Norway will return the NH90 military helicopters bought from France’s NH Industries because they are either unstable or were delivered late, the defense minister and military chief announced on Friday.

The government also stated that it will pursue repayment of 5 billion crowns ($523 million), plus interest and other fees, from NH Industries, which is owned by Airbus Helicopters, Italy’s Leonardo, and the Netherlands’ Fokker Aerostructures.

NH Industries did not respond quickly to requests for comment.

“Regardless of how many hours our specialists spend or how many components we order, the NH90 will never be capable of satisfying the needs of the Norwegian Armed Forces,” Defense Minister Bjoern Arild Gram said during a press conference.

The original contract for 14 helicopters was signed in 2001 but Norway has received only eight, the ministry said.