JF-17 Block-3 -- Updates, News & Discussion

[Dreamer.]

nope, i don’t need it, i know for a fact that’s how PAC works. They get assigned a production line serial number which we don’t know what it actually means, then a PAF one and a PAF registration

The factory numbers were dissected by some members some time back in another JF-17 thread. I think @Pakistan Space Agency might know better.

 

[The Raven]

Who said that these storage cavities are having larger width. IMO the cavity width might be varying and minimum could be less than a cm and max may be 3-4 cm.

I am again repeating that if you are revealing tech info IAW valid source then quote it, otherwise using a presume venn diagram to satisfy your logic will not be acceptable to us, who actually worked on such fighter aircraft.

This is not the first time a person from PAC saying green shaded area reveals fuel storage area and none of them referred the venn diagram.

What I understand from the discussion on green shaded area, most of the respected members are considering pilot's safety and space available. Locating the fuel storage on both sides of the outer cockpit with all "design safeties" will not add up any insecurity to the pilot.c

Furthermore, IMO location of the fuel cavities is directly linked with location of IFR probe. It is certainly a smart use of space to increase fuel capacity.

If the Block-III has fuel stored around the cockpit, as far as I know this would be the first fighter aircraft, actually, the first modern aircraft, to have fuel stored around the cockpit. I am unaware of any other modern fighter with this design. Would you know if any other aircraft designer has adopted a similar design? I don't know of any pilot who would be willing to fly, let alone fight, in a fighter with fuel stored around the cockpit, and despite the bravery and dedication of the PAF pilots, I'm fairly certain they would have similar reservations. Incidentally, what would happen to the fuel if the pilot had to eject on take off, such as engine failure or bird strike, would the fuel storage tanks be sufficiently protected against the rocket motor blast of the ejection seat? Are the fuel cells self-sealing and armoured? I don't see any armour panels around the cockpit to protect against cannon fire, for example, see the armour plating of the Su-25 and A-10 thunderbolt.

 

[TigerOfMysore]

Not sure why people are laboring on this green, non-green issue. It is super simple and does not relate to it being an area for fuel tanks. Even the yellow surfaces are coated in a material that allows for stronger paint bonding. The green surfaces could be the application of some additional bonding material to allow for stronger paint adhesion. The color difference could also be associated with difference in manufacturing process. The green does NOT represent areas of fuel storage alone, nor does it represent composites.

If there was one thing I took away from this Cringey BOL video was the lack of composites in the JF-17. Though disappointing it opens up for a potential later block with areas that are composite built or reinforced, enabling a better thrust to weight ratio.

 

[Iron Shrappenel]

Not sure why people are laboring on this green, non-green issue. It is super simple and does not relate to it being an area for fuel tanks. Even the yellow surfaces are coated in a material that allows for stronger paint bonding. The green surfaces could be the application of some additional bonding material to allow for stronger paint adhesion. The color difference could also be associated with difference in manufacturing process. The green does NOT represent areas of fuel storage alone, nor does it represent composites.

If there was one thing I took away from this Cringey BOL video was the lack of composites in the JF-17. Though disappointing it opens up for a potential later block with areas that are composite built or reinforced, enabling a better thrust to weight ratio.

Are the control surfaces of JF-17 thunder made of aluminum alloy 7050 ?

 

[TigerOfMysore]

Are the control surfaces of JF-17 thunder made of aluminum alloy 7050 ?

Cannot tell you. It is very difficult to ascertain what materials are used. They could be any advanced alloy or organic/ceramic materials. It is almost impossible to know unless part of the program at the metallurgy level. If you are alluding that some of the control surfaces could be composites, perhaps, but almost impossible to ascertain.

 

[The Raven]

I don't think there has ever been an official breakdown of the composition of the airframe comprising composites (correct me if I am wrong @Deino). As far as I know, most of the airframe is standard metal alloy to keep the cost down.

 

[Iron Shrappenel]

Cannot tell you. It is very difficult to ascertain what materials are used. They could be any advanced alloy or organic/ceramic materials. It is almost impossible to know unless part of the program at the metallurgy level. If you are alluding that some of the control surfaces could be composites, perhaps, but almost impossible to ascertain.

No I'm looking up some things... So wanted to know wrt that... If I can make sense of it.. I'll post my findings here... Thank you for your input.

 

[Marker]

If the Block-III has fuel stored around the cockpit, as far as I know this would be the first fighter aircraft, actually, the first modern aircraft, to have fuel stored around the cockpit. I am unaware of any other modern fighter with this design. Would you know if any other aircraft designer has adopted a similar design? I don't know of any pilot who would be willing to fly, let alone fight, in a fighter with fuel stored around the cockpit, and despite the bravery and dedication of the PAF pilots, I'm fairly certain they would have similar reservations. Incidentally, what would happen to the fuel if the pilot had to eject on take off, such as engine failure or bird strike, would the fuel storage tanks be sufficiently protected against the rocket motor blast of the ejection seat? Are the fuel cells self-sealing and armoured? I don't see any armour panels around the cockpit to protect against cannon fire, for example, see the armour plating of the Su-25 and A-10 thunderbolt.

Usually fuel cells/compartments or storage cavities are not located around the cockpit of an aircraft.

However there are aircraft whose fuel compartments are located behind the pilot ejection seat. Of course the ejection mechanism for both canopy and seat are not critically close to the fuel compartment. As there are no connecting fuel pipes routed inside the cockpit and the fuel compartment is 100% sealed therefore chances of fuel vapour inside the cockpit is out of question.

I am unaware of any other jet aircraft having fuel storage cavities located outer sides of the cockpit.

Appreciate that liquid fuel, (JF-17 uses JP-10), will burn but fuel vapour will explode sucking the air.

The fuel storage cavities located around cockpit are definitely being sealed with fire proof "covers" and fuel connecting pipes and IFR probe are located outside the cockpit. Hence possibility of fuel vapours presence inside the cockpit do not exist.

Pilots fly military 4 and 4.5 jets already knew that they are flying very sophisticated flying machines which will not tolerate a micro second delay in response or human ignorance or complacency . They know that they are flying most risky machine. Any human, mechanical or natural error will cause catastrophic results.
However these pilots require good cockpit environment. Even slight existence of fuel vapours smell inside the cockpit may cause uneasiness. Therefore fuel storage design around cockpit should be fire proof and fuel leak free. I am sure Chinese designers must have catered for both fuel leak and fire for this type of arrangement.

All aviation military designs consider not only the mission profile but also the safety of pilot and aircraft. The design is "optimised". Risk factor do exist but reduced considerably using various technologies. It will be interesting to know tech details of this type of arrangement.

 

[TigerOfMysore]

No I'm looking up some things... So wanted to know wrt that... If I can make sense of it.. I'll post my findings here... Thank you for your input.

Yaar I think there is a very good chance that 7050 is used on the JF-17. But could not tell you how much, where and which temper. But a good bet would be fuselage, wings and any other high stress areas or areas where there is a strong likelihood of stress corrosion cracking. But this is entirely speculation.

 

[Marker]

The green does NOT represent areas of fuel storage alone, nor does it represent composites.

Valid source please. Also quote the reason of this type of colour application.

 

[CriticalThought]

Valid source please. Also quote the reason of this type of colour application.

You do realize that you are showing a comprehension issue here. That is, your inability to comprehend what the PAC technician is saying. Or that fact, that these crews are blindly following instructions and speaking the words that they have been taught. Somebody taught them to say, 'Green areas represent fuel' and that is all they will say. None of the managers, supervisors, or technicians is an engineer who would appreciate the engineering or aerodynamic significance of what they are doing.

 

[Akh1112]

You do realize that you are showing a comprehension issue here. That is, your inability to comprehend what the PAC technician is saying. Or that fact, that these crews are blindly following instructions and speaking the words that they have been taught. Somebody taught them to say, 'Green areas represent fuel' and that is all they will say. None of the managers, supervisors, or technicians is an engineer who would appreciate the engineering or aerodynamic significance of what they are doing.

As I had said like 3 days ago, the engineer was talking in the context of the wing.

 

[The Raven]

Usually fuel cells/compartments or storage cavities are not located around the cockpit of an aircraft.

However there are aircraft whose fuel compartments are located behind the pilot ejection seat. Of course the ejection mechanism for both canopy and seat are not critically close to the fuel compartment. As there are no connecting fuel pipes routed inside the cockpit and the fuel compartment is 100% sealed therefore chances of fuel vapour inside the cockpit is out of question.

I am unaware of any other jet aircraft having fuel storage cavities located outer sides of the cockpit.

Appreciate that liquid fuel, (JF-17 uses JP-10), will burn but fuel vapour will explode sucking the air.

The fuel storage cavities located around cockpit are definitely being sealed with fire proof "covers" and fuel connecting pipes and IFR probe are located outside the cockpit. Hence possibility of fuel vapours presence inside the cockpit do not exist.

Pilots fly military 4 and 4.5 jets already knew that they are flying very sophisticated flying machines which will not tolerate a micro second delay in response or human ignorance or complacency . They know that they are flying most risky machine. Any human, mechanical or natural error will cause catastrophic results.
However these pilots require good cockpit environment. Even slight existence of fuel vapours smell inside the cockpit may cause uneasiness. Therefore fuel storage design around cockpit should be fire proof and fuel leak free. I am sure Chinese designers must have catered for both fuel leak and fire for this type of arrangement.

All aviation military designs consider not only the mission profile but also the safety of pilot and aircraft. The design is "optimised". Risk factor do exist but reduced considerably using various technologies. It will be interesting to know tech details of this type of arrangement.

Could you please valid sources for the claims you making, highlighted in bold, especially for the JF-17's "fire proof covers around the cockpit". I would liked to have seen the look on the faces of the Chinese engineers when the folks at PAF/PAC allegedly asked them t install fuel tanks around the cockpit.

 

[Marker]

None of the managers, supervisors, or technicians is an engineer who would appreciate the engineering or aerodynamic significance of what they are doing.

By the way, who are you?

Please say that you belong to aviation industry, aviation engineer and designer.

Even if you are, you.have no right to speak about PAF Technicians, NCOs, JCOs and Officers working in PAC. As far as I know, PAC manpower consist of highly qualified, experienced people and definitely know about "aerodynamics" and its "significance".
Among them few are Ph Ds.

If these technicians or officers are saying something then please consider as a fact unless you, yourself work on or affiliate with JF-17 and then please do correct my inference.

 

[Marker]

Could you please valid sources for the claims you making, highlighted in bold, especially for the JF-17's "fire proof covers around the cockpit". I would liked to have seen the look on the faces of the Chinese engineers when the folks at PAF/PAC allegedly asked them t install fuel tanks around the cockpit.

The famous tweet --- T-37