Defence

Iran's long-rumoured steps to develop an indigenous fighter aircraft have taken form in what appears to be a radically altered version of the US Northrop F-5E Tiger, which has been in use with the Iranian air force for more than 30 years.

Iranian media released a low-quality image of the aircraft - dubbed Sa'egheh (Thunder) - following a successful test flight from Hamedan air base on 8 July.

The image shows an aircraft similar in appearance to the F-5, although it features a revised "butterfly" tail configuration in place of the F-5's original vertical tail surface. While the aircraft's horizontal stabilisers have been retained on another published image of a model, they cannot be distinguished in the new photograph. Its engine intakes also appear to introduce a raked configuration.

The reasons for the design modifications are unclear, but could indicate a desire to develop an aircraft with lower drag, enhanced manoeuverability and potentially a reduced radar cross signature. The aircraft was not pictured in flight.

Iran's aviation industry has previously conducted work to overhaul and modernise ageing US-sourced equipment such as the air force's legacy fleets of F-5s and Grumman F-14A fighters. It has also conducted work to enhance the capabilities of the Iranian army's ageing fleet of Bell AH-1 attack helicopters.