmsterdam Airport Schiphol – Minimising APU usage. Current APU limits, exemptions, monitoring and enforcement framework.Schiphol APU rulesHeathrow Airport – Operational Safety Instruction: Use of Aircraft Auxiliary Power Units. Rules on FEGP/PCA priority, permissible APU operating times, exemptions and monitoring.Heathrow APU Operational Safety InstructionFrench Government – APU restrictions at Marseille Provence Airport. Local operating limits, mandatory use of substitution equipment and reporting requirements concerning actual APU and alternative-equipment use.French APU regulation on LégifranceEUROCONTROL – Open-ALAQS. Airport local air-quality modelling covering sources including aircraft APUs and GPUs.EUROCONTROL Open-ALAQS