19 January 2023

Put to the test: KF-21 prototypes to sequentially expand flight trials

by Akhil Kadidal

This third prototype of South Korea's KAI KF-21 jet fighter conducted its first test flight on 5 January 2023. The prototype will explore a wider range of the aircraft's flight capabilities. (DAPA/KAI)

Korea Aerospace Industries' (KAI's) KF-21 fighter jet prototypes will be undertaking more rigorous flight-testing to reveal greater details about the performance and capabilities of the new jet.

KAI has three flight-worthy prototypes of the 4.5-generation combat aircraft in operation. Flight-testing of the first KF-21 started in July 2022, and by 19 January the three operational prototypes had conducted more than 80 flights, South Korea's Defense Acquisition Program Administration (DAPA) said. On 17 January, the KF-21 conducted its first supersonic flight.

A DAPA spokesperson told Janes that this prototype achieved a maximum speed of Mach 1.05 at 1515 h local time. “Supersonic speed was achieved at [nearly] 40,000 ft, some 300 km south of Seoul, over the south coast,“ the spokesperson said.

A video of the flight released by DAPA shows that the supersonic flight was conducted by the first KF-21 prototype. DAPA said the flight showed that “structural stability of the aircraft can be maintained at high speeds“. The latest prototype, KF-21 No 3, will be used to expand the aircraft's flight envelope, DAPA said.

Three additional prototypes, which will further enlarge the scope of flight-testing, are scheduled to start flying in 2023. DAPA said each prototype will have a different “core” role. “While all prototypes conduct basic tests such as stability, handling quality, etc ... certain test areas will be assigned to each prototype by its role for the test efficiency,” the spokesperson said.

Korea Aerospace Industries' (KAI's) KF-21 fighter jet prototypes will be undertaking more rigorous f...

Jane's Find unrivaled intelligence, consultancy and advertising solutions to the defence and national security sectors.