Paraguay eyes Taiwan's F-5 Tiger II fighters and AT-3 trainers to restore supersonic air defense.

Paraguay is evaluating the acquisition of Taiwan's recently retired F-5E/F Tiger II fighter jets and AIDC AT-3 Tzu Chung trainers to restore a supersonic combat capability absent for decades. The potential procurement aims to complement Paraguay's ongoing acquisition of subsonic Embraer A-29 Super Tucanos by introducing rapid Mach 1.63 interception speeds for tactical airspace control. However, integrating these older airframes presents significant operational challenges, requiring comprehensive radar modernization, sustained logistics pipelines, and a substantially higher flight-hour budget.

Paraguay is comparing the strategic value of Taiwan’s retired F-5E/F Tiger II fleet against its ongoing $101.6 million investment in Brazilian Embraer A-29 Super Tucanos. The procurement decision hinges on whether the capability of a Mach 1.63 interceptor justifies the estimated $5,000 hourly flight cost and the extensive avionics refurbishment required for 40-year-old airframes.

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Taiwan once had the world's largest F-5E/F fleet: the Taiwanese Air Force operated 336 Tiger IIs, including 242 F-5Es and 66 F-5Fs manufactured locally by AIDC under six Peace Tiger production batches between 1973 and 1986. (Picture source: Taiwanese MoD)

On August 16, 2026, the Asunción Journal revealed that Paraguay was evaluating the possible acquisition of Taiwan's retired F-5E/F Tiger II fighters and AIDC AT-3 Tzu Chung jet trainers, a package that could restore a supersonic combat capability absent for nearly four decades but would require the Paraguayan Air Force to support aircraft whose youngest Taiwanese-built examples are already 40 years old. Taiwan once operated 336 F-5E/Fs, the largest Tiger II inventory held by any country, and AIDC manufactured 308 of them locally under six Peace Tiger production batches, comprising 242 single-seat F-5Es and 66 two-seat F-5Fs between 1973 and 1986. Taiwan progressively removed the F-5 from front-line duties after introducing 150 F-16s, 60 Mirage 2000-5s and 130 F-CK-1s, then retired its remaining F-5Es in November 2023 and the last F-5Fs and RF-5Es in July 2025.

Paraguay is pursuing the proposal while completing a $101.6 million purchase of six Embraer A-29 Super Tucanos from Brazil, with four already operational and the final two scheduled for August 2026. The F-5 would offer a different capability from the A-29, which is primarily intended for surveillance, counter-narcotics, training, and light attack: at Mach 1.63, the F-5 surpasses Bolivia's K-8W jets, which are limited to Mach 0.75. The price of that speed is recurring expenditure. At $5,000 per F-5 flight hour compared with $1,000 to $1,200 for the A-29, Paraguay would spend the same $5 million on 1,000 F-5 hours that could finance 4,167 to 5,000 A-29 hours. The most consequential variable is not the F-5's nominal age but the condition of the individual aircraft Taiwan would transfer. Taiwan received 28 new F-5Es from the United States by May 1975 and then built the majority of its own fleet domestically, with production ending in 1986.

A Paraguayan F-5 could therefore have been manufactured anywhere from the mid-1970s to the final Peace Tiger batch, meaning an age spread of roughly 40 to more than 50 years in 2026. Airframe age alone does not determine remaining life because the decisive factors are accumulated flight hours, high-g maneuver cycles, landings, pressurization cycles, previous structural repairs, corrosion, storage conditions, and engine usage. Taiwan's fleet history confirms that these factors varied substantially between individual aircraft. Seven low-hour F-5Es were specifically selected for conversion into RF-5E Tigergazer reconnaissance aircraft, at a time when large numbers of Taiwanese F-5s had already been withdrawn, scrapped, or turned into decoys. By 2009, Taiwan retained only about 40 active aircraft and 90 to 100 in reserve. For Paraguay, a transfer of six aircraft with 1,500 to 2,000 hours of useful structural life remaining would be fundamentally different from six aircraft approaching major inspection thresholds. 

The baseline F-5E provides Paraguay with a genuine supersonic interception capability, but its original sensor and weapons architecture is limited by modern standards. The aircraft uses two General Electric J85-21 turbojets, each producing 3,600 lbf (16 kN) without afterburner and 5,000 lbf (22 kN) in afterburner, for a combined maximum afterburning thrust of 10,000 lbf (44 kN). Northrop enlarged the fuselage relative to the F-5A, increased internal fuel capacity and wing area, and fitted larger leading-edge extensions to improve maneuverability. Maximum speed is Mach 1.63, and the aircraft retains a compact size and low frontal area that were central to the original design. The early Emerson AN/APQ-153 radar was later replaced on some aircraft by the AN/APQ-159, which extends radar range to about 20 nautical miles, or 37 km. For its part, the two-seat F-5F originally used the AN/APQ-157 with a range of about 10 nautical miles, or 19 km.

The F-5E also carries two M39 20 mm cannons in the nose, while the F-5F's approximately three-foot-longer nose accommodates the second cockpit and reduces gun armament to one M39. These figures define the central limitation of a baseline Tiger II in 2026: Mach 1.63 allows it to reach an intruder quickly, but a radar with a 37 km class range does not provide the detection depth, track management, or engagement envelope associated with later fighter radars. Paraguay's effective capability would therefore depend on whether the aircraft carry AN/APQ-153 or AN/APQ-159 radars, what air-to-air missiles are available, whether radar-warning receivers are installed, and whether the fighters can exchange target information with Paraguayan ground radars. Taiwan itself examined that problem through the Tiger 2000/2001 program, but never converted its operational fleet.

The prototype first flew on July 24, 2002, and was intended to replace the F-5's legacy radar with the GD-53 used by the F-CK-1 Indigenous Defense Fighter and integrate a TC-2 beyond-visual-range missile on the centerline station. The Taiwanese Air Force did not proceed with fleet-wide conversion, leaving Taiwan's operational F-5s below the modernization level reached by Singapore and Brazil. Singapore converted its aircraft into F-5S/Ts with the FIAR Grifo-F X-band multimode radar, beyond-visual-range missile capability, MIL-STD-1553R databus, two multifunction displays, HOTAS, Litton LN-93 inertial navigation, and a new head-up display and weapons delivery system. The program ran from March 1996 to 2001 and cost about SGD 6 million per aircraft. In contrast, Brazil's modernization was broader and more expensive.

A $230 million program covered 46 F-5E/Fs, equal to $5 million per aircraft if divided evenly, and introduced Grifo-F radar, new electronic warfare equipment, INS/GPS, HOTAS, LCD displays, helmet-mounted displays, radar-warning receivers, encrypted communications, and onboard oxygen generation. Brazil also integrated Derby beyond-visual-range missiles and Python IV short-range missiles and connected the F-5EM fleet to R-99 airborne early-warning aircraft and ground stations. Paraguay would therefore need to distinguish clearly between acquiring Taiwanese F-5 airframes and acquiring a fighter capability comparable with Brazil's F-5EM. The latter requires a new radar, integrated missiles, digital cockpit architecture, electronic protection and secure communications, not simply refurbishment. Brazil also provides a useful cost benchmark because its experience separates the low purchase price of used F-5s from the much higher cost of returning them to a modern operational standard.

In 2009, Brazil bought eight F-5Es and three F-5Fs from Jordan for $21 million, or $1.91 million per aircraft. On April 14, 2011, it then signed a $153 million contract to modernize those aircraft and provide another simulator. The modernization contract was therefore 7.3 times the value paid for the 11 aircraft themselves. That relationship is more relevant to Paraguay than the headline price Taiwan might charge for retired aircraft. A transferred F-5 could require structural inspection, engine overhaul, corrosion treatment, replacement wiring, landing gear servicing, ejection seat work, radar refurbishment, communication equipment, radar-warning receivers, navigation systems, and weapons integration before entering routine service. A squadron also requires items that are not visible in the aircraft purchase price: J85 spare engines, engine modules, hydraulic components, tires, brakes, avionics line-replaceable units, ground power equipment, maintenance stands, test benches, simulators, instructor conversion and weapons stocks.

If Paraguay wanted six operational F-5s (the same size as its A-29 fleet) while maintaining two additional airframes as maintenance reserve, an eight-aircraft transfer would still not guarantee six available jets unless the spare parts package and maintenance pipeline can support a 75% availability rate. A fleet of eight aircraft at 50% availability would provide only four usable fighters at any given time, regardless of how inexpensive the initial transfer had been. The operating-cost arithmetic is equally restrictive because pilot proficiency requires flight hours that cannot be eliminated without reducing readiness. Using the $5,000-per-hour figure, a fleet generating 500 F-5 hours per year would cost $2.5 million in direct flying costs; 1,000 hours would cost $5 million; 1,500 hours $7.5 million; and 2,000 hours $10 million.

A six-aircraft fleet flown for 150 hours per aircraft annually would total 900 hours and $4.5 million. At 200 hours per aircraft, it would reach 1,200 hours and $6 million. If Paraguay eventually operated eight F-5s at 150 hours each, the total would rise to 1,200 hours and the same $6 million; eight aircraft at 200 hours each would require 1,600 hours and $8 million. None of those figures includes simulator operations, weapons training, salaries, depot maintenance, overhaul, or infrastructure. The comparison with the A-29 is stark: $1 million purchases only 200 F-5 hours but 833 A-29 hours at $1,200 per hour or 1,000 hours at $1,000 per hour. Paraguay is therefore not choosing between two aircraft with similar cost structures. One F-5 hour consumes the budget of 4.17 to 5 A-29 hours.

If annual fighter funding were capped at $5 million in direct flying expenses, for instance, Paraguay could generate 1,000 F-5 hours, which would support six aircraft at 166.7 hours each, or eight aircraft at only 125 hours each. That is the level at which fleet size, pilot numbers, and annual proficiency requirements become inseparable budget questions. Taiwan's experience also shows why a complete logistics package would be more important to Paraguay than receiving the maximum possible number of airframes. Taiwan operated a total of 336 F-5E/Fs and built 308 of them domestically, giving it a pool of engines, components, tooling, and institutional knowledge developed over several decades. By 2009, however, the active force had fallen to about 40 aircraft, with 90 to 100 held in reserve and others already scrapped or used as decoys.

The remaining fleet continued primarily in training and reconnaissance rather than front-line air defense. Aging also affected safety. On March 22, 2021, two Taiwanese F-5Es collided during a training sortie, and both pilots were killed, the third Taiwanese F-5 accident within six months. Taiwan retired its remaining F-5Es in November 2023 and kept only F-5Fs and RF-5Es until July 2025, when three RF-5Es and two F-5Fs conducted the final flight from Hualien. For Paraguay, the decisive items in a Taiwanese transfer would therefore include spare J85 engines, engine hot sections, hydraulic actuators, wheels, brakes, landing-gear components, flight control components, radar units, electrical equipment, cockpit instruments, ground-support equipment and donor airframes for cannibalization.

A transfer of six fighters plus four non-flying donor aircraft and several spare engines could have greater long-term value than ten flyable fighters delivered without a deep spares inventory, as shown by India's Jaguar fleet. The final calculation is about the amount of air defense Paraguay can generate per unit of expenditure. Paraguay has already committed $101.6 million to six A-29s, equal to $16.93 million in total program expenditure per aircraft when divided evenly, and four Paraguayan A-29s participated in Salitre 2026 in Chile with a 27-person contingent. The A-29 provides large numbers of comparatively inexpensive hours for border patrol, counter-narcotics surveillance, training, and light attack, while the F-5 would provide something materially different: rapid interception.

Its Mach 1.63 maximum speed is 2.17 times the Mach 0.75 attributed to Bolivia's Sino-Pakistani K-8W. That speed difference matters when an aircraft must cover 100, 200, or 300 km from its base to identify an unknown contact, but speed alone does not produce a modern air defense system. Argentina's F-16s combine higher-end radar, missile, electronic, and communications capabilities that a baseline 1970s F-5E does not possess. Paraguay would therefore need to decide whether the objective is simply to restore a limited supersonic visual-intercept capability or to create a more complete fighter force like Brazil, with modern radar, beyond-visual-range missiles, secure communications, and electronic self-protection.

The AT-3 could reduce the transition gap from the A-29 to the F-5 by introducing pilots to jet operations before supersonic conversion, but it would also add a separate engine, maintenance system, spare-parts stock, and training pipeline. In budget terms, every $10 million assigned to direct flight operations would buy 2,000 F-5 hours versus 8,333 to 10,000 A-29 hours. Paraguay would therefore be paying four to five times more per flying hour to obtain supersonic interception, while also accepting the refurbishment and logistics burden of 40-to-50-year-old aircraft. Whether that trade is militarily sustainable will depend on the exact airframes selected, their remaining fatigue life, the radar and weapons configuration, the size of the Taiwanese spares package, and the number of annual F-5 hours Paraguay is prepared to finance.

Written by Jérôme Brahy

Jérôme Brahy is a defense analyst and documentalist at Army Recognition. He specializes in naval modernization, aviation, drones, armored vehicles, and artillery, with a focus on strategic developments in the United States, China, Ukraine, Russia, Türkiye, and Belgium. His analyses go beyond the facts, providing context, identifying key actors, and explaining why defense news matters on a global scale.

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