Lockheed Martin and Korea Aerospace Industries have successfully completed the initial test flight of the second T-50A trainer aircraft, Lockheed announced Tuesday.

The tests for the aircraft, which is being offered in the U.S. Air Force's Advanced Pilot Training competition, took place in South Korea, Lockheed said in a statement.

Lockheed said it now has two aircraft in flight tests proving their upgrade, and are nearing completion of an assembly and training operations center to provide the Air Force with a production line and training capability immediately following the contract award.

The service's T-X program aims to replace the aging T-38 practical trainer aircraft.

The T-50A is low-risk and ready to go, Lockheed said.

It is based on the T-50, more than 100 of which are flying today.

Developed jointly by Lockheed Martin and Korea Aerospace Industries, the T-50A will train pilots to fly 5th-generation aircraft.

Lockheed is also offering a T-50A ground-based training system that features technologies delivering an immersive, synchronized platform.

The first T-50A completed its initial flight tests in June.