The Supreme Court in the Netherlands has upheld a ruling that a plan to cut slots at cargo hub Amsterdam Schiphol Airport was unlawful.

This decision follows something of a battle between the government, the International Air Transport Association (IATA) and airlines since the Dutch government's "experimental regulation" to cut flight numbers at the airport from 500,000 per year to 452,500 was proposed in 2022 to address noise and environmental pollution.

In March last year, the International Air Transport Association (IATA) and airlines began a legal challenge over the Dutch government’s decision to reduce capacity at Schiphol, owned and operated by Royal Schiphol Group and itself majority owned by the government.

The following month saw the Amsterdam District Court uphold the legal challenges lodged by IATA, KLM and other airlines against the Dutch government’s plan, ruling it was not in compliance with the EU "Balanced Approach" procedure for noise management.

But then in July 2023, the Dutch Appeal Court overturned the court decision, prompting airlines and industry associations to prepare for cassation proceedings against the judgement.

This, however, was followed by a decision by the Dutch government four months later to suspend its plans to cut flights at the airport after after objections from the US and European Union.

Now the Supreme Court has ruled that any measure leading to a reduction in the number of aircraft movements at Schiphol must go through the balanced approach procedure in line with European legislation.

"The Supreme Court rules that the court of appeal wrongly decided that the proposed measures are exempt from the procedure of the balanced approach prescribed by European rules,” said the Supreme Court in a statement last week, reported by Air Cargo News' sister airline FlightGlobal.

IATA said it welcomed the decision and that the Balanced Approach should not be dismissed. Willie Walsh, IATA’s director general, said: “We welcome this decision from the Supreme Court, affirming the original decision of the Amsterdam District Court that the unilateral cuts to flight numbers at Schiphol were unlawful, and overturning the Court of Appeal.

"There is an internationally-agreed means of managing airport noise – the Balanced Approach – which protects the national and regional benefits of air connectivity while helping to mitigate noise impacts for local residents.

"We expect the new Dutch Government will respect today’s decision and proceed to apply the Balanced Approach, which is also enshrined in EU law and international treaties, with the utmost care with regards to Schiphol.

"Furthermore, we hope any other government thinking of disregarding the Balanced Approach will take note of this decision. It is a proven and successful process and should not be ignored."

KLM said in a statement: "KLM supports the Supreme Court's clearly substantiated ruling. KLM wants to continue to connect the Netherlands with the rest of the world in balance with the environment. To this end, we have drawn up the cleaner, quieter and more fuel-efficient plan, which shows that the common goal of reducing noise pollution can be achieved without reducing the number of aircraft movements."