YJ-8 (C-801) Anti-Ship Missile

Last updated: 9 July 2007

The YingJi-8 (YJ-8; Export name: C-801; NATO Codename: CSS-N-4 Sardine) anti-ship missile was developed by China Haiying Electro-Mechanical Technology Academy (CHETA, also known as 3rd Space Academy) in the 1970s. Initially developed as an air-launched anti-ship missile, the YJ-8 later evolved into a family of anti-ship and land-attack cruise missiles for air, ship, land, and submarine launches. The missile replaced the ageing HY-2 (C-201) to become the standard ship-to-ship missile on almost all Chinese-built surface combatants since the early 1990s.

In 1970, 3rd Space Academy (now CHETA) was asked by the PLA Navy to develop a subsonic, sea-skimming, solid-propellant anti-ship missile that could be fired from a Nanchang Q-5-size attack plane. The missile design proposal was submitted by 3rd Space Academy in 1973. The first long-endurance solid rocket motor needed to power the missile was introduced in October 1973, and the design of the rocket motor was finalised in late 1977. The anti-ship missile development programme was officially approved by the State Council and the Central Military Commission in September 1977 under the designation YingJi-8.

By the late 1970s, 3rd Academy had already completed the development of most key components required by the YJ-8 missile, including two types of radio altimeter, mono-pulse terminal guidance radar, semi-armour-piercing high-explosive warhead, and time-delayed fuse with three independent safety mechanisms. By adopting analogue electronic technology, the missile designer was able to reduce the size and weight of the onboard equipment significantly, enabling the missile to be small and light enough for air launch.

In August 1978, the PLA Navy examined the proposal of fitting the Nanchang Q-5 (Fantan) attacker aircraft with the YJ-8 anti-ship missile. The first YJ-8 missile was completed in the same year. Between 1978 and 1981, the YJ-8 missile was successfully test fired from land-based launcher in unguided, inertial guidance, and radar-homing modes. These tests enabled the designer to identify design flaws and technical problems before the missile design could be finalised.

As the development of a modified Q-5 variant to carry the YJ-8 missile was delayed, it was decided that the missile was to be test fired from a missile fast attack craft (FAC) first. The first sea-based test fire of the missile in 1984 failed when two of the three missiles fired lost control before reaching the targets. Poor reliability of the onboard components was identified as the reason for the failure. The modified missile was tested again in 1985, with the missile directly hitting the targets in all six launches. The YJ-8 missile was certified for design finalisation in 1987. In September 1987, the YJ-8 was test fired from a Type 053H2 (Jianghu-III class) missile frigate. The existence of the YJ-8 missile programme was first confirmed when the missile was displayed during the parade in Beijing on 1 October 1984 to celebrate the 35th anniversary of the PRC.

Unlike previous Chinese indigenous anti-ship missiles, which were all derivations of the Russian 544 (SS-N-2 Styx) anti-ship missile, the YJ-8 was developed from scratch with certain Western influence. The YJ-8 is almost identical in length and diameter to the French Exocet anti-ship missile, and features a triple control surface similar to those found on the U.S. Harpoon. There has been speculations that the YJ-8 may have been based on Exocet, but this claim appears to be groundless.

Design

The YJ-8 features a slim cylinder body with round nose, trapezoid wings and stubby fins near the end of the body. The nose section consists of a mono-pulse, high-frequency (possibly J-band) terminal guidance radar seeker with a 165kg time-delayed semi-armour-piercing warhead behind it. The instrument compartment containing the guidance command processor, vertical gyro, radio altimeter and its antenna, is located in front of the rocket motor.

The terminal guidance radar with mono-pulse system possesses high anti-jamming capabilities. The high precision radio altimeter allows the missile to have minimum-altitude flight above the sea. It uses a semi-armour-piercing anti-personnel blast warhead which relies on the missile's kinetic energy to pierce the deck of a ship, penetrate into and explode in the ship's interior. During final design flight tests, one missile sank a target ship of 10,000t displacement.

Launcher/Storage Container

The basic version of the YJ-8 is carried inside a box-shape storage container, which also serves as the launcher. The container is 6m X 1.16m X 1.3m in dimension and 1,000kg in weight. The missile is locked on a launch rail inside the container using a safety mechanism. The container is airtight and filled with dry air to protect the missile from the dampness in the maritime environment. The lid of the container is hydraulically operated in non-operational status and blasted off immediately before the firing of the missile. The container can be reused after the launch.

Later variants of the YJ-8 is fired from a new launcher/storage container that is able to handle YJ-8, YJ-8A, and YJ-83 missiles. The new container has become standard on all Chinese-built surface combatants.

Flight Profile

When the search radar onboard the surface ship detects a target, the radar tracks the target while the fire-control system calculate the firing parameters such as flight altitude and missile guidance radar switch-on time according to the movement of the target and wind speeds and directions. Once the parameters are inputted into the YJ-8 missile, and the pre-launch check is completed, the missile is ready for launch. The carrier ship will then adjust its direction to have the target within the YJ-8 missile’s off-boresight range.

Once the target is within the missile’s operational range (8~40km for basic variant YJ-8), the missile is launched from the carrier ship. The solid rocket booster burns out within few seconds, accelerating the missile to the cruising speed of Mach 0.9 before it is detached from the missile. The main rocket motor then ignites to keep the missile flying at the cruising speed. At this stage the missile flies under the inertial autopilot system and radio altimeter, maintaining an altitude of 20~30m depending on the sea status.

When the missile approaches its target, the onboard terminal guidance radar switches on and scan for the target. Once the target is captured, the missile flies directly towards the target and dives to 5~7m altitude several kilometres away from the target. Shortly before the missile hits the target, it dives again to hit the waterline of the target to cause maximum damage.

Variants

Specifications

Length: 5.814m
Diameter: 0.36m
Wingspan: 1.18m
Launch weight: 815kg
Warhead: 165kg time-delayed semi-armour-piercing high-explosive
Propulsion: One solid rocket engine, one solid booster
Max speed: Mach 0.9
Range: (ship-to-ship) 8~40km; (air-to-ship) 10~50km
Flight Altitude: 20~30m (flight); 5~7m (attacking)
Guidance Mode: Inertial and terminal active radar
Single-Shot Hit Probability: 75%

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