The US Air Force (USAF) T-X programme, aimed at replacing the ageing Northrop Grumman-built T-38C Talon fleet, has been delayed further due to the US Department of Defense’s latest budget proposal.

According to the Air Education and Training Command (AETC), the DoD 2013 budget proposal has postponed the T-X programme initial operational capability from 2017 to 2020, while the contract award has been delayed by one year to 2016.

The aging T-38Cs entered into service with the USAF 51 years ago and are now unfit to carry out certain functions, such as in-flight refuelling and aerial manoeuvres beyond 5gs that are required to train pilots.

The USAF is currently using Lockheed-built F-16 aircraft to train pilots for F-22 and F-35 aircraft to fill the potential training gap for pilots moving from the T-38 to the F-22, reported Flightglobal.

The demand for the trainer is likely to increase further with the F-35 expected to enter the USAF fleet by the end of the decade.

BAE has teamed up with L-3 Link to offer the Hawk AJTS Ground-Based Training System (GBTS) for the programme, having previously formed a strategic partnership with Northrop for the same programme in September 2011.

The Hawk AJTS aircraft will serve as the future lead-in trainer for the F-35 aircraft for the US Navy and US Marine Corps (USMC) as well as in the UK, Canada and Australia.

Other potential contenders include Alenia Aermacchi with its M-346 Master, and the T-50 Golden Eagle by the Lockheed Martin/Korea Aerospace Industries team.

The USAF has plans to procure 300-350 new aircraft in addition to the current fleet of more than 500 T-38s.