Air Incheon (KJ, Seoul Incheon) has transitioned to an all-B737NG fleet following the retirement of its last B737-400(SF) in late September.

HL8271 (msn 24912), a 30.4-year-old aircraft originally delivered in a passenger configuration to Malaysia Airlines in 1991, was last tracked operating flights in South Korea on September 28, 2021. Air Incheon had used the freighter since 2013 and was its first post-conversion operator. Over the course of October 2-5, 2021, the aircraft was ferried to the United States. It has been acquired by Frontera Flight Holdings and was re-registered as N73FF on October 14, 2021. It is currently in storage at Laredo and will be operated by Mexico's Aeronaves TSM, a sister company of Frontera.

The Korean cargo carrier operated another B737-400(F) but retired it in 2019, the ch-aviation fleets history module shows.

Air Incheon has replaced the retired -400(SF) with its third B737-800(SF), HL8503 (msn 28535). The 21.8-year-old aircraft, on lease from Vx Capital Partners, was delivered to Seoul Incheon on October 21 and operated a test flight around the city on October 27 but has yet to be deployed into revenue service. The airline, which is currently up for sale by its current owners, began B737NG operations earlier this year.