The missile's guidance is
inertial with mid-course updates from the launch aircraft, followed by a
terminal active radar phase from an acquisition range of about 20
. Work on the R-77 began in 1982, and the work was
considered quite significant and secret since it represented their first
fully multi-purpose missile for both tactical and strategic aircraft
for fire-and-forget employment against everything from hovering
helicopters to high speed, low altitude aircraft. Gennadiy Sokolovski,
Vympel Design Bureau General Designer, said that the R-77 can be used
also against medium and long range air-to-air missiles such as the
AIM-120 AMRAAM and AIM-54 PHOENIX as well as SAM's such as the PATRIOT.
Latest generation fighters are to utilize the R-77 from internal
carriage where the control fins and surfaces will fold flat until the
missile is catapulted clear of the aircraft for motor ignition.
During the initial flight phase
after launch, the R-77 is controlled by an inertial auto pilot with
occasional data link updates from the launch aircraft's radar on changes
in spatial position or G of the target. During the terminal phase, the
missile shifts to an active-radar mode. Over short distances, the
missile will launch in an active mode. The host radar system maintains
computed target information in case the target breaks the missile's
lock-on. If the seeker is jammed, it switches automatically to a passive
mode and homes on the source of jamming (HOJ).