PCR Harpoon layout diagram

Structurally, the missile consists of four parts; instrument (head) and tail compartments, combat unit, marching engine.

In the instrument compartment, the nose section is covered with plastic fairing and an active radar homing head (PR-53/DSQ-28) is placed there. Next is the inertial guidance unit, followed by a radio altimeter (AN/APN-194), transmitting antenna altimeter and power supply converter. The inertial guidance head provides search, capture and pointing at the target. For protection against radio electronic suppression, its operating frequency value is changed by random law. Space is viewed by means of a disk-shaped phased antenna array, which can be rotated within +45° in vertical and horizontal planes. The homing head turns on at a given section of the flight path and starts searching for a target in accordance with the commands coming from the programmable scanning unit.

The Active Homing Radar Head (AHD) has a high resolution and operates in the range of 15.3-17.2 GHz (mass 34 kg, pulse power 35 kW). The detection range of a destroyer squadron with a probability of 0.95 when the missile is flying at low altitude and sea disturbance of 5 points is 40 km in clear weather and 23 km in rainy weather, and the missile boat is 18 and 10 km respectively.

The inertial guidance unit on the initial and marching sections of the flight path (mass 11 kg) consists of two main parts; a kardanless inertial device and a digital computer. This device includes three gyroscopes and three accelerometers, as well as other control and guidance devices that measure changes in the missile's spatial orientation. The IBM-4PSP-OA general-purpose computer with a permanent memory capacity of 7680 16-bit words and an operational device with random selection (512-word capacity) performs the functions of an autopilot, carrying out the control of the missile's flight on the initial and marching sections in accordance with the program set by the operator, the signals of inertial device and radio altimeter. It also provides control of the missile by CNS signals at the end of the flight path after target acquisition.

The short-pulse radar altimeter measures the missile's altitude above sea level, with the data entering the autopilot, which controls the set flight altitude. The transmitting antenna of the radio altimeter is located on the lower surface of the fuselage under the instrument compartment, and the receiving antenna - under the combat unit section.

The compartment of the combat unit (weight 230 kg, length 0.9 m) accommodates an ordinary blast charge in the armoured body, preventing its destruction when encountered with an armoured obstacle. The BC is equipped with a safety mechanism, an impact fuse and a non-contact fuse.

The marching engine compartment is equipped with a fuel tank and a turbojet marching engine (TRD). The fuel tank contains about 50 kg of liquid fuel JP-5 used for engine operation. A spring bellows is used to displace the fuel. In the front part of the compartment there are two silver zinc batteries (9 kg weight), which provide power to on-board instruments and are activated before the launch of the rocket. TRD J402-CA-400 (weight 44 kg, length 76.2 cm, thrust 273 kgf) has a single-stage turbine and a centrifugal compressor, as well as a ring-shaped combustion chamber. The engine is started by means of a pyrostarter, and in less than 7 s the rotor speed reaches 41,000 rpm. The engine provides flight at a cruising speed of 270-290 m/s (M=0.8-0.85), although it is possible to fly at a limiting speed of 374 m/s (M-1.1). TRD reliably operates at altitudes up to 12200 m, On the outer side of the compartment are air intake and wing consoles.

The tail compartment includes mechanisms and drives of the four steering wheels, as well as a support ring, to which the starter accelerator is attached using four breaking bolts. According to the signals of autopilot mechanisms through the drives provide steering wheel rotation by +30°.

A significant difference between the Harpoon AGM-84 aircraft rockets and other variants is the absence of a solid-fuel launch accelerator, due to which they have less starting mass and length. The accelerator (weight 137 kg, fuel mass 66 kg, thrust 6600 kgf) is attached by means of breaking pyrobolts to the supporting ring of the PKR body, its operating time is 2-3 s, it accelerates the rocket to the speed M=0.75. It is equipped with fixed aerodynamic stabilizers.