All earlier production versions of the aircraft had been equipped with the K-18 sight. The last twenty-four aircraft of this production run were equipped with the A-1C(M) gunsight, coupled to an improved ranging radar, the General Electric built AN/APG-30 installed in the nose above the intake.
As a result, many of them favored the clearly inferior, but dependable, K-18 sight, which continued in general use until the arrival of the F-86E, beginning in June 1951.
The first Sabres to arrive in Korea were the F-86A models, equipped with K-18 sights. These sights were soon found to be unsuited for the high-speed combat that ensued when MiG-15s were engaged.