twin-barrel 23mm Gryazev-Shipunov GSh-23L cannon with up to 200 rounds. In addition, four hard points are installed beneath the wings, the inboard pair having a capacity while the outboard have a capacity; these can carry a variety of Western and Eastern European armaments and equipment; the inboard pylons are plumbed for 70 gallon external fuel tanks, a locally developed reconnaissance pod was also under development at one stage. The G-4 is powered by a single British-sources Rolls-Royce Viper turbojet engine. Since its introduction, the aircraft's performance has been considerably improved by the adoption of the more powerful Rolls-Royce Viper 632-46 engine. For further performance, attachment points for jet-assisted take-off (JATO) rockets are present underneath the fuselage. To shorten landing distances, a drogue parachute can be deployed. Direct access to the engine is achieved via the removal of the rear fuselage forward of the fin. Operational history During the early 1990s, Yugoslavia embarked upon an upgrade programme for its G-4 fleet. Reportedly, this programme primarily revolved around the integration of new air-to-air and air-to-ground missiles, as well as an improved aiming capability, adjustments to raise engine reliability, and enhanced electronics. The G-4 Super Galeb performed numerous combat missions during the Yugoslav Wars. In total, three G-4s were reportedly shot down, all pilots of which ejecting safely. As a result of the Yugoslav Wars, the nation of Yugoslavia broke up into multiple smaller nations; several of which possessed aircraft from the former republic's inventory. During the NATO bombing of Yugoslavia, seven G-4s of the Leteće zvezde aerobatics team were destroyed at Golubovci Air Base, heavily contributing to the team disbanding during 1999. Since then, a group of Serbian aviation enthusiasts have assembled a new display team, but have equipped it with older Soko G-2 Galebs that had been previously withdrawn during the 1980s. Since 2008, the Serbian Air Force, the largest operator of the type, has proposed a comprehensive upgrade of their remaining G-4Ms. Intended to be re-designated G4-MD, the envisioned upgrade programme, which largely revolves around new avionics for improved navigation, greater ease of control, and integrate new combat systems, is reportedly set to extend the type's service life through to the 2030s. Serbia has been able to acquire additional G-4s from other former Yugoslavian republics, often by bartering, to expand its operational fleet. Variants G-4: Advanced jet trainer and light ground-attack aircraft. G-4Š: Unarmed jet trainer. G-4T: Dedicated target tug