Deliveries of Boeing aircraft to China are currently paused pending a review of batteries that power their onboard cockpit voice recorders (CVR), Reuters has reported citing internal sources.

The review is related to the installation of new CVRs capable of storing 25 hours of data, up from the previously mandatory two hours. The US Congress mandated the change in its FAA reauthorisation bill, which entered into law on May 16, 2024. The bill requires that all aircraft manufacturers after one year from the law's enactment must be equipped with the new CVRs. All aircraft with earlier versions of the recorders will have to be retrofitted within six years. The US law follows that of the European Union Aviation Safety Agency (EASA), which has had a 25-hour minimum in force since January 1, 2021.

"We defer to the FAA and the Civil Aviation Administration of China (CAAC) on this regulatory discussion," Boeing said while confirming the delay. The manufacturer emphasised that the 25-hour CVR had already been approved by the FAA and accepted by EASA. There is no evidence of any new quality issues causing the delay.

The ch-aviation fleets module shows that Boeing delivered 23 aircraft to Chinese operators in 2024, including twenty-one B737-8s and two B787-9s. The last B737 MAX delivery was on April 29, 2024, to Hainan Airlines. The only aircraft delivered in May, B787-9 B-20EL (msn 63987), to China Southern Airlines, was built in 2020 but only ferried to China on May 12, 2024.

Boeing was not allowed to deliver any B737 MAX to China between the type's March 2019 grounding and the end of 2023. At the end of 2023, it had around eighty-five B737 MAX outstanding for Chinese customers.

The US National Transportation Safety Board (NTSB) has been pushing for extended CVR storage capabilities for years, as the previous two-hour limit hampered multiple accident and incident investigations. Most recently, the NTSB said it lacked the necessary CVR data for the January 5, 2024, Alaska Airlines incident, when a cabin door plug blew out of a B737-9 mid-flight.