page_title: CAC/PAC JF-17 Thunder
section_title: Flight testing and redesigning
hierarchical_section_title: CAC/PAC JF-17 Thunder / Development / Flight testing and redesigning
caption_attribution_description: English: A model of the JF-17 Thunder fighter aircraft on display at an exhibition. The model includes six air-to-air missiles mounted on the JF-17's wings, two SD-10 medium range missiles and four PL-5E-II short range missiles.
context_page_description: The PAC JF-17 Thunder, or CAC FC-1 Xiaolong, is a lightweight, single-engine, multi-role combat aircraft developed jointly by the Pakistan Aeronautical Complex and the Chengdu Aircraft Corporation of China. It was designed to replace the A-5C, F-7P/PG, Mirage III, and Mirage V combat aircraft in the Pakistan Air Force. The JF-17 can be used for multiple roles, including interception, ground attack, anti-ship, and aerial reconnaissance. Its designation "JF-17" by Pakistan is short for "Joint Fighter-17", while the designation and name "FC-1 Xiaolong" by China means "Fighter China-1 Fierce Dragon".
  The JF-17 can deploy diverse ordnance, including air-to-air and air-to-surface missiles, and a 23 mm GSh-23-2 twin-barrel autocannon. Powered by a Guizhou WS-13 or Klimov RD-93 afterburning turbofan, it has a top speed of Mach 1.6. The JF-17 is to become the backbone of the Pakistan Air Force, complementing the General Dynamics F-16 Fighting Falcon at half the cost. The PAF inducted its first JF-17 squadron in February 2010. In 2015 Pakistan produced 16 JF-17s.
context_section_description: The first prototype, PT-01, was rolled out on 31 May 2003 and transferred to the Chengdu Flight Test Centre to be prepared for its maiden flight. This was initially planned to take place in June, but was delayed due to concerns about the SARS outbreak. The designation Super-7 was replaced by "JF-17" (Joint Fighter-17) around this point. Low speed taxiing trials began at Wenjiang Airport, Chengdu, on 27 June 2003. The maiden flight was made in late August 2003; an official maiden flight of the prototype took place in early September. The prototype was marked with the new PAF designation JF-17. By March 2004, CAC had made around 20 test flights of the first prototype. On 7 April 2004, PAF test pilots Rashid Habib and Mohammad Ehsan ul-Haq flew PT-01 for the first time. The maiden flight of the third prototype, PT-03, took place on 9 April 2004. In March 2004, Pakistan was planning to induct around 200 aircraft.
  Following the third prototype, several design improvements were developed and incorporated into further aircraft. Because of excessive smoke emissions by the RD-93 engine, the air intakes were widened. Reported control problems found in testing resulted in alterations to the wing leading edge root extensions (LERX). The vertical tail fin was enlarged to house an expanded electronic warfare equipment bay in the tip. The redesigned aircraft had a slightly increased maximum take-off weight and incorporated an increased quantity of Chinese-sourced avionics; however PAF had selected Western avionics for their aircraft, postponing PAF deliveries from late 2005 until 2007. Pakistan evaluated British, French, and Italian avionics suites, the winner of which was expected to be finalised in 2006. PT-04, the fourth prototype and the first to incorporate the design changes, was rolled out in April 2006 and made its first flight on 28 April 2006.
  The modified air intakes replaced conventional intake ramps—whose function is to divert turbulent boundary layer airflow away from the inlet and prevent it entering the engine—with a diverterless supersonic inlet (DSI) design. The DSI uses a combination of forward-swept inlet cowls and a three-dimensional compression surface to divert the boundary layer airflow at high sub-sonic and supersonic speeds. According to Lockheed Martin, the DSI design prevents most of the boundary layer air from entering the engine at speeds up to two times the speed of sound, reduces weight by removing the need for complex mechanical intake mechanisms, and is stealthier than a conventional intake. In 1999, developmental work on the DSI with the aim of improving aircraft performance commenced. The JF-17 design was finalised in 2001. Multiple models underwent wind tunnel tests; it was found that the DSI reduced weight, cost, and complexity while improving performance.
  For the avionics and weapons qualification phase of the flight testing, PT-04 was fitted with a fourth-generation avionics suite that incorporates sensor fusion, an electronic warfare suite, enhanced man-machine interface, Digital Electronic Engine Control (DEEC) for the RD-93 turbofan engine, FBW flight controls, day/night precision surface attack capability, and multi-mode, pulse-Doppler radar for BVR air-to-air attack capability. The sixth prototype, PT-06, made its maiden flight on 10 September 2006. Following a competition in 2008, Martin-Baker was selected over a Chinese firm for the supply of fifty PK16LE ejection seats.
caption: Model Of JF-17 Thunder
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