Question to the Ministry of Defence:

To ask the Secretary of State for Defence, whether any F-35 jets have been affected by harmonic resonance issues with their engines; and what steps he is taking to resolve these engine issues.

No aircraft from the UK's operational F-35 Lightning fleet have been identified as being at risk of experiencing harmonic resonance, but a small number of aircraft in production for the UK were identified.

In early March 2023, the F-35 Joint Program Office authorised a modification to mitigate the harmonic resonance issue. This has been fitted to the UK aircraft due to be delivered off the production line, and will be implemented across the entire UK fleet.