Bisnovat design bureau presented two R-40 missiles in 1962, the semi-active radar guidance R-40R and the infrared guidance (IR) R-40T. The radar guide variant was designed with an inverse monopulse seeker that allowed it to be launched from any position and height respect to its target, making it extremely effective. The missile has 4 canards and 4 large control fins to be able to maneuver at high altitude, and has a huge warhead that ensures enough power to destroy a target flying at more than 20,000 meters high and at a speed of Mach 3, planned for the American XB-70 bomber.The AA-6 Acrid missile is the largest air-to-air missile that has entered service with the IR variant almost 6 meters long and the radar guidance variant more than 6 meters long. The warhead can vary between 38 and 100 kg in weight and the range is about 50 km for the IR version and about 80 km for the radar version. The missiles work in conjunction with the Smerch-A (Fox Fire) radar that has range of about 160 km and has a continuous wave transmitting antenna and a receiver that is installed on the tip of the interceptor’s wings. These missiles had to be modernized due to the defection of a Russian pilot aboard a Mig-25 in 1976, the improved missiles carry the suffix “D” and have better sensors and improved infrared ECMs.R-40 missiles have a large-combustion engine that uses solid propellant that allows a speed around Mach 4 to 4.5 (4,900-5,500 km/h). Although the missile was developed exclusively for the Mig-25P aircraft, the Mig-31 Foxhound fighter has also been seen with them. Normally 4 missiles are loaded in each interceptor, 2 infrared guidance and 2 radar guidance, and the tactic of always firing one missile of each type at the target is used. First the infrared is fired and then the radar, in this way it is avoided that the infrared missile can shoot down its fellow radar guide missile.AA-6 Acrid missiles were exported to several Arab countries and India. Although the Soviets have never used them in combat, some Arab countries have, and quite effectively. It seems that in 1981 Syrian Mig-25PD shot down an Israeli F-15 fighter, although this has never been officially confirmed by Israel. On January 17, 1991 an American F/A-18C was shot down by an Iraqi R-40R missile launched by a Mig-25, as indicated in a report declassified by the CIA. Also on January 30, 1991 Iraq claims that one of its Mig-25s shot down an American F-15 with an R-40 missile during the Sammurra Air Battle. Although this shot down is not recognized by the USAF, the truth is that a Bedouin found remains of an F-15 in the area where Iraqi radars lost track of an F-15 falling on that date. These last two actions were carried out within Operation Desert Storm.
