Missile Derby

The Derby, also designated as the Alto, is a beyond-visual-range (BVR) missile developed as an enlarged version of the Python-4. In 2015, an extended-range variant designated I-Derby ER was confirmed following the cancellation of a version based on the Stunner missile.

The missile utilizes active radar homing for terminal guidance. Propulsion is provided by a solid fuel rocket motor. The I-Derby ER variant incorporates a dual-pulse solid rocket motor, which employs a secondary energy pulse as the missile nears the target to extend flight time. This variant also features an integrated sensor and fusing system that combines the seeker and fuse components. The missile is designed for medium-range engagements and is also utilized as a surface-to-air interceptor within the SPYDER air-defense system.

The missile is operated by several countries, including Brazil, Chile, Colombia, Ecuador, and Singapore. It is deployed as part of ground-based air-defense systems by Georgia, the Philippines, and Vietnam. The Indian Air Force selected the missile for the HAL Tejas and planned to integrate the I-Derby ER on its Sukhoi Su-30MKI fleet to replace R-77 missiles. The Czech Republic is a future operator of the I-Derby ER. South Africa previously operated the system under the local designations R-Darter or V4. Launch platforms include various aircraft such as the F-16, JAS 39 Gripen, and F-5E/F Tiger II.