In August 1964 the USAF took its first delivery of F-5As and immediately decided to send a few machines to the combat zone in order to test their capabilities. The so-called 'Skoshi Tiger' program was organized in October 1965, coinciding with the arrival of 12 F-5As, partially modified for war purposes and furnished with 'proboscis' equipment for refueling in flight. The fighter-bombers operated at first with the 4503rd TFW, and in the course of 2,500 hours of tactical support and reconnaissance missions gained experience that proved extremely valuable for launching the next, more powerful F-5E version, which took the name Tiger II in recognition of the aircraft's contribution to the Skoshi Tiger operation. The 12 F-5As of the 4503rd TFW, together with six new machines, were handed over to the 10th Fighter Command Squadron, attached to the 3rd TFW at Bien Hoa, and in 1967 the USAF delivered them to the VNAF. The F-5s were the first and only jet aircraft belonging to the newly formed South Vietnamese Air Force, which later received a number of F-5Es, used in action until the final collapse. Many of these F-5Es were captured by the North Vietnamese in perfect working order.
Planned at the start of 1955, the Northrop F-5 has become one of the most popular tactical fighters of the 1980s. Designed primarily for export, the aircraft's success is mainly due to its simplicity, lightness of weight and low cost, which, united with excellent performance and good armament, make it a worthy rival of bigger, stronger and more sophisticated planes. The F-5 prototype flew on July 31, 1959, and production was soon in full swing. About 1,300 of the early A and B variants (single - and two-seaters respectively, first flights July 31, 1963 and February 24, 1964) were built and sold to some twenty countries. Toward the end of the 1960s Northrop brought out the improved and more powerful F-5E Tiger (first flight August 1 1, 1972), which sold as successfully as its predecessors. The F-5As went into service with the USAF in August 1964, and in October 1965 a few machines were sent experimentally to Vietnam.
US Army Northrop N-156F
The Northrop N-156F light strike fighter prototype was one of three jet-powered, fixed-wing attack aircraft selected by the Army in 1961 for competitive evaluation in the forward air control (FAC), tactical reconnaissance, and ground attack roles. The N-156F was chosen for testing primarily because of its relatively simple design, impressive load-carrying capacity, and ability to operate from unimproved forward airfields.
Northrop had begun development of the N-156 family of low cost, lightweight supersonic aircraft in 1956, with the first design being that of the N-156F single-seat fighter version. Much to Northrop's chagrin the Air Force showed no real interest in the N-156F, though in June 1956 the service's Air Training Command did adopt a two-seat trainer variant as the T-38 Talon. In the spring of 1958 the Department of Defense renewed Northrop's hopes for the fighter version by directing the USAF to procure three N-156F prototypes for engineering and operational evaluation. The first of these aircraft (serial 59-4987) made its initial flight in July 1959, less than four months after the maiden flight of the first T-38. The Air Force's attitude towards the N-156F did not change appreciably despite the aircraft's excellent showing in the evaluations, however, and work on the number three prototype was halted prior to completion because the USAF did not feel that the remaining tests required a third aircraft. At the end of the test period the Air Force announced that it would not procure the N-156F, and Northrop was forced to temporarily suspend work on the fighter version. The company thus viewed the Army's 1961 decision to evaluate the N-156F as a possible reprieve and gladly supplied the first prototype machine and a complete ground support staff for the tests.
The N-156F was of fairly conventional layout with thin, slightly-swept, low-set wings, a fuselage characterized by a narrow area-rule section amidships, a one-piece 'all-moving' tail plane, a rather large vertical fin, and tricycle landing gear. The aircraft was built primarily of aluminium, and Northrop made considerable use of adhesive-bonded honeycomb as a stiffener in critical areas. The N-156F was powered by two afterburning General Electric J85 turbojets mounted side-by-side in the aft fuselage, and could be fitted with up to four 1,000 pound JATO (Jet-Assisted Take Off) bottles for operation from extremely short fields. More than a quarter of the aircraft's total fuselage area consisted of easily-removable access panels to simplify field maintenance, and both engines were attached to built-in overhead tracks for easy removal.
The Army's evaluation of the N-156F found it to be a well-built and capable aircraft, easy to maintain under field conditions and capable of carrying a significant offensive load while operating from the most rudimentary forward airstrips. These abilities were ultimately rendered meaningless, however, by the Army's decision to accede to Air Force pressure and abandon the quest for fixed-wing jet aircraft. The sole N-156F tested by the Army was susbsequently returned to Northrop, and was eventually converted into the prototype YF-5A Freedom Fighter.
Aircraft: Northrop F-5A