User:Hj108/Sandbox/JF-17

Development
The JF-17 is being built by China's Chengdu Aircraft Industry Corporation (CAC) and Pakistan's Pakistan Aeronautical Complex. The project is expected to cost around US$500 million, divided equally between China and Pakistan. The project is supported by China National Aero-Technology Import & Export Corporation for the Chinese side. Each individual aircraft is expected to have a fly-away cost of around US$8-15 million. Initial development of JF-17 is believed to have been completed in a period of four years, although later improvements to the aircraft design did take up more time. Pakistan has announced that it has 150 aircraft on order, but this may well go up to 275. The JF-17 will replace Pakistan's MiG-21-derived Chengdu F-7, Nanchang A-5 and Dassault Mirage III/Mirage V aircraft currently in service. Azerbaijan and Zimbabwe have already placed orders and eight other countries have expressed interest in purchasing the JF-17 at a recent military exhibition in Pakistan, according to an official.

Origins
After a successful deal with China's Chengdu Aircraft Corporation (CAC) in the early 1980s resulting in the Chengdu F-7M, the United Kingdom offered a further upgrade to improve the performance of the F-7M by adopting either General Electric F404 or Pratt & Whitney PW 1120 turbofan engines. The radar options would include the Red Fox, a repackaged version of the Blue Fox radar used on Sea Harrier FRS Mk 1, and the Emerson AN/APG-69. Although radar tests were successful, the upgrade was rejected before any engine tests because both the radar and engine cost more than a new J-7 (2 million 1984 United States Dollars). The name Super-7, however, was retained to be used for FC-1/JF-17.

In 1986, Chengdu Aircraft Corporation signed an agreement with Grumman Aerospace to develop an upgraded Chengdu F-7P called "Saber II" for the Pakistan Air Force. Considered a replacement of the abandoned Super-7 project, F-7 was redesigned with side intakes replacing the nose intake. The resulting aircraft looked like a single-seat Guizhou JL-9/FTC-2000. The General Electric AN/APG-67 radar used on the F-20 Tigershark would have been adopted. The program was terminated in 1990 due to the Tiananmen Square protest of 1989.

CAC kept the program alive by providing low-level funding from its own resources. After U.S. military and economic sanctions imposed on Pakistan in 1990 prevented the delivery of advanced F-16 Fighting Falcons, Pakistan again became interested in the continued Super-7 project which eventually evolved into the FC-1/JF-17.

Test flights
The first prototype was rolled out on 31 May 2003, conducted its first taxi trials on 1 July and made its first flight on 25 August of the same year. The third prototype, PT-03, made its first flight in April 2004. It is believed that at some point during these initial test flights, the name Super-7 was replaced by the Chinese designation FC-1 (Fighter China-1) and the Pakistani designation JF-17 (Joint Fighter-17).

The PT-04 prototype of JF-17 successfully completed its first operational flight in Chengdu, China, on Wednesday 10 March 2006. On 28 April 2006, PT-04 made its first flight with fully operational avionics. This prototype of JF-17 is configured as a multi-role fighter-bomber, equipped with advanced avionics and capable of carrying multiple air-to-air and air-to-ground weapons. Pakistan received the first consignment of 2 aircraft on 23 March 2007. China was supposed to start official production in June 2007 while Pakistan Aeronautical Complex was planning to start manufacturing the JF-17 in 2008.

Evolution
The fourth prototype version was redesigned, with divertless supersonic intakes (DSI) being the most notable new feature; the DSI design diverts turbulent boundary layer airflow away from the engine inlet. The wing leading edge extensions (LEX) were enlarged to improve flying characteristics. An electronic warfare fairing was added to the tip of the vertical stabiliser. Two sensors were fitted to the base of the vertical stabiliser to detect approach of enemy missiles.

At the 2006 Zhuhai Airshow, China, a Unit Training Device (UTD) appearing identical to the earlier mock-up of the JF-17 was publicly displayed.

A dual-seat combat-capable training variant was initially scheduled to begin flight testing in 2006, however the current plans for this variant are unknown. It has been stated by some sources that work on this variant has not yet started because the priority of the Pakistan Air Force is to induct a large number of the single-seat variant to replace old aircraft.

Airframe
JF-17's airframe is constructed from aluminium alloys to keep both costs and weight down while providing high structural strength. High strength steel and titanium alloys are partially adopted in some critical areas. Plans are in place to reduce weight further by increasing the use of carbon composite materials in the airframe.

The mid-mounted wings are of cropped-delta planform, giving the aircraft good low speed handling characteristics while reducing drag for high speed flight. Near the wing root are strakes, also called leading edge root extensions. These generate a vortex which has the effect of providing more lift to the wing at high angles of attack encountered during combat maneuvers. The wings make use of slats and flaps to increase lift for carrying heavy loads during take off and land safely in as short a distance as possible. Air-launched weaponry, mission/avionics pods and droptanks carrying extra fuel can be mounted on the eight hardpoints underneath the wings and fuselage.

A conventional tri-plane empennage arrangement is incorporated, with all-moving stabilator tail-planes to give high maneuverability and control, especially at supersonic speed. A conventional single fin and rudder are present, with twin ventral fins underneath the rear of the fuselage.

The retractable landing gear is of tricycle arrangement, with a single steerable nosewheel under the cockpit between the air intakes and two main gear wheels mounted under the fuselage, between the wings.

Two bifurcated air inlets, one on either side of the fuselage behind and below the cockpit, provide the jet engine's air supply. The position and shape of the inlets is designed to give the required airflow to the jet engine during maneuvers involving high angles of attack.

Flight Control System
JF-17 has a composite flight control system (FCS), comprising of conventional controls with stability augmentation in the yaw and roll axis and a digital fly-by-wire (FBW) system in the pitch axis. The leading edge slats/flaps and trailing edge flaps are adjusted by the flight control system automatically during maneuvering to increase turning performance. Some sources state that the system will be upgraded to provide fly-by-wire flight control in the roll and yaw axis also.

Overview
The aircraft cockpit is covered by a transparent acrylic canopy designed to give the pilot a good all-round field of view. The pilot sits on a rocket boosted ejection seat which is zero-zero capable, meaning the pilot can safely eject even at zero speed and zero altitude.

The pilot uses a centre stick to control the aircraft in pitch and roll. Rudder pedals control the aircraft's yaw motion (see flight dynamics). A throttle stick to control the engine throttle setting is located to the left of the pilot.

The cockpit incorporates "hands on throttle and stick" (HOTAS) controls to allow operation of all essential aircraft systems, especially combat-related systems such as radar and weapons, without the pilot having to remove his hands from the controls.

Avionics
The software used in the avionics systems of JF-17 totals more than one million lines of instructions, incorporating the concept of open architecture. Rather than using the common Ada programming language, which is optimised for security, the JF-17 software is written using the more commonly used C++ programming language to better utilize the large number of civilian software programmers available. The avionics of JF-17 prototypes used the Motorola 88000 microprocessor originally, but can be changed to other types of the same class. The fourth prototype of JF-17, PT-04, had many more advanced avionics features than its predecessors; these are included on the production version of the aircraft.

JF-17 uses a glass cockpit incorporating an Electronic Flight Instrument System (EFIS) and related Head-Up Display (HUD).

The EFIS is made up of three 8 inch by 12 inch multi-function displays (MFD) arranged side by side, with the centre display slightly lower down than the others. Each display has a portrait orientation (height greater than width) and each is a "smart" display, meaning they can be configured to show any of the available information.

The wide-angle holographic smart HUD has a minimum total field of view of 25 degrees. A separate monochrome up-front control panel (UFCP) is located between the HUD and the centre display.

The People's Liberation Army Air Force (PLAAF) experienced problems with the HUDs of its Russian designed combat aircraft, these tended to fog up due to deployment in humid sub-tropical and tropical zones. The HUD system fitted to JF-17 was developed to ensure this problem would not occur when deployed in any environment.

Western HUDs can be incorporated directly onto the aircraft, if desired by the user, with little effort due to the modular avionics design and the adoption of the MIL-STD-1553B databus architecture.

Normally radar information is displayed on the head-down multi-function displays, but JF-17 can also project radar images onto the HUD. This enables the pilot to keep his eyes focused at infinity so that he can simultaneously view radar information and monitor the airspace around him, without having to re-focus his eyes. Monochrome images from electro-optical navigation/targeting pods carried by JF-17 can also be projected onto the HUD.

It is known that a helmet-mounted display (HMD) (or helmet-mounted sight) will be installed on JF-17, although the exact type is yet to be confirmed. This system assists in targeting enemy aircraft by projecting targeting information onto the pilot's visor and tracking the movements of his head/eyes.

Communication
JF-17 is equipped with two communication radios, one of them having capacity for data linking. The data link can be used to exchange data with ground control centres, AWACS/AEW aircraft and other combat aircraft also equipped with data links.

The ability to data link with other "nodes" such as aircraft and ground stations allows JF-17 to become part of a network, improving the situational awareness of the pilot as well as other entities in the network (see network-centric warfare).

Self-protection systems
JF-17 is fitted with a radar warning receiver (RWR) that gives data to the pilot on direction and proximity of enemy radars, as well as an onboard electronic counter-measures (ECM) suite that interferes with these radars to help stop them targeting the aircraft. These systems can be enhanced by the addition of externally-mounted avionics pods: They also allow the aircraft to take on the roles of aerial reconnaissance and suppression (or destruction) of enemy air defence (SEAD) when armed with the appropriate weaponry.
 * BM/KG300G self protection jamming (ECM) pod
 * KZ900 electronic reconnaissance (SIGINT) pod

A missile approach warning (MAW) system uses several optical sensors mounted on the airframe that detect the rocket motors of missiles. Data collected by the MAW system, such as direction of inbound missiles and the time to impact (TTI), is shown on the cockpit displays and HUD to warn the pilot.

A countermeasure dispensing system releases decoy flares and chaff to help the aircraft evade enemy missiles and radars trying to track/destroy the aircraft.

Radar
It has been disclosed by PAF Air Chief Marshal Tanvir Mahmood Ahmed that Pakistan's JF-17s are equipped with the KLJ-7 radar. This is a pulse doppler fire-control radar developed by China's Nanjing Research Institute of Electronic Technology (NRIET). Its multiple modes mean that it can engage targets in the air, on the ground or out at sea. Using the track-while-scan (TWS) mode, enemy aircraft can be engaged at beyond visual range (BVR) while the radar continues scanning for new threats. Close-in aerial combat and ground surveillance modes are also available.

This radar can reportedly manage up to 40 targets, monitor up to 10 of them in track-while-scan (TWS) mode and simultaneously fire on two BVR targets. The detection range for targets with a radar-cross section of up to 3 m2 is stated to be 120 km, or 50 km in look-down mode, while surface sea targets can be detected at up to 135 km. Target data is displayed on the multi-function display screens in the cockpit.

During the early prototype stage a number of radar systems were tested for both production and possible export versions. A number of other radars have also been considered for export versions of the aircraft, one of these is the Italian FIAR Grifo S7, which was tailored to meet the PAF's initial requirements of the Super-7.

Weaponry
JF-17 can be armed with a total of 3,629 kg (8,000 lb) of air-to-air and air-to-ground weaponry mounted externally on the aircraft's eight hardpoints. One hardpoint is located under the fuselage between the main landing gear, two underneath each wing and one on each wing-tip. The wing-tip hardpoints are limited to carrying air-to-air missiles, although the rest can carry most types of weaponry. The under-fuselage and inboard under-wing hardpoints can also carry droptanks containing extra fuel (see Propulsion and fuel system). The aircraft's internal armament comprises of one GSh-23-2 twin-barrel 23mm cannon mounted under the port side air intake, which can be replaced with a GSh-30-2 30mm twin-barrel cannon.

Being primarily an export-orientated fighter, JF-17's tactical/mission avionics, i.e. weaponry and sensor avionics, support the MIL-STD-1760 data bus so that Western systems can easily be integrated with the aircraft. This allows JF-17 to effectively use Western as well as Chinese sensors and weapon systems such as radars, electronic warfare suites, missiles and bombs.

Advanced beyond visual range (BVR) air-to-air missiles such as the Chinese PL-12/SD-10, as well as other short range close-combat air-to-air missiles such as the Chinese PL-9 and the South African A-darter can be deployed.

Air-to-ground weapons such as unguided rockets, unguided gravity bombs and precision-guided munitions (PGM) such as satellite guided bombs can also be utilised.

For infra-red or laser-guided munitions, electro-optical targeting pods must be carried externally, such as the Chinese Blue Sky navigation/attack pod or the FILAT (Forward-looking Infra-red Laser Attack Targeting) pod. These pods enable JF-17 to attack targets in any weather during day or night.

Certain types of weapons, such as the Russian KAB series of bombs, need special adapter rails to be fitted to the aircraft's hardpoints.

Propulsion and fuel system
The JF-17 is powered by a single Russian Klimov RD-93 turbofan engine. This engine is a variant of the RD-33 engine used on the Mig-29 combat aircraft. The turbofan engine gives more thrust and significantly lower specific fuel consumption than the turbojet engines fitted to older combat aircraft being replaced by JF-17. The engine's air supply is provided by two bifurcated air inlets, their design being optimised to provide ample airflow to the engine even at high angles of attack encountered during violent combat maneuvers.

The advantages of using only one engine are that both maintenance time and cost are significantly lower than twin-engined fighters. The aircraft's small size and low weight gives a thrust-to-weight ratio of 0.99, comparable to many of its contemporaries such as the Dassault Mirage 2000.

After Indian protests, Russia and China had signed an end-user certificate for the RD-93 engines preventing China from exporting the JF-17 to Pakistan. In 2007 however, the President of Russia, Vladimir Putin made a surprise move and intervened, allowing re-export of the engines to Pakistan and six other countries. Following this the former Russian Prime Minister Mikhail Fradkov visited Pakistan to boost relations between the two countries.

JF-17's fuel system comprises of internal fuel tanks located in the wings and fuselage. These are refuelled through a single point pressure refuelling system (see turbine fuel systems) and can hold a maximum of 5,130 lb of fuel. Internal fuel storage can be supplemented by external fuel tanks. One 800 litre droptank can be fitted to the aircraft's centerline hardpoint and two 800 litre or 1100 litre droptanks can be fitted to the wings, each mounted on the two inboard under-wing hardpoints.

The fuel system is also compatible with aerial refuelling. When fitted with its extendable refuelling probe the aircraft can take on fuel from a tanker aircraft, increasing its range and loitering time significantly. Apart from the first 12 aircraft, all production JF-17s are expected to be fitted with extendable refuelling probes.

Variants

 * PT-01, PT-02, PT-03 - single-seat initial prototype variant
 * PT-04, PT-05 - single-seat final prototype variant, based on PT-03 but redesigned with larger leading edge root extensions, electronic warfare fairing fitted to vertical stabiliser, divertless supersonic intakes, etc. (see JF-17 evolution)
 * JF-17 / FC-1 - production single-seat variant, based on PT-04 redesign