TAIPEI (Taiwan News) — The new domestically made “Brave Eagle” Advanced Jet Trainers (AJT) will drop concrete bombs off the coast of Taichung City in the latest phase of pilot training, reports said Friday (June 10).

Concrete bombs contain dense, inert material, often concrete, instead of explosives, and are used for training purposes. Taiwan’s Air Force is in the process of replacing its F-5 training jets built in the United States with 66 Brave Eagles produced by the Aerospace Industrial Development Corporation (AIDC).

The first group of pilot trainees has completed its work with the new indigenous aircraft, but no bombing exercises had been conducted so far, CNA reported. The Air Force decided to stage mock bombings between June 23 and July 6 with jets dropping 500-pound (227 kilograms) concrete bombs into the sea near Taichung, between 10 and 11 a.m., and 2 and 3 p.m., with two to four bombs each day.

While the F-5 will be phased out by the end of 2024, only 45 of the “Brave Eagles” are expected to be in service by then. This includes 33 at Chihang Air Force Base in Taitung County and 12 at the Gangshan base in Kaohsiung City.