What was the first delta wing produced by MiG's OKB?

Short answer

The Ye-4, the first prototype with the delta wing later carried by the MiG-21's production variants. It first flew on June 16, 1955. Earlier prototypes — the Ye-1, a 1954 preliminary design, and the Ye-2, born from its redesign — had swept wings. On the production wing, the leading edge is swept 57°.

Published: November 1, 2026 · Updated: November 1, 2026 · Edited by Above Ten Thousand · Editorial policy

What was the first delta wing produced by MiG's OKB?

Pair of Soviet MiG-21s in flight, view from below

From the Ye-1 to the Ye-2

The development of what would eventually become the MiG-21 began in the early 1950s, when Mikoyan's OKB completed in 1954 the preliminary design study of a prototype designated Ye-1. The project was reworked very soon after, once it was determined that the intended engine was underpowered, and that redesign led to the second prototype, the Ye-2. Both these and other early prototypes had swept wings.

The Ye-4 and the production delta wing

The first prototype with the delta wing found on the production variants was the Ye-4. It made its maiden flight on June 16, 1955. On the wing of the production versions, the leading-edge sweep angle is 57°.