control surfaces (similar devices are used on the OTR-23 Oka, and USAF uses them on MOAB). The flow separation which occurs at high angles of attack enhances its turning ability, giving the missile a maximum turn rate of up to 150° per second. However, the grid fins also increase drag and radar cross section. Updated variants of the R-77, such as the izdeliye 180 that is destined for the Sukhoi Su-57, will use conventional fins instead. The missile uses a multi-function doppler-monopulse active radar seeker developed by OAO Agat. The radar features two modes of operation, over short distances, the missile will launch in an active "fire-and-forget" mode. Over longer distances the missile is controlled by an inertial guidance auto pilot with occasional encoded data link updates from the launch aircraft's radar on changes in spatial position or G of the target. As the missile comes within of its target, the missile switches to its active radar mode. The host radar system maintains computed target information in case the target breaks the missile's lock-on. Operational history At the beginning of February 2016, four Su-35S were deployed to Syria as part of the Russian aerial expeditionary force to the country. Tasked with air to air duties, the Su-35S were extensively documented while armed with a couple of R-77 missiles, between IR seeking R-27T under the inner pylons and R-73 under the outer ones. Variants R-77 (izdeliye 170) – Standard model. RVV-AE (izdeliye 190) – Export model of the R-77. The missile has a maximum range of with 22.5 kg warhead. R-77-1 (izdeliye 170-1) – Russian-built variant with a streamlined nose, 9B-1248 (Izdeliye-50-1) active radar seeker head, and new fins. RVV-SD – Export model of the R-77-1. The missile has a maximum range of with 22.5 kg warhead. R-77P / RVV-PE – Passive homing model. R-77T / RVV-TE – Infrared homing model. R-77-SRK – Ship-to-air variant. R-77-ZRK / RVV-AE-ZRK – RVV-ZRK Surface-to-air variant. R-77-PD / RVV-AE-PD – Ramjet model. R-77-PD ZRK / RVV-AE-ZRK – RVV-(PD-)ZRK Surface-to-air variant. K-77M (izdeliye 180) – Version under development for the Sukhoi Su-57 with AESA seeker, conventional fins, and two-pulse motor. K-77ME (izdeliye 180-BD) – Ramjet model of the K-77M. Operators Current operators – for the MIG-29M/M2 and Su-30MKA – unknown number bought in 2013 – 300 for the MIG-29M/M2 and Su-35 – for the Su-30MKK and Su-30MK2 People's Liberation Army Air Force People's Liberation Army Naval