Question to the Department for Transport:

To ask the Secretary of State for Transport, if his Department will take steps to assess whether tests for (a) carbon dioxide, (b) nitrogen oxide and (c) other emissions from aero-engines reflect real-world conditions of use.

The certification of aero-engines is primarily the responsibility of the certification authority for the state of manufacture. In Europe this is the European Aviation Safety Agency (EASA) who also have oversight of engines certified in other regions that expect to be registered in the UK or any other European country. We are in discussion with EASA as to how we might be reassured that the results for aviation certifications are robust. The certification requirement for Oxides of Nitrogen (NOx), Carbon Monoxide and unburnt hydrocarbon is based on operating the engine on a test bed at different thrust settings to simulate the landing and take-off phases of flight below 3000 feet. The visible smoke test identifies the worst case condition for smoke. A new standard for CO2 emissions from aircraft is being developed and is expected to assess the cruise emissions as this phase dominates total fuel burn. EASA certification engineers would verify the fuel burn on tightly controlled test flights. The Secretary of State informed the Transport Select Committee on 12th October that the current focus of the Government’s investigation into the use of defeat devices is focussed on cars and light commercial vehicles.