The First Soviet Supersonic Fighter
The MiG-19 was taken for its premier flight on 5 January 1954 by G. A. Sedov, now the chief constructor at the Mikoyan ОКБ. It is no secret that the transition to supersonic speed was lengthy, tricky, and bloody. Ivashchenko died in a MiG-17, and many pilots were lost in other OKBs and aircraft manufacturers all the world over.
Some pilots succeeded in reaching and even surpassing Mach 1 for a short while, but for the true supersonic effect one had to maintain that speed for a long time in level flight. The SM-2, the first prototype of the MiG-19, seemed to have all of the prerequisites for supersonic flight: a thin wing with a high sweep angle (57 degrees), a reduced master cross-section, and a pair of AM-5A engines, a new type of compact and efficient turbojet. But the problem proved to be far more intricate than expected. More than one person would have lost heart, but all concerned clenched their teeth and committed themselves deeply.
Work on the engine got under way when it was decided to add an afterburner to the axial flow AM-5A turbojet. Mikulin knew how to make a success of this afterburner with an efficient flame holder that did not reduce the gas rate of flow in the combustion chamber. The armorer N. I. Volkov moved two of the three cannons and their ammunition into the leading edge of the wing near the root. In this manner, empty space in the wing was filled and some much-sought-after room was made in the fuselage for new equipment.
For their part, A. G. Brunov, deputy chief constructor, and R. A. Belyakov, department manager, developed a new servodyne-powered flight control unit. The variable incidence stabilizer was replaced by a stabilator, a single pivoted tailplane (without elevator) for pitch control (also called a slab tailplane) All flight control systems were duplicated to guard against failure of the main unit, and the stabilator was fitted with a booster control and an artificial feel unit. (As explained by Bill Gunston in Jane’s Aerospace Dictionary, "In aircraft control system artificial feel can be explained by forces generated within system and fed to cockpit controls to oppose pilot demand. In fully powered or boosted system there would otherwise be no feedback and no ‘feel’ of how hard any surface was working.”) The engine flameout problems that occurred during cannon tests with the MiG-9 had not been forgotten, and everything was done to dodge the difficulty. The ejection procedures were also improved to protect the pilot at much higher speeds.
A lot of useful information was collected during the SM-2 flights. Unexpected spins occurred due to the blanketing effect of the wing on the stabilator at great angles of attack (AOA). The aircraft had to be returned to the wind tunnel, and tests there led engineers to move the stabilator from the top to the base of the fin. Moreover, the location of the wing fences was modified. This is how the SM-2 became the SM-9.
At this time the North American F-100 Super Sabre could not exceed Mach 1.09. From the start Sedov reached Mach 1.3 or 1,400 km/h (756 kt) in the MiG-19 and thereby beat—unofficially—the world speed record. But there remained many youthful inadequacies to cure. The stretch of the turbine blades at high rotation speeds ceased to be a problem once new heat-resistant steel was used to make the blades. The inadequate roll handling was improved by placing spoilers ahead of the ailerons. The longitudinal swings noticed at high speeds vanished thanks to the new artificial feel system. The pressure surges felt on the rudder pedals at transonic speed were remedied by initiating a vortex flow—or burbling—on the rear of the fuselage. All of this was done step by step.
Only fourteen months after the SM-9’s first flight, two production MiG-19s were delivered to a hghter regiment. The MiG-19 was mass – produced and operated in many countries.