Question to the Ministry of Defence:

To ask the Secretary of State for Defence, what recent progress his Department has made on exhaust emissions tests on in-service helicopters.

The Ministry of Defence has previously conducted multiple sampling surveys on the, now out of service, Sea King helicopter between 1999 and 2015. These previous surveys found no conclusive evidence to suggest that aircrew were subject to exposure levels above UK and international safety standards.

In response to recent concerns regarding the emissions of out of service helicopters, including the Sea King and Wessex, the Ministry of Defence has commenced a programme a programme of exhaust emission substance sampling for its in-service helicopter fleet.

Modern helicopters and their engines are developed and certified to recognised standards with stringent emissions requirements and there is no current evidence to suggest personnel are at risk from current in-service helicopters. We are proactively conducting this work to ensure we are meeting our legal duty of care to our people. It is vital we can reassure them of their safety while at work.

The testing programme commenced in February 2025 and is ongoing. Throughout, we are balancing the need to conduct testing with the operational requirements and availability of the aircraft.