JF-17 Thunder Multirole Fighter [Thread 7]

[razgriz19]

Don't forget additional lift from bigger wings too

And drag. You can't just have one and not the other

 

[nang2]

Anything of interest said in there for some of us who cannot speak Chinese?

Thanks

the last sentence says it can carry anti-ship missiles.

 

[khanasifm]

the last sentence says it can carry anti-ship missiles.

Need detail which are not evident from video

 

[Thorough Pro]

Yes, but comparatively lift is way more than the drag, that is why all the planes fly

And drag. You can't just have one and not the other

 

[Dazzler]

B being stress and fatigue tested...

From Huitong..


This tandem-seat trainer version was developed at the request of Pakistani AF, which also pre-ordered the first prototype. JF-17B is believed to have been based on the JF-17 Block II configuration with a IFR probe and an LED probe light installed on the starboard side of the forward fuselage.

The aircraft features an enlarged and raised spine which creates additional space for flight instruments and fuel in order to compensate the space occupied by the rear cockpit. The aircraft also features a more swept vertical tailfin in order to reduce drag and to maintain the center of gravity.

A new LED landing light was installed above the front landing gear. A more powerful cockpit environmental control system has been installed as well to accommodate two pilots. More composite materials have been used in order to reduce the weight and to strengthen the structure. JF-17B is reportedly controlled by a new 3-axis digital FBW system replacing the old analog system.

The aircraft is equipped with the same KLJ-7 PD fire-control radar and retain the same BVR as well as precision air-to-ground strike capabilities as JF-17 Block II. As the result JF-17B represents a very attractive option to foreign customers with limited budget and resources.

Its length is 14.5m, height is 4.6m, TO weight is 9.4t, max external load is 4.6t. A model of the aircraft was first unveiled at the 2013 Paris Airshow by CATIC. The development started officially in 2014. The 01 prototype of JF-17B was constructed in December 2016 and conducted its first taxiing test on April 21, 2017. The JF-17B BC0001 prototype conducted its maiden flight on April 27, 2017.

 

[Cool_Soldier]

There were few reports about AESA Radar system such as KLJ A?
Any confirmation about it?

 

[Ultima Thule]

There were few reports about AESA Radar system such as KLJ A?
Any confirmation about it?

On JF-17B? i don't think so bro

 

[Bilal Khan (Quwa)]

There were few reports about AESA Radar system such as KLJ A?
Any confirmation about it?

The JF-17B was designed to have an AESA radar eventually, but not right away - it will be equipped like the Block-II initially.

 

[CriticalThought]

Yes, but comparatively lift is way more than the drag, that is why all the planes fly

Drag DOES NOT cause the aircraft to 'not fly'. Loss of airspeed does, which can happen due to many causes.

 

[khanasifm]

So just 400 kg weight gain for additional seat and fuel instead of say 800-1000kg rest addressed due to fly by wire and composites pretty good also max takeoff weight also gone up so looks like now it's 13 ton class vs 11 ton max takeoff

 

[monitor]

L-15B attack variant IFF antenna, which is similar to F-16.

Who copied who ?

JF-17 Thunder – a road to operational maturity

Date: Travanj 27, 2017Author: rocket pilot 0 Komentari


Airshow China 2012, Feature photo: Peng Chen

Two years of presence on the world’s biggest air shows brought it a reputation of a well balanced aircraft. It’s performance are solid. Not in the top five but within third generation standards. Sensors and weapons are too and it’s two to three times cheaper than the closest competition, the US F-16 Fighting Falcon and the Russian MiG-29. But, did the JF-17 reach the level of operational maturity to be entrusted with the defense of the country or everything just ends with a nice air show flying?

When the JF-17 debuted in front of the world aviation audience at Farnborough air show in 2010, Pakistan Air Force had only one squadron with 20 aircraft. Conversion training syllabus has just been approved and the only weapons the aircraft could carry were the general purpose bombs and the short range PL-5EII missiles. But, the things have changed now. “Now we have two JF-17 squadrons: the 16th squadron, the ‘Black Panthers’ and the 26th squadron, the ‘Black Spiders’. The 16th is a fully operational squadron while the 26th has two roles: conversion and operational training. We are about to raise the third squadron but we still didn’t decide which one will that be. We have around 40 JF-17’s flying at the moment with a last few from Block 1 in the final stages of the assembly”, said Air Commodore Khalid Mehmood, the JF-17 program deputy director.

Pakistan’s Pride

In Pakistan, the JF-17 is a matter of national pride. When the program started, in the late 90s of the last century, Pakistan was under sanctions for of its nuclear weapons development program. Its economy was in dire straits and its air force without the spare parts for the F-16s, the only modern fighters in its inventory. At the same time it´s biggest rival India started recording unprecedented levels of economic growth and initiated one of the most comprehensive air force modernization programs in its history. Abandoned by the west, Pakistan couldn’t do nothing else but turn to China. Even thou at that time China still didn’t have modern indigenous fighter design its Chengdu Aircraft Industry Corporation (CAC) had something that could be useful to Pakistan Air Force. It was the FC-1 Xiaolong, a light fighter in concept very similar to the Northrop’s F-5G Tiger Shark. Preoccupied with the development of the more advanced J-10 Chinese Air Force wasn’t showing a particular interest for it so CAC was looking for a new partner. For Pakistan Air Force it was the opportunity not to be missed and very soon deal for co-development was signed. It was a good deal because for only half a billion US dollars (an equivalent to a squadron of modern western fourth generation fighters) Pakistan Air Force not only got a 50% share in the production of components and the complete final assembly line but it got a chance to fully adapt the aircraft to its requirements. “Our pilots and engineers are responsible for 90% of the JF-17’s system architecture and cockpit design. Their knowledge and experience was used in the design of the HOTAS functionalities, switching layout and displays layout. They where the ones who decided where a particular information will be presented on the displays and how will the display setup change according to the mission scenario”, said Air Commodore Khalid.

Advanced Man-Machine Interface

Although the Pakistan Air Force became one of the first foreign users of the F-16, the JF-17’s cockpit much more resembles one other aircraft – the Swedish Gripen. Namely, at one point Pakistan Air Force seriously considered buying the Gripen so a team of pilots and engineers was sent to Sweden to thoroughly test it. “The Gripen was a great inspiration when we started with the development of the JF-17”, said Group Captain Chaudhry Ahsan Rafiq from the JF-17 program office. Unsurprisingly, three big 8×6 inch color multifunction displays dominate its cockpit and a small number of switches implies there is a solid level of automation in the systems as well. The simbology itself, however, looks like it is coming from the F-16. “Why change something if it works”, said one of the Pakistan Air Force pilots who wanted to stay anonymous for protocolary reasons at the Airshow China. Although he was obviously coming from the F-16 community keeping the same simbology across the fighter fleet significantly eases and thus lowers the cost of training be it for young pilots coming from the academy or more experienced ones going trough the conversion.

Hybrid Flight Control System

In addition to the advanced men-machine interface another feature that separates the JF-17 from second generation fighters is the hybrid flight control system. Namely, the mechanical flight control systems found in second generation fighters, the ones the JF-17 was made to replace, don’t offer any kind of protections so pilots are reluctant to use their full aerodynamic potential by flying close to the edge of the envelope. Modern, fully electronic flight control systems offer all kind of protections but they don’t come cheap or at least they didn’t when the development of the JF-17 started. “The cost control was a priority from the beginning so a much simpler and thus cheaper hybrid flight control system was chosen for the JF-17. In comparison to modern electronic flight control systems it has only one electronic channel, one for pitch. The other two, for bank and yaw are mechanical. It was a minimum requirement to have the angle of attack and the G forces, the two most important flight parameters in maneuvering flight, under the control of a computer. However, technology advanced so now we can offer a fully digital flight control system which is only 10% more expensive than the current hybrid one. It’s on the drawing board at the moment but if some prospective customer wants it we can have it certified in two years time”, said Zhu Zeng, a CAC representative at the Airshow China. Nevertheless, as simple as it is, the hybrid flight control system is still a huge improvement over the mechanical systems. “By knowing the computer will not allow me to exceed the angle of attack and G force limits, 26 degrees or 8 Gs, which ever comes first, I can fly this aircraft much more aggressively”, said one of the Pakistan Air Force JF-17 pilots who just converted from the F-7 (Chinese copy of the venerable MiG-21).

A proven engine

Considering a long time relationship between Russian and Chinese aviation industry it is no surprise that the engine chosen for the JF-17 is the Russian Klimov RD-93. As an adaptation of the RD-33 turbofan from the MiG-29 it lags behind its western counterparts in terms of fuel consumption and time between overhaul (TBO) but its Soviet origin gives it an excellent reputation when it comes to “less than ideal” infrastructure of the Third World. “We have flown 7000 hours with the engine and we didn’t have any problems. It’s a very robust engine. It doesn’t have a FADEC but it has a form of electronic control so it’s completely care free in operation”, said Air Commodore Khalid. A further testament to its reliability comes from the “hot & high” trials conducted from an airfield at 7000 ft above mean sea level and under ambient temperatures of between 25 and 30 degrees C. According to a report the JF-17 took off and landed in combat configurations under such conditions.

To further reduce the weight and complexity of the JF-17 Chinese engineers also found a way to match the RD-93 engine with a novel inlet design called the Divertless Supersonic Inlet (DSI). In comparison to a “traditional” inlet design the DSI doesn’t have any moving parts so it’s very light and easy to maintain. For it’s primary function, which is to slow down the airstream, it solely relies on the aerodynamic hump placed at its mouth. Conveniently, this hump also hides the face of the engines‘s compressor thereby further reducing already low radar signature of the JF-17 (low radar signature is an inherent feature of a light fighter).

Weapons integration

In comparison to the Indian Tejas the JF-17 wasn’t conceived with the same level of self reliance in mind. But, when it comes to the integration of new weapons it provides Pakistan Air Force with lots of flexibility. “We have a complete source code for the flight control system and for the weapons computer. We can buy any weapon on the free market and integrate it on the JF-17 on our own and in country. We have a team of flight test engineers and pilots who form the flight test group as a separate unit so the whole process is done by Pakistan Air Force”, said Air Commodore Khalid.

Further adding to the JF-17‘s flexibility is the 1760 interface on its hard-points. Since it’s a digital interface the 1760 eliminates the need to rewire the aircraft every time a new weapon is added.Since the short range PL-5E-II missile also has 1760 interface Air Commodore Khalid was asked if a helmet mounted sight (HMS) will become a part of any future block upgrade. “We will go directly to Helmet Mounted Display (HMD) technology. We don’t have the definite time when we will end the process of integration but we are in the integration phase and we are doing it on the Block 1 aircraft”, he said.

The sensors

The JF-17’s primary sensor for air-to-air combat is the KLJ-7 radar developed by the Nanjing Research Institute of Electronic Technology (NRIET). Reportedly, it is a scaled down version of the KLJ-10 radar developed for the J-10 with a range that’s supposedly matched with the range of the SD-10 radar guided BVR missile of which two are carried in standard air-to-air configuration. “We have the capability to carry four but we decided we don’t want to. The JF-17 is a small aircraft and we decided we need fuel more than the extra two missiles”, said Air Commodore Khalid. In addition to two SD-10 missiles on outer-wing stations standard air-to-air configuration implies two PL-5EII missiles on wing-tip stations and two or three external fuel tanks (1000 liter on inner-wing stations and 800 liter on under-belly station).

For self defense the JF-17 is equipped with a fully integrated electronic warfare (EW) system which, according to Group Captain Ahsan is not of Chinese origin. The system comes with a full ground support equipment which is a key for autonomous development of threat libraries and jamming techniques. It has a central control unit and four major subsystems: Radar Warning Receiver (RWR), Missile Approach Warning System (MAWS), flare and chaff dispenser and a jammer. “Since it is a small aircraft the jammer will have to be carried externally”, said Group Captain Ahsan. At the Airshow China the JF-17 was presented with the Chinese KG-300G jamming pod but it is unconfirmed if this is the pod actually used by Pakistan Air Force. According to manufacturers brochure the pod is highly adaptive and can be integrated with other avionics such as RWR and MAWS.

For air-to-ground combat the JF-17‘s primary sensor is the INS/GPS platform allowing for standard CCRP/CCIP sight modes, a key prerequisite for accurate delivery of general porpoise bombs. However, for more complex scenarios the Precision Guided Munitions (PGM) will be carried. “At the moment we are using a combination of Western and Chinese types of PGMs but for targeting we are still relying on a buddy lasing”, said Air commodore Khalid.

At the Airshow China the JF-17 was presented with the LT-2 laser guided bomb and several LS-6 family of long range GPS and laser/GPS guided bombs developed by the Luoyang Opto-electro Technology Development Centre (LOEC). Both come in the kit form consisting of a tail unit with a guidance module and a mid body strap-on section with foldable wings for additional range, effectively converting the general purpose bombs into a precision guided munitions. According to company representatives the route of the bomb can be pre-programmed so attack could be executed from a less defended direction. However, the true value of this bombs comes from the fact they are using a Chinese satellite navigation system, the Beidou. At the moment the Beidou covers only China and neighboring countries but from 2020, when the entire constellation of more than 30 satellites will be in orbit, the coverage will be global giving China and its allies total independence from the US system.

Two C-802A missiles are normally carried on inner-wing stations when the aircraft is in the anti-shipping role or the two Brazilian MAR-1 missiles when it is in the Suppression of Enemy Air Defenses (SEAD) role. At the Airshow China the JF-17 was also presented with the CM-400AKG land attack missile but it is unknown if the missile is actually operational with the Pakistan Air Force.

Networking

A light fighter doesn’t have the performance nor it carries enough weapons to be an air superiority fighter. But, when networked and employed in big numbers it will give any enemy a run for its money. Swedish Air Force was aware of that when it started developing the Gripen and Pakistan Air Force is aware of it now with the JF-17. “Data link is a national matter. We don’t want somebody else reading our information so we developed our own system for the JF-17. We are now working to connect it with the Link-16 system we have on the AWACS and the F-16 fleets”, said Group Captain Ahsan. Reportedly, the idea is to use strategically dispersed ground relay stations that will translate and then retransmit signals between different systems. However, the current status of the program is unknown at this time.

Operational employment

Today the 16th squadron is the only operational JF-17 unit. According to Air Commodore Khalid it’s fully qualified for Quick Reaction Alert (QRA) duty not only in peace but in war time as well. “We have a national mod V Identification Friend or Foe (IFF) system so we can go straight up and shoot at the enemy”, he said. Reportedly, the JF-17 didn’t see any combat in the Federal Administered Tribal Areas in the north of Pakistan but it did saw a lot of exercises, national as well as international ones with Chinese Air Force. “We have a very good experience with Chinese. We trained in all kind of scenarios with their Su-27’s, including air combat one vs. one, two vs. two and many vs. many with all the capabilities the Su-27 has and all we have so it was very good”, said Air Commodore Khalid.

The Two-seater

According to a traditional thinking the two seat version of the operational fighter is a key prerequisite for a successful conversion training. However, for Pakistan Air Force the two seat version of the JF-17 is completely out of the picture. “This aircraft is very easy to fly, even easier than the F-16 so we developed a training concept based on a good simulator and we won’t need a two-seater. We’re not yet taking pilots for the JF-17 directly from the academy but we are already taking young pilots from the F-7 squadrons”, said Air Commodore Khalid. “We are developing a full mission simulator with air-to-air, air-to-ground, EW, aerial refueling and Night Vision Googles (NVG) abilities. Before we started we talked to many people but at the end we decided to go with Chinese. They have extensive experience with the simulators so we decided to go with them” he said and added “but, if some customer wants the two-seater we have it on the drawing board”.

Advanced Man-Machine Interface – part II

As much as Pakistan Air Force pilots had to say on the JF-17‘s cockpit interface its technicians had to say on its maintenance features. “Most of the problems on the previous platforms like the F-7 were related to the location of the components. We had to open a lot of panels to access and replace some components. On the JF-17 we tried to gather all of the important components of a particular system on one place so if there is a problem the technician just has to open two or three panels and he will find all the components together there”, said Wing Commander Babar Ali who now works in JF-17 program office but has spent 10 years as a senior technical officer at the flight line. According to him components that have to be checked at a higher frequency, for example every 100 hours are also placed on the first level of depth so when a technician opens a panel that component will be directly in front of him. Similarly, the items thought are going to be the frequently failing items, which according to him are not many on the JF-17, are also positioned on the first level of depth and as a result, the turnaround time for the JF-17 is shorter than for the F-7 even thou there is much more systems to check on the JF-17. When it comes to manpower it is also reduced. “In the F-7 squadron we had 170 people working in the O level maintenance while in the JF-17 squadron with 16 aircraft we have 120. We are using a single crew chief concept very similar to the F-16”, said Wing Commander Babar.

Scheduled maintenance is based on 100 hour interval checks. “Each 100 hours check is a little bit more demanding then the previous one but only slightly until the aircraft reaches 400 hours. The 400 hour check is a bit more demanding than the basic 100 hour check while the 800 hour check is the most demanding. After the 800 hour check it resets and goes from the beginning until the aircraft reaches its designed service life”, said Wing Commander Babar. According to CAC representatives at the Airshow China the JF-17’s service life is currently set at 3000 hours but, as on many contemporary fighters, is a subject to change depending on the wear trends observed during the operational use.

When it comes to the engine “it lives its own life”, explained Wing Commander Babar. “It’s Time Between Overhaul (TBO) is 600 hours with checks at each 100 hours. After it reaches 600 hours the overhaul is due and it can fly for another 600 hours, to its total service life of 1200 hours”.

Logistics

The JF-17 is an aircraft with predictive maintenance concept. It has a comprehensive maintenance and recording system that records over 600 parameters in 300 ms intervals and according to Wing Commander Babar it will always tell the technician what is the health status of a component so he can place a timely order for the new one.

“I can give you one example”, he said. “The fuel filter needs to be changed when it reaches a certain differential pressure level – in this case 1. After each flight the technician can look at the recorded data and see how differential pressure is rising from 0.5 to 0.6 to 0.7 and this gives him a pretty good indication when will the filter have to be replaced”.

When asked if the JF-17’s logistic system is now mature enough, Wing Commander Babar said it works with minimum of surprises. “Every year we define logistics requirements based on our previous experience. Based on previous spare parts consumption trends we are ordering in advance to have minimum surprises. Of course, you can not completely eliminate surprises from the logistic system but you can minimize them. We are doing that by assessing consumption trends and modifying our spare parts requirements twice a year”, he said and added “the reliability for the past five years was unexpectedly high – it was above 95%”.

Production

Another big beneficiary of the JF-17 program is the Pakistan Aeronautical Complex (PAC) in Kamra. Thanks to the JF-17 it progressed from a 25% share in the production of a jet trainer (the K-8 Karakorum) to a 50% share in the production of a jet fighter. “We started with a small pre-production batch of eight aircraft which were used for maturity of the production processes and for the assessment of operational capabilities – a fine tuning of the aircraft. Based on that and the capability enhancements we introduced in the Block 1 we are about to start with the production of the Block 2 aircraft”, said Air Commodore Khalid. “The difference between the Block 1 and the Block 2 aircraft will mostly be in production technologies, some will be in avionics and some in the maintenance facilitation for the ground crew. We found that some areas were not so technician friendly so we want to make them more technician friendly. The engine and the airframe will remain the same”, he said. “As far as manufacturing tempo is concerned it is going according to the Air Force plans, in line with their older types replacement plans so we are not in a hurry. For now we are just matching their retirement tempo”.

Prospect of international sales

For Pakistan Air Force and CAC, selling the JF-17 to a third party would be a significant return of investment but for Chinese foreign policy selling the JF-17 becomes an ideal instrument for broadening of influence especially in the resources rich African countries which are either ineligible or simply cannot afford two to three times more expensive US F-16 Fighting Falcon or the Russian MiG-29.

“We have joint sales and marketing agreements with Chinese. It doesn’t necessarily means we all have to sit together on every meeting but the Chinese side will always be informed about what we are negotiating and we will always know what they are negotiating. The JF-17 is produced in Pakistan Aeronautical Complex (PAC) in Kamra and we can provide everything from manufacturing to documentation and even help with the induction of the aircraft in operational service“, said Air Commodore Khalid.

However, before any JF-17 sales contract is signed there’s still one big obstacle left and that’s the Russian engine. Namely, if the JF-17 becomes too much of a competition to its MiG-29 Russia can always veto it’s sales by simply not agreeing to supply additional RD-93 engines. China is well aware of that and its Guizhou Aircraft Industry Corporation (GAIC) is working on the JF-17 replacement engine, the WS-13 Taishan for some time now (1st flight of the WS-13 equipped FC-1 took place in June 2007). But, according to Vasily Kashin from CAST, a Russian think-thank studying Russian technology transfers to China, this work is very far from over. “Chinese engines are still unsatisfactory in terms of reliability and service life. The problem with WS-13 is not in its design but in production technologies and materials used. The WS-10 Taihang, a replacement engine for the J-10 which is significantly more mature than the WS-13 currently has a TBO of only 300 hours”.

Nevertheless, representatives of the China National Aero-Technology Import and Export Corporation (CATIC) announced at the Airshow China that delegations from Bangladesh, Egypt and Myanmar are coming to test the FC-1 in China in the early 2013. Can this be considered as a sign of a positive developments with the WS-13 engine or China and Russia simply came to an agreement on delivery of extra RD-93 engines – the time will tell. But, when it comes to Pakistan Air Force and its plans to acquire up to 250 JF-17’s Air Commodore Khalid Mehmood was clear: “at this time we are not thinking about the Chinese engine. There are solid agreements between the CATIC and the Russian side guaranteeing us supply of enough RD-93 engines”.

 

[Thorough Pro]

and Drag is one cause loss of air speed

Drag DOES NOT cause the aircraft to 'not fly'. Loss of airspeed does, which can happen due to many causes.

That is not a new thing, even "A" could carry anti ship missiles

the last sentence says it can carry anti-ship missiles.

 

[CriticalThought]

and Drag is one cause loss of air speed

You keep flying because your engine keeps overcoming drag with thrust. Drag doesn't stop you from flying, loss of thrust does.

 

[Thorough Pro]

Probably you missed it.

There were few reports about AESA Radar system such as KLJ A?
Any confirmation about it?

We are saying the same thing

You keep flying because your engine keeps overcoming drag with thrust. Drag doesn't stop you from flying, loss of thrust does.

 

[CriticalThought]

Probably you missed it.

We are saying the same thing

No we are not. I have quoted your original post below. The sentence 'lift is way more than drag' implies that lift and drag are opposing forces, and the net force makes the plane fly. That is wrong. They are not opposing forces. If you read books on aerodynamics, there is s component of drag that is caused due to the process of creating lift - you can't produce lift without experiencing drag. But at supersonic speeds drag is also caused by things such as wave shock. The overall ratio of lift to drag is used in various computations of aerodynamic parameters.

Yes, but comparatively lift is way more than the drag, that is why all the planes fly