Taiwan's Air and Missile Defence. Part 5: Short-range air defence of ROC Army

Taiwan’s Conventional Defence Series: Introduction

A major armed conflict across the Taiwan Strait would cause significant disruptions to the global economy and have serious geopolitical consequences. Despite persistent calls for Taiwan to enhance its asymmetrical warfare capabilities, information on Taiwan’s defence capabilities has often been outdated and incomplete. Additionally, Taiwan’s conventional deterrence is frequently overlooked in discussions of its security, particularly in the broader context of China-US relations.

This series aims to provide a clearer understanding of Taiwan’s defence capabilities and contribute to the discourse on defence and the wider geopolitical issues surrounding Taiwan. It begins by exploring Taiwan's core defence capabilities, such as air defence, sea control, counter-strike and C4ISR (Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance). The series will then examine the development and outlook for Taiwan’s main military branches, followed by discussions on other relevant topics, including military exercises, defence spending, recruitment, and arms development and procurement.

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Short-range air defence

ROC Army 

Currently, responsibility for Taiwan’s low-altitude air defence rests primarily with the ROC Army, which:

●    Has established an integrated short-range air defence network, centered around the domestic “Bee Eye” radars and US Stinger missiles. The recent addition of ground-launched Tien Chien-2 missiles increased defence coverage and resilience to counter measures.

●    Has a substantial and growing inventory of short-range surface-to-air missiles (around 5000 Stinger missiles by 2031 if delivery is on time). This missile-based air defence is well-suited to countering airborne assaults and traditional aerial threats such as high-value aircraft and subsonic land-attack cruise missiles.

●   Has taken few concrete measures to address the emerging and disruptive threats such as mass-deployed One-Way-Attack drones and loitering munitions. This capability gap is further exacerbated by a lack of non-missile air defence assets.

 

1. Bee Eye Radar

a. Brief development and procurement history

In 1999, the National Chung-Shan Institute of Science and Technology (NCSIST) started to develop a short-range radar that is able to provide target acquisition data for the ROC Army’s US Avenger short-range surface to air missiles (SAMs). After several years of delay, the NCSIST’s CS/MPQ-90 “Bee Eye” passive electronically scanned array (PESA) radar passed initial combat evaluation in 2008. The procurement of the Bee Eye radar started in 2011, with a total of 34 radars scheduled for delivery under three ROC Army orders from 2012 to 2026 (Table 1).

 

Table 1: Army’s procurement of CS/MPQ-90 Bee Eye radars. Sources: Legislative Yuan, MND 2021 budget, MND 2022 budget

Within the ROC Army, the Bee Eye radar is likely also referred to as the “Eagle Eye” radar.^[1] With each delivery batch, the radars received further upgrades and/or modifications.^[2]

b. Specifications

With a high level of automation, the Bee Eye radar could (1) detect and track low flying targets, (2) provide target acquisition for various short-range surface to air missiles, and (3) form an integrated air picture to increase air defence effectiveness. In many aspects, the radar is roughly comparable to the US MPQ-64 Sentinel (Table 2).

 

Table 2. Comparison between Bee Eye and Sentinel. Sources: ROC Army Artillery Quarterly, Ewmib, Sofrep, Note: The third batch of 11 Bee Eye radars deployed on off-shore islands might have switched to trailer-style platforms to better fit island terrain.^[3]

 

When working in conjunction with the Avenger SAM, both radars could steer the turret of the Avenger toward the selected target under the Slew-To-Cue (STC) mode. Reportedly, the Sentinel radar’s STC mode increases engagement opportunities of the Avenger by 55% and hit rate by 66%. However, early Sentinel radar can only steer Avenger’s turret on the azimuth plane, and the operator must manually aim at the target on the elevation plane. Bee Eye radar’s STC mode steers Avenger’s turret toward the selected target on both azimuth and vertical planes, further increasing engagement efficiency (Figure 1).

Figure 1. Automatic Slew-To-Cue engagement process. The radar operator’s console is located inside the command and control vehicle to reduce the risks to personnel posed by enemy anti-radiation missiles.

 

Low altitude air defence is often obstructed by terrains and buildings. To overcome this difficulty the Bee Eye radars can be assigned to different sectors simultaneously. Radar intelligence is transmitted to and shared among different radar command and control vehicles. This enables data integration, system redundancy and the creation of an integrated air picture (Figure 2).^[4]

 

Figure 2. The command and control vehicles of the Bee Eye radars can automatically incorporate radar intelligence from (1) other Bee Eye radars, (2) other Bee Eye command and control vehicles, and (3) higher-echelon command, to increase situational awareness and interception opportunities. Source: ROC Army Artillery Quarterly

 

2. Surface to Air missiles (SAMs)

a. Stinger missiles

Since the 2000s, Taiwan armed forces have been taking deliveries of the US Stinger missiles in different batches and forms (Table 3).

Table 3: Taiwan’s procurement of Stinger missiles. *“Cost associated with each missile” does not represent a missile’s unit price, and is added only to provide a rough reference for the procurement cost, which is heavily influenced by inflation, demands and supply, and scope of the procurement (i.e., in some cases logistical support and training equipment may be included).

Source: Youth Daily, Congressional Research Service, CTS, Liberty Times, Taipei Times, 2025 defence budget

 

The ROC Army is the primary operator of Stinger missiles in Taiwan, with the latest addition of man-portable Stingers further enhancing the survivability of mobile air defence units. It also provides the infantry with flexible means to counter helicopter landings or other airborne troop deployments (Figure 3).

 

Figure 3. Man-portable Stinger missiles, operated by army special forces (Left) and Military Police (Right), made its debut in Taiwan during the 2025 Han Kuang annual military exercises. Images: MNA, The Storm Media

 

b. Ground-launched TC-2

The ground-launched Tien Chien-2 (Tien Chien means “Sky Sword,” and the ground-launched variant is also commonly referred as Lu Chien, meaning “Ground-launched Sword”) is a further development based on the Tien Chien-2 mid-range air-to-air missile, which was put into service along with Taiwan’s Indigenous Defence Fighter (IDF), the F-CK-1, in the mid-to late-1990s. On paper, the TC-2 is comparable to early versions of the US AIM-120 (AMRAAM) mid-range air-to-air missile (AAM) (Table 4), with rumours alleging that the TC-2’s seeker was derived from Motorola’s prototype seeker, which was originally intended for the AIM-120 but lost to the design of the Hughes company.

 

Table 4. Main specifications of Tien Chien-2 and early versions of AIM-120 missiles. Sources: AEEH, NCSIST, US Air Force, Designation-systems.

 

Interestingly, while the AIM-120 adopted a 7 inch diameter to pursue a very compact design, Taiwan chose a slightly enlarged 7.5 inch body, presumably to reduce difficulties in engineering and manufacturing. Other active-radar guidance mid-range AAMs developed in Asia, namely the Japanese AAM-4 and the Chinese PL-12/15, inherited the 8 inch (203 mm) diameter body from the previous generation of radar-guided AAMs (AIM-7 Sparrow).

The ground-launched TC-2 has an effective range of around 15 km (though this figure may be somewhat conservative).^[5] Thanks to its folding wings, it can be compactly stored in dual-missile launch canisters, which markedly simplifies the missile’s handling and reloading process (Figure 4). The adoption of folding wings also means that the missile could share the same production line with the shipborne TC-2N.^[6] On the other hand, the folding wings make the missile incompatible with the air-launched TC-2, though in practice this is not a great concern because the number of air-launched TC-2 is currently insufficient for the F-CK-1 fleet.^[7] However, if the air-launched variant receives additional orders, another type of ground-launched TC-2 launchers compatible with air-launched rounds might become more likely.^[8]

 

Figure 4. Top Left: Wings of a TC-2 being deployed immediately after leaving its transport and launch canister. Top right: Dual-missile canisters simplifies the handling and loading process of the ground-launched TC-2. Bottom: SAM systems emphasizing on compatibility with air-launched variants require more steps for loading, such as unboxing, loading and installation of wings. Images: Youth Daily, MNA, Estado Mayor Defensa

 

In the 2010s, the NCSIST also incorporated the T-92 40mm automatic anti-aircraft gun (Figure 5), built by the Armaments Bureau of the armed forces, into the ground-launched TC-2 system to form a missile-gun air defence complex. The T-92 has a rate of fire of 300 rounds per minute and an effective range of up to 4 km.

 

Figure 5. The NCSIST proposed to integrate the T-92 40 mm anti-aircraft gun with the ground-launched TC-2. Source: NCSIST

 

The ground-launched TC-2 was first put into the 2019 defence budget (Table 1). The 438 million USD procurement included a total of six Bee Eye radars and six radar command and control vehicles, 29 missile launch vehicles, support vehicles and 246 ground-launched TC-2 missiles. The 40 mm automatic anti-aircraft gun was excluded from the procurement plan, possibly due to the following factors:

●    Budget constraints

●  Weak perceptions on emerging threats posed by cheap loitering munitions and One-Way-Attack drones

●   Lack of smart/programmable munitions that could boost interception rate. (However, the NCSIST claimed that the 40 mm gun could take down a subsonic cruise missile with six rounds.^[9]

 

3. Deployment of Bee Eye, Avenger, and ground-launched TC-2

The ROC Army’s short-range surface-to-air missiles (excluding man-portable and dual mount Stinger missiles) are primarily operated by the 21st, 58th, and 43rd Artillery Commands in northern, western, and southern Taiwan.^[10] While the 21st and 58th Commands have been operating the Avengers, the 43rd Command in southern Taiwan was still using the outdated US M48 Chaparral SAMs. Early reports indicated that the ground-launched TC-2s would replace the Chaparrals, suggesting that the 43rd Artillery Command would be the sole user of the ground-launched TC-2. However, the ground-launched TC-2s were eventually distributed to all three Artillery Commands. Following the retirement of the Chaparrals in 2025 and the transfer of some Avengers to the 43rd Artillery Command, the ROC Army has formed a short-range air defence network consisting of Bee Eye radars, Avengers and ground-launched TC-2s (Figure 6) across the main island of Taiwan.

 

Figure 6. Engagement flow chat of Avengers and ground-launched TC-2 missiles under the command of Bee Eye radars. Source: ROC Army Artillery Quarterly

 

According to Figure 6 above, the ground-launched TC-2 does not need to be launched after seeker lock-on, which indicates that the missile, same as its air- and sea- launched variants, relies on flight path correction commands before its active radar seeker locks on the target. This suggests that the ground-launched TC-2 receives mid-course flight correction commands generated by the command and control vehicle.^[11] Consequently, the command and control vehicles paired with the first batch of 17 Bee Eye radars, which were previously integrated only with the Avengers, might be unable to generate mid-course commands to the TC-2. However, the NCSIST, as the developer for both the missile and the radar, can easily integrate these two elements.

Thus, if taking into account the first batch Bee Eye radars procured for the main island, a maximum of 23 small and highly mobile low-altitude SAM teams could theoretically be formed during wartime (Figure 7). Each team would consist of one Bee Eye radar (including one command and control vehicle), one to two ground-launched TC-2 missile launch vehicles, and two to three Avengers.^[12]

 

Figure 7. Air defence formations emphasising on neutralizing incoming threats (left) and the protection of key targets and installations (right). With the introduction of the ground-launched TC-2, featuring non-infrared guidance and longer range, a layered defence network with greater resilience against countermeasures has been formed. Red circle: Ground-launched TC-2, Orange and yellow circles: Avenger and man-portable Stingers. Source: ROC Army Artillery Quarterly

 

4. Insufficiencies to counter emerging and disruptive threats

The ROC Army’s high-end interceptors (Stinger and ground-launched TC-2) can not only effectively engage cruise missiles, manned aircraft and relatively sophisticated drones, but also take down cheap One-Way-Attack drones and loitering munitions. However, the cost-effectiveness of doing the latter has become too low to maintain a sustainable and resilient defence.

As shown in Table 2, the procurement cost associated with each man-portable Stinger missile currently has inflated to over 800,000 USD, while the unit cost of a ground-launched TC-2, roughly around one million USD per missile,^[13] is relatively cheap in its own class. In comparison, a Shahed-type One-Way-Attack drone domestically produced in Russia or a Russian Lancet loitering munition costs only about 35,000 USD. These price tags suggest that an attacking side may be able to quickly deplete Taiwan’s valuable SAM stocks if it mimics Russia’s strategy of mass employment of cheap One-Way-Attack drones and loitering munitions during a cross-Strait war.

With the retirement of the vintage US M42 self-propelled anti-aircraft guns in the 1990s, the ROC Army no longer possesses dedicated gun-based air defence assets on Taiwan’s main island.^[14] Though various ROC Army vehicles are armed with 12.7 mm and 30 mm machine guns (Figure 8), their specifications and/or fire control systems are not optimized for countering the emerging and disruptive threats posed by One-Way-Attack drones and loitering munitions, which have seen widespread use during Russia’s war on Ukraine.

 

Figure 8. Left: Avenger has a 12.7 mm M2 machine gun as a secondary armament for self-defence and close-in anti-air engagement. Middle: The ROC Army’s Clouded Leopard infantry fighting vehicle is equipped with a US Bushmaster II 30 mm chain gun. Right: Many ROC Army vehicles are also equipped with M2 machine guns. Images: MNA, CNA, ROC Army

 

As demonstrated during the 2025 Israel-Iran war, when provided with timely radar intelligence, the armed helicopters (AH-64E, AH-1W and OH-58D) of the ROC Army Aviation and Special Forces Command could intercept One-Way-Attack drones and loitering munitions with their airborne machine guns. However, in the event of a high-intensity war, airspace over the Taiwan Strait would be significantly more dangerous than that around Israel, where Israeli manned aircraft could fly uncontested. If Taiwan’s armed forces cannot keep PLA early warning aircraft at a significant distance from the main island, ROC Army helicopters conducting drone hunting missions at low altitude will risk being shot down by long-range anti-air missiles.

Emerging, disruptive and asymmetrical aerial threats are a serious concern not only pertaining to the ROC Army. This topic will be discussed in detail in the coming articles.

 

Acknowledgement: the author would like to thank Matt (Twitter handle @Lorenzo65278848), a long-time OSINT researcher in the subject matter, for his valuable feedback and review.

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