The HAL HF-24 Marut ("Spirit of the Tempest") was an Indian jet fighter aircraft developed and manufactured by Hindustan Aeronautics Limited (HAL) during the 1960s and early 70s. The Marut was designed by the German aeronautical engineer Kurt Tank, with the Project Engineer being George William Benjamin. The aircraft was the first Indian-developed jet fighter and the first in Asia, outside the Soviet Union, to go beyond the test phase and into serial production and active service. On 17 June 1961, the type conducted its maiden flight; on 1 April 1967, the first production Marut was officially delivered to the IAF. While the Marut had been envisioned as a supersonic-capable interceptor aircraft, it would never manage to exceed Mach 1. This limitation was principally due to the engines used, which in turn had been limited by various political and economic factors; multiple attempts to develop improved engines or to source alternative powerplants were fruitless. The Marut's cost and lack of capability in comparison to contemporary aircraft were often criticised. Nevertheless, the Marut performed relatively well in combat, primarily as a fighter-bomber in the ground attack role. Most notably participating in the Battle of Longewala during the Indo-Pakistani War of 1971. A total of 147 Maruts were manufactured, with the Indian Air Force (IAF) being the sole operator. By 1982, the Marut was becoming increasingly obsolescent, and was gradually phased out during the late 1980s. During the 1950s, Hindustan Aircraft Limited (HAL) had developed and produced several types of trainer aircraft, such as the HAL HT-2. However, elements within the firm were eager to expand into the then-new realm of supersonic fighter aircraft. Around the same time, the Indian government was in the process of formulating a new Air Staff Requirement for a Mach 2-capable combat aircraft to equip the Indian Air Force (IAF). However, as HAL lacked the necessary experience in both developing and manufacturing frontline combat fighters, it was clear that external guidance would be invaluable; this assistance was embodied by Kurt Tank. In 1956, HAL formally began design work on the supersonic fighter project. The Indian government, led by Jawaharlal Nehru, authorised the development of the aircraft, stating that it would aid in the development of a modern aircraft industry in India. The first phase of the project sought to develop an airframe suitable for travelling at supersonic speeds, and able to effectively perform combat missions as a fighter aircraft, while the second phase sought to domestically design and produce an engine capable of propelling the aircraft. Early on, there was an explicit adherence to satisfying the IAF's requirements for a capable fighter bomber; attributes such as a twin-engine configuration and a speed of Mach 1.4 to 1.5 were quickly emphasised. During development, HAL designed and constructed a full-scale two-seat wooden glider to act as a flying demonstrator. Designated HAL X-241, this replicated production aircraft in terms of dimensions, control configuration, and aerofoil sections. The wheel brakes, air brakes, flaps, and retractable undercarriage were all actuated using compressed gas, with sufficient gas storage aboard for multiple actuations per flight. On 3 April 1959, the X-241 flew for the first time, after being towed into the air by a Douglas Dakota Mk.IV (BJ 449). A total of 86 flights were conducted prior to the X-241 sustaining considerable damage in a landing incident , when the nose undercarriage failed to extend. On 24 June 1961, the prototype Marut conducted its first powered flight. It was fitted with the same UK-manufactured Bristol Siddeley Orpheus 703 turbojets that were installed in the Folland Gnat airframes that were already being manufactured, under license, by HAL. While the Marut had been designed around significantly more powerful engines, the un-reheated Orpheus 703 was a viable powerplant for testing purposes. This meant that the Marut was barely capable of Mach 1, even though a top speed of Mach 2 had originally been considered necessary. Before suitable, afterburning engines had been obtained, the Indian Government decided to order 16 pre-production and 60 production Maruts, powered by the Orpheus 703. For more details of development, operational history and variants, click here.
