JF-17/FC-1 Fighter Aircraft thread

[Munir]

Re: JF-17/FC-1 Fighter Aircraft thread 2009

That's correct but what about JF-17 ? I can't say whether it has flaperons or ailerons.

The F16 has simpler FBW then JF17. I understand that most people will start jumping to conclusions but just look at the number of moveable wingparts... The F16 uses flaps and elevators to control movement. Continuesly. It has slats to improve airfow when flying low speed. To control the movement it needs a lot bigger elevators then they had designed in the beginning but after block15 that was corrected. Most people do not know that the flaps of the F16 move also upwards...

The JF17 has a fully wing with ailerons and flaps. So not the simpler flaperons (that is when you use flaps and ailerons as one instrument). so the FBW needs not only master flaps but also ailerons. And the ailerons are not connected to eleators. Which I think in the next version will we altered cause it has its handy effects like a less stressed aileron... And the more simple design to add extra wingpylon...

Talking about FBW... The LCA (just as an example like the MK2) has even more basic FBW cause it has fewer moveable parts. The parts are much bigger cause they still need to alter movement. And that is also what adds huge drag or waste of kinetic energy. And is also contributing to more RCS. So in fact you can say that for speed (hit and run) and load you can use a delta as the best design. For agility and power you should go for the usual. If you want a good compromis you need a canarded delta but with canrads that add lift so you can play with it more efficiently.

Hope you guys don't mind for a little tech part. If you ask me personally... The MKI would have been a better plane if they skipped TVC and added better canards. TVC is handy for some parts of the flight but adding that much weight for minor improvement is not the optimum. Int he future you will do anything to keep your kinetic energy high... Doing fancy aerobatic is nice when you wanna impress some customers but in air war of these days it is hadly worth anything. Stealth, radar and ECM are much more important.

 

[crobato]

Re: JF-17/FC-1 Fighter Aircraft thread 2009

The F16 has simpler FBW then JF17. I understand that most people will start jumping to conclusions but just look at the number of moveable wingparts... The F16 uses flaps and elevators to control movement. Continuesly. It has slats to improve airfow when flying low speed. To control the movement it needs a lot bigger elevators then they had designed in the beginning but after block15 that was corrected. Most people do not know that the flaps of the F16 move also upwards...

The JF17 has a fully wing with ailerons and flaps. So not the simpler flaperons (that is when you use flaps and ailerons as one instrument). so the FBW needs not only master flaps but also ailerons. And the ailerons are not connected to eleators. Which I think in the next version will we altered cause it has its handy effects like a less stressed aileron... And the more simple design to add extra wingpylon...

Talking about FBW... The LCA (just as an example like the MK2) has even more basic FBW cause it has fewer moveable parts. The parts are much bigger cause they still need to alter movement. And that is also what adds huge drag or waste of kinetic energy. And is also contributing to more RCS. So in fact you can say that for speed (hit and run) and load you can use a delta as the best design. For agility and power you should go for the usual. If you want a good compromis you need a canarded delta but with canrads that add lift so you can play with it more efficiently.

Very good. FBW is best implemented with having more control surfaces, not less.

The worst possible configuration is when you got nothing but elevons---two control surfaces that has to act as flaps, ailerons and elevators all at the same time.

Hope you guys don't mind for a little tech part. If you ask me personally... The MKI would have been a better plane if they skipped TVC and added better canards. TVC is handy for some parts of the flight but adding that much weight for minor improvement is not the optimum. Int he future you will do anything to keep your kinetic energy high... Doing fancy aerobatic is nice when you wanna impress some customers but in air war of these days it is hadly worth anything. Stealth, radar and ECM are much more important.

I second that. Its better to have one or the other, TVC or canards, then work your FBW software for greater optimization. Canards are better for high speed maneuver---they exert superior control authority at higher speeds than nozzle exhaust---and it is maneuverability at high speeds that count these days.

 

[Indianfighter]

Re: JF-17/FC-1 Fighter Aircraft thread 2009

If the F-16 weighs 3 tons more, then its compensated with a higher thrust. So your logic is flawed.

True, F-16 can compensate for it's weight by more thrust, but that is not an implication that it's "flight-regime" is the same as a JF-17. By your logic, a J-11 also is compensated by much much higher thrust, and so it should manage to maintain a JF-17's profile.

The point is that raw size and weight do matter in aerodynamics. The matter of high speed interceptor vs. low flying agile fighter is a different one altogether.

Even a scale model of a JF-17 made of the same material will not fly exactly the same as the full-size JF-17.

That's what got me wondering : A JF-17 and an F-16 are 2 different beasts altogether, but having near congruent wing designs. This is just a point to ponder; let's not start a quarrel over this.

carrying munitions increases drag which obviously effects the aircraft performance, and its aerodynamics.

Increasing its mass doesnt effect aerodynamics, aerodynamics is a factor of its external shape effecting airflow and flight performance.

Note I mentioned dummy missiles and 'real' missiles, or something like empty shells vs. the actual munitions. So the outward aerodynamics faced is congruent, but weights are different.

The F16 has simpler FBW then JF17. I understand that most people will start jumping to conclusions but just look at the number of moveable wingparts... The F16 uses flaps and elevators to control movement. Continuesly. It has slats to improve airfow when flying low speed. To control the movement it needs a lot bigger elevators then they had designed in the beginning but after block15 that was corrected. Most people do not know that the flaps of the F16 move also upwards...

The JF17 has a fully wing with ailerons and flaps. So not the simpler flaperons (that is when you use flaps and ailerons as one instrument). so the FBW needs not only master flaps but also ailerons.

Please note that F-16's flaps double as ailerons (hence the name flaperons). If a JF-17 has ailerons, then it won't use flaps during flight (flaps are used only during takeoff/land). So the number of control surfaces are the same as an F-16 : rudder, elevator and aileron/flaperon = 3 in all.

 

[crobato]

Re: JF-17/FC-1 Fighter Aircraft thread 2009

True, F-16 can compensate for it's weight by more thrust, but that is not an implication that it's "flight-regime" is the same as a JF-17. By your logic, a J-11 also is compensated by much much higher thrust, and so it should manage to maintain a JF-17's profile.

Nonsense. Flight regime is determined by military requirements. For example, I want to target my optimal combat altitude at 20,000 feet, which is the most common altitude statistically for combat engagement since World War II. Your speed range is about Mach 0.5 to Mach 0.8. Even here, weight is already predetermined, at least to have full interior fuel, two to four short range AAMs and a full load for the cannon.

The engineers will then work on these parameters.

Please note that F-16's flaps double as ailerons (hence the name flaperons). If a JF-17 has ailerons, then it won't use flaps during flight (flaps are used only during takeoff/land). So the number of control surfaces are the same as an F-16 : rudder, elevator and aileron/flaperon = 3 in all.

You don't know what a flap does. It is meant to extend wing chord, which increases lift. A flap therefore extends forward or backward to vary the wing chord. If a flaperon is used as an aileron, which is to deflect upward or backward, it cannot work as a flap simultaneously.

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Saying it is used for taking off and landing is just so fundamentally wrong. It is used to lower stall speed, which makes the plane do tighter, slower turns.


For an aileron to work, one has to deflect up and the other down, to cause the plane to roll.

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[Engineer]

Re: JF-17/FC-1 Fighter Aircraft thread 2009

You see the point is that aircraft don't fly in vacuum. Mass does affect aircraft aerodynamics of F-16 and JF-17, even if they are roughly of the same dimensions and have a wing-design that's matched.

Aerodynamics concern with the air flow around the aircraft, and has nothing to do with mass. You are confusing it with dynamics.

 

[mean_bird]

Re: JF-17/FC-1 Fighter Aircraft thread 2009

True, F-16 can compensate for it's weight by more thrust, but that is not an implication that it's "flight-regime" is the same as a JF-17. By your logic, a J-11 also is compensated by much much higher thrust, and so it should manage to maintain a JF-17's profile.

Please don't infer what you want from my statement...I never said anything about J-11. We are talking JF-17 and F-16 because they have similar wing design, and J-11 do not share this. A plane's profile is determined by its aerodynamic behavior.

The point is that raw size and weight do matter in aerodynamics. The matter of high speed interceptor vs. low flying agile fighter is a different one altogether.

Even a scale model of a JF-17 made of the same material will not fly exactly the same as the full-size JF-17.

You are confusing two things. If you add weight, it becomes heavy and slow so its dynamics change but its aerodynamic behavior does not.

For example, if JF-17 is meant to have optimal performance at low speed and lower altitudes, just by adding weight will not change its optimal performance for high speed.

Be careful I am using the word "optimized". Sure it can go supersonic, climb to different altitudes, etc but its shape and design is optimized for subsonic speeds. It will remain optimized for that behavior even if you added 2 tons of weight just that the absolute performance values would decrease.

So if its LERX were providing lift for lower speed, they will continue to do so even if JF-17 was made of a heavier metal. Performance will be effected but the design will still behave the same.

Aerodynamic behavior is determined by shape not weight...weight can only change the values of the parameters.

 

[Delbert]

Re: JF-17/FC-1 Fighter Aircraft thread 2009

Honestly speaking, in my opinion I don't see the PLAAF to deploy the JF-17.

I do believe they would rather purchase J-10's than purchasing huge amounts of JF-17.

 

[Munir]

Re: JF-17/FC-1 Fighter Aircraft thread 2009

I didn't think the Chinese would buy large numbers of K8. Still I am suprised to see that they have added large numbers. J10 seems to be a nice chap and I think the only resaon would be diversity and being cheaper. We will see. Let us look back in 2014...

 

[Londo Molari]

Re: JF-17/FC-1 Fighter Aircraft thread 2009

Honestly speaking, in my opinion I don't see the PLAAF to deploy the JF-17.

I do believe they would rather purchase J-10's than purchasing huge amounts of JF-17.

Lets not start this argument again please. I think the mods have said as much before.

 

[mean_bird]

Re: JF-17/FC-1 Fighter Aircraft thread 2009

Some recent information from Keymag

Some latest info I got from my sources

- JF-17 has been fitted with IFR
- Most of the weapons in PAF's warehouse have been integrated
- from Pt-04, it is full FBW because of some aerodynamic changes which made it necessary.
- In the first batch,there wont be a dedicated station for a targeting pod. it will be fitted on a wing station instead
- targeting information can be shared via data link especially in a formation where not all the aircraft are fitted by one. A 'pathfinder' aircraft will have it and be data-linked to others.
- a FLIR may be installed in the nose (possibly at a later date )
- It can carry multiple items per station


Others
- Recently, some changes have been done to the Rudder as it developed some vibrations during aero-elastic tests
- In recent training/testing flights, PAF F-16 veteran pilots have been left stunned by what the JF-17 was able to do and getting the better of them.

cheers