STATUS: Active, Limited Service
MANUFACTURER(S): SOKO - Yugoslavia / Bosnia and Herzegovina
OPERATORS: Libya; Republika Srpska (Bosnia and Herzegovina); Yugoslavia; Zaire; Zambia
LENGTH: 35.60 feet (10.85 meters)
WIDTH: 34.61 feet (10.55 meters)
HEIGHT: 11.98 feet (3.65 meters)
WEIGHT (EMPTY): 14,330 pounds (6,500 kilograms)
WEIGHT (MTOW): 24,791 pounds (11,245 kilograms)
ENGINE: 1 x BMD (Rolls-Royce / Bristol Siddeley) Viper Mk 531 turbojet engine developing 2,990lb of thrust.
SPEED (MAX): 510 miles-per-hour (820 kilometers-per-hour; 443 knots)
RANGE: 944 miles (1,520 kilometers; 821 nautical miles)
CEILING: 39,370 feet (12,000 meters; 7.46 miles)
RATE-OF-CLIMB: 4,100 feet-per-minute (1,250 meters-per-minute)
Detailing the development and operational history of the SOKO J-21 Jastreb (Hawk) Light Attack / Advanced Trainer Aircraft.
Entry last updated on 8/7/2018.
Authored by Staff Writer. Content ©www.MilitaryFactory.com.
The SOKO J-21 "Jastreb" ("Hawk") of the former Yugoslavia was a further development of the original G-2 "Galeb" of 1961 (detailed elsewhere on this site). The two-seat Galeb stood as the country's first indigenously designed, developed and produced aircraft and fulfilled the roles of advanced jet trainer and light attack aircraft for the Yugoslav Air Force. Two hundred forty-eight of the type were completed from 1965 to 1983. The J-21 continued this line as a direct offshoot and was developed specifically as a one-seat light attack platform to which followed 121 of the type produced from 1967 to 1977. Once again, the Yugoslav Air Force became a primary operator.
While the G-2 was used to succeed the aging, outgoing line of American Lockheed T-33 Shooting Star trainers, the J-21 was selected to succeed the aging, outgoing line of American Republic F-84 Thunderjet fighter-bombers.
The Jastreb was given a more powerful engine fit which increased both performance and capabilities and this allowed extra hardpoints to be installed for even greater war loads. The internal structure of the aircraft was reinforced and support for JATO (Jet-Assisted Take-Off) was introduced allowing for better short-field operation (2 x solid-fueled rocket units of 1,000lb thrust each). 3 x 12.7mm Browning AN/M3 Heavy Machine Guns (HMGs) now took their place in the nose assembly, unlike the two guns featured in the G-2. Hardpoints numbered eight and supported rockets and conventional drop ordnance including napalm and cluster bombs.
Because of its origins in the G-2, the J-21 retained much of the former design's form and function. The fuselage was slim in profile and accommodated a single crewman under a lightly-framed canopy with decent vision. The aircraft was powered by a single turbojet engine buried within the slender fuselage and this installation was aspirated by a small pair of intakes mounted to the sides of the fuselage. The wing mainplanes were straight and clipped at their tips where tanks were affixed. The tail unit featured a single vertical fin and low-set horizontal planes. The undercarriage remained a tricycle arrangement, wholly retractable.
Power stemmed from a BMB (Rolls-Royce / Bristol Siddeley) Viper Mk 531 turbojet engine of nearly 3,000 lb of thrust. Performance specs included a maximum speed of 820 kmh, a cruising speed of 740 kmh, a range out to 1,520 kilometers and a service ceiling of 12,000 meters. Rate-of-climb was 4,100 feet-per-minute.
Original production models were simply designated J-21 and this design could double as a reconnaissance aircraft in addition to fulfilling the ground attack role. The J-21E became an export version of this mark. The RJ-21 followed as a more dedicated reconnaissance model and outfitted with applicable photo-reconnaissance (camera) equipment for the role. The RJ-21E was, in turn, the export version of this model. The NJ-21 was developed as a two-seat advanced jet trainer that retained some of the light attack functionality common to the J-21 line.
J-21s saw combat exposure in the First Congo War (1996-1997) and the Yugoslav Wars of the 1990s. Several Serbian J-21s were engaged and shot down by American Air Force Lockheed F-16 Fighting Falcons. Operators of the J-21 series went on to include the Libyan Air Force, Republika Srpska, Zaire and Zambia. Some examples fell into the hands of rebels of the Free Libyan Air Force during the 2011 Libyan Civil War.
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Our Data Modules allow for quick visual reference when comparing a single entry against contemporary designs. Areas covered include general ratings, speed assessments, and relative ranges based on distances between major cities.
Relative Maximum Speed Rating
This entry's maximum listed speed (510mph).
Graph average of 562.5 miles-per-hour.
Graph showcases the SOKO J-21 Jastreb (Hawk)'s operational range (on internal fuel) when compared to distances between major cities.
Useful in showcasing the era cross-over of particular aircraft/aerospace designs.
Unit Production Comparison
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units