9K33 Osa


The 9K33 Osa is a highly mobile, low-altitude, short-range tactical surface-to-air missile system developed in the Soviet Union in the 1960s and fielded in 1972. Its export version name is Romb.

Description

The Osa was the first mobile air defense missile system incorporating its own engagement radars on a single vehicle.
All versions of the 9K33 feature all-in-one 9A33 transporter erector launcher and radar vehicles which can detect, track and engage aircraft independently or with the aid of regimental surveillance radars. The six-wheeled transport vehicles BAZ-5937 are fully amphibious and air transportable. The road range is about 500 km.
The 1S51M3-2 radar system of the 9K33 Osa TELAR received the NATO codename Land Roll. It was derived from the naval 'Pop Group' radar system but is smaller as it does not require a stabilisation system. An improved system, the Osa-AKM was first seen in Germany in 1980. It had improvements to the launcher configuration, carrying six missiles in ribbed containers.
The system is reported to be of the frequency-agile monopulse type. It consists of an elliptical rotating surveillance antenna mounted on top of the array, operates in H band and has a 30 km acquisition range against most targets. The large pulsed J band engagement antenna is mounted below it in the centre of the array and has a maximum tracking range of about 20 km.
Mounted on either side of the tracking radar antenna is a small J band parabolic dish antenna to track the missile. Below it is a small circular antenna which emits an I band uplink capture beam to gather the missile shortly after launch. The final antennas in the array are two small white rectangular ones, one on either side of the array mounted alongside the I band, used for command uplink to the missile. The twin antenna system permits the 'Land Roll' radar to control up to two missiles simultaneously against a single target.
Two missiles can be guided on different frequencies to further complicate electronic countermeasures. The 9Sh33 electro optical tracker is fitted to and above the tracking radar, used to track the target when the main tracking radar is jammed by ECM.
A 9K33 battery comprises four 9A33B TELAR vehicles and two 9T217 transloader vehicles on BAZ-5939 chassis with reload missiles and a crane. A reload time of five minutes has been reported per TELAR.
In addition to the TELARs, each regiment is assigned a 9V914 radar collimation vehicle that assists in the alignment of the TELAR's radar systems, ensuring accurate target tracking and engagement.

Variants

  • 9K33 "Osa" began development in 1960 and was introduced in 1971–1972 with four exposed 9M33 missiles per 9A33B TELAR and maximum range of.
  • 4K33 "OSA-M" was introduced in 1972 and is the naval version of the system with two 9M33M missiles on a ZIF-122 retractable rotating launcher and improved performance. It has been installed on, Kara-class guided missile cruisers, Kiev-class VTOL cruisers and also the Kirov, Slava and Krivak classes.
  • 9K33M2 "Osa-AK" with 9A33BM2 TELAR was introduced in 1975 with the new six-missile box launcher, each 9M33M2 missile being a sealed round.
  • 9K33M3 "Osa-AKM" with 9A33BM3 TELAR and 9M33M3 missiles was introduced in 1980 with the maximum range extended to and maximum altitude to 12 km as explained above. Most OSA-AKM systems also feature an IFF antenna.
  • Saman and Saman-M is a development of the Osa\Osa-M system into target drones, used for testing and training with air defense systems, including SAMs.
The 9K33M3 is also able to use wire-guided missiles, presumably for use in an ECM-heavy environment where radio command guidance may not operate properly.

Missiles

Engagement range for early versions is approximately 2–9 km with engagement altitudes of between 50 and 5,000 m. The 9M33M2 "Osa-A" missile extends the ranges to 1.5–10 km and engagement altitudes to 25–5,000 m. The 9M33M3 missile greatly enhances the altitude engagement envelope to 10–12,000 m, and are able to travel further. However, the system is unable to engage targets at longer ranges, due to other factors such as the limitations of the radar tracking of the missiles. The system is designed for use primarily against jet aircraft and helicopters in any weather.
The 9M33 missiles are 3.158 m long, weigh 126 kg and use command guidance. A backup low-light optical tracking system is available for heavy ECM environments. The latest 9M33M3 missiles have an increased total weight of 170 kg in order to provide extended range coverage and larger warhead. Propulsion is provided by a dual-thrust solid fuel rocket motor. Both versions feature a missile speed of around Mach 2.4 for a maximum target engagement speed of around Mach 1.4 for the original 9M33 missile and Mach 1.6 for the 9M33M2\M3 missiles. The warhead for 9M33/M2 versions weighs 19 kg, increased to 40 kg in the M3 version to improve performance against helicopters. All versions have impact and proximity fuzes.
Each TELAR is able to launch and guide two missiles against one target simultaneously. Kill probability is quoted as 0.35–0.85 for the Osa and 0.55–0.85 for the Osa-AK and Osa-AKM. Reaction time is around 26 seconds. Preparation time for engagements from transit is around 4 minutes and missile reloading takes around 5 minutes. Each battery of four TELARs is usually accompanied by two reload vehicles carrying 18 missiles in sets of three, with a crane mounted on the reload vehicles to assist in moving the missiles.
When launched, the booster motor burns for two seconds, permitting the radar to gather and control it at very short ranges. The sustainer motor burns for 15 seconds, bringing the missile to a top speed of about Mach 2. Once launched, the missile is command-guided for the whole flight, and the warhead is detonated by its proximity fuze or possibly command. The warhead is said to have a lethal radius of 5 m at low altitude against an F-4 Phantom II size target.

Radars

Produced by the Soviet Union/Russia, the system was exported to many countries, including Cuba, Greece, Poland, Syria, Ecuador and Iraq.
During the 1982 Lebanon war in which Syrian air defenses were obliterated by a massive air campaign against Syrian SAM sites in the Beqaa valley, the Syrians deployed Osas. An F-4 Phantom in a SEAD mission was shot down on 24 July 1982 by an Osa system. The WSO, Aharon Katz was killed, while the pilot, Gil Fogel, survived and was held captive by the Syrians for two years.
In the late 1980s, Cuba deployed several 9K33 Osa units in southern Angola, which posed a significant threat to South African air superiority at shorter ranges. The South African 61 Mechanised Battalion Group captured an intact 9K33 Osa anti-aircraft missile system on 3 October 1987 during the Battle of Cuito Cuanavale. This was the first time that such a system had fallen into possession of non-Warsaw Pact forces, giving Western intelligence agencies an opportunity to examine an important Soviet-bloc weapon system.
Iraq fielded Osa systems during the 1991 Gulf War. The Soviets claimed that it was the most effective system alongside the ZSU-23-4 Shilka at shooting down Tomahawk cruise missiles, with several downings credited to hits from Osa weapons.
The system also saw use in the 2008 Russo-Georgian War by both the Georgian and Russian militaries.
Libya deployed 9K33 Osa, with some destroyed during the 2011 Libyan Civil War by NATO airstrikes.

Syrian Civil War

In October 2012, fighters from insurgent faction Liwa al-Islam captured three operational 9K33 Osa mobile SAMs in Damascus' Eastern Ghouta. In the following years, at least six missiles were launched at helicopters from the Syrian Arab Air Force flying over the area: on the 29th of July 2013, a Mi-8/17 was apparently destroyed; a second launch, whose result is unclear, occurred at an unknown date in the following months; on 16th of January 2014, a Mi-17 was shot down; two days later, another missile missed its intended target; an undated video released in March 2014 by Jaysh al-Islam showed a 9M33 missile exploding in the proximity of a Mi-8/17. In October and December 2015, the Russian Ministry of Defence claimed its forces had destroyed Osa systems operated by the insurgents in the Eastern Ghouta. No further launch was reported until the 26th of June 2016, when a missile heavily damaged a Mi-25, forcing it to make an emergency landing at Damascus International Airport. All of Jaysh al-Islam's Osa systems were likely retaken, or destroyed, upon the Syrian Arab Army's recapture of the Eastern Ghouta in April 2018.

Yemeni Civil War

On 29 November 2019, Russian sources speculated a Soviet-made 9K33 Osa fired by Houthi forces shot down a Saudi Arabian Army Aviation AH-64 Apache in Yemen. Neither Yemen nor Iran had any 9K33 Osa in their armed forces, while known Houthi-operated systems are based on the Soviet-made 2K12 Kub surface-to-air missile system which employs a two-stage rocket engine, and the air-to-air missiles R-73 and R-27T which both have a single-stage rocket engine.

2020 Nagorno-Karabakh conflict

The Armenian Air Defense extensively employed 9K33 Osa missile systems during the 2020 Nagorno-Karabakh conflict. During the opening days of the war, several videos released by the Azerbaijani military showed several Armenian 9K33 Osa and 9K35 Strela-10 vehicles destroyed by Bayraktar TB2 armed drones, with a number of them destroyed in the following weeks when found on the battlefield. Twelve 9K33 Osa missile systems of Armenian Army were destroyed during the Nagorno-Karabakh conflict by Azerbaijani Bayraktar TB2s.
On 4 October 2020, an Azerbaijani Air force Sukhoi Su-25 aircraft was shot down by Armenian forces, probably by a 9K33 Osa while targeting Armenian positions in Fuzuli. The pilot, Colonel Zaur Nudiraliyev, died in the crash. Azerbaijani officials acknowledged the loss in December 2020, with the 9K33 Osa vehicle possibly using passive detection and shoot and scoot tactics to survive the Azerbaijani suppression of air defenses missions.