JF-17 Thunder Multirole Fighter [Thread 6]

[gambit]

A slightly unrelated question about composites and RCS reduction. How exactly does using composites reduce the RCS? From the little I know composites are simply transparent to radar. So when we say RCS reduction using composites are we saying that we replace the entire internal structure of a part (lets say the tail) with a composite part? Because a composite skin or some parts of composites will just mean reflections will happen from the internal metal structure.

OR are there radar absorbing composites as well? That would be neat, just replace the skin, keeping the internal structure the same.

The most important thing you should keep in mind is that the RCS value is essentially a fictitious value. It is a fiction, not in the sense that it is imaginary like a science fiction novel, but that it can be changed, and how that value changes depends on the relationship between materials and the structural complexity of the body.

In radar detection, the sphere is usually the body of standardization and calibration. The sphere is structurally simple and no matter the approach angle, the radar sees the same RCS value.

FACT: The simpler the structure, the greater the effects of materials on RCS.

What this mean is that a steel sphere will reflects greater than a plastic sphere. What this also mean is that there is a corollary to the above fact: That the more structurally complex the body, the lesser the effects of materials on RCS.

A basic outline of how complex structures affects final RCS is here...

Fundamentals of Stealth Design & Concepts of RCS Reduction | Page 3

It does not mean that if an existing -- or pre 5th gen -- fighter have its skin re-done with EM absorber, the materials will have no effects on final RCS. The materials DO have effects on RCS reduction. The issue is whether the reduction level will have any tactical efficacy at all. Final RCS will decrease, but if the detection range decrease from 100 km to 95 km, it is not financially worthwhile to expend the necessary resources just to gain a mere 5 km advantage, if using the word 'advantage' generously, over the enemy radar.

Tactically speaking, a pilot or a flight should have 30-45 seconds over the enemy in order to re-position himself or re-array the flight into superior combat postures. Unfortunately, that 30-45 seconds time span is rarely achieved when the approaching speed of both sides is in Mach, making that 5 km difference, from non-composite skin to composite skin, pretty much worthless. So the analyses must at least hint at the possibility that any RCS reduction measures onto an existing -- pre 5th gen -- fighter can give the pilot that 30-45 seconds gain, which means the RCS reduction measures should reduce detection range by at least 50%: from 100 km down to 50 km.

Understand that I am playing a bit loose with the numbers since we, or rather I, are treading on the sensitive information line.

Anyway...If your analyses reveals that your proposal cannot give your pilots that tactical advantageous time span to re-position himself and his flight into superior combat postures, whether it is higher altitudes to fire the missiles, or lower altitudes to sneak up on ground targets, then you are essentially wasting your nation's money. It is not a blanket issue. Each fighter platform must be examined individually. Why is it that the US spent money on RCS reduction measures on the F-18 Super Hornet but not on the F-15E ? Maybe somehow the -18's body already have a lower RCS than the -15 so composites on the -18 those RCS reduction measures did give its pilot that time span advantage. Maybe not 30 seconds but only a 20 seconds advantage but the US Navy decided it was tactically worthwhile anyway considering the nature of the Navy's worldwide mission scope.

So while the entire issue can be dissected and isolated into discrete components, financial on one part of the table, tactics on another part of the table, technical feasibility on another part of the table, potential adversary sophistication on another part of the table, etc...etc..., the 'go or no-go' decision on the project rests on all factors.

 

[Hell hound]

The most important thing you should keep in mind is that the RCS value is essentially a fictitious value. It is a fiction, not in the sense that it is imaginary like a science fiction novel, but that it can be changed, and how that value changes depends on the relationship between materials and the structural complexity of the body.

In radar detection, the sphere is usually the body of standardization and calibration. The sphere is structurally simple and no matter the approach angle, the radar sees the same RCS value.

FACT: The simpler the structure, the greater the effects of materials on RCS.

What this mean is that a steel sphere will reflects greater than a plastic sphere. What this also mean is that there is a corollary to the above fact: That the more structurally complex the body, the lesser the effects of materials on RCS.

A basic outline of how complex structures affects final RCS is here...

Fundamentals of Stealth Design & Concepts of RCS Reduction | Page 3

It does not mean that if an existing -- or pre 5th gen -- fighter have its skin re-done with EM absorber, the materials will have no effects on final RCS. The materials DO have effects on RCS reduction. The issue is whether the reduction level will have any tactical efficacy at all. Final RCS will decrease, but if the detection range decrease from 100 km to 95 km, it is not financially worthwhile to expend the necessary resources just to gain a mere 5 km advantage, if using the word 'advantage' generously, over the enemy radar.

Tactically speaking, a pilot or a flight should have 30-45 seconds over the enemy in order to re-position himself or re-array the flight into superior combat postures. Unfortunately, that 30-45 seconds time span is rarely achieved when the approaching speed of both sides is in Mach, making that 5 km difference, from non-composite skin to composite skin, pretty much worthless. So the analyses must at least hint at the possibility that any RCS reduction measures onto an existing -- pre 5th gen -- fighter can give the pilot that 30-45 seconds gain, which means the RCS reduction measures should reduce detection range by at least 50%: from 100 km down to 50 km.

Understand that I am playing a bit loose with the numbers since we, or rather I, are treading on the sensitive information line.

Anyway...If your analyses reveals that your proposal cannot give your pilots that tactical advantageous time span to re-position himself and his flight into superior combat postures, whether it is higher altitudes to fire the missiles, or lower altitudes to sneak up on ground targets, then you are essentially wasting your nation's money. It is not a blanket issue. Each fighter platform must be examined individually. Why is it that the US spent money on RCS reduction measures on the F-18 Super Hornet but not on the F-15E ? Maybe somehow the -18's body already have a lower RCS than the -15 so composites on the -18 those RCS reduction measures did give its pilot that time span advantage. Maybe not 30 seconds but only a 20 seconds advantage but the US Navy decided it was tactically worthwhile anyway considering the nature of the Navy's worldwide mission scope.

So while the entire issue can be dissected and isolated into discrete components, financial on one part of the table, tactics on another part of the table, technical feasibility on another part of the table, potential adversary sophistication on another part of the table, etc...etc..., the 'go or no-go' decision on the project rests on all factors.

sir few days ago matter relating fuel consumption during taking off and getting at optimal altitude was being discussed here but it end up rising more question then it solved. it will be greatly appreciated if you can shed some light on it from f 16's prospective and from general prospective too.thanks

 

[Dazzler]

 

[Tempest II]

 

[RAMPAGE]

The most important thing you should keep in mind is that the RCS value is essentially a fictitious value. It is a fiction, not in the sense that it is imaginary like a science fiction novel, but that it can be changed, and how that value changes depends on the relationship between materials and the structural complexity of the body.

In radar detection, the sphere is usually the body of standardization and calibration. The sphere is structurally simple and no matter the approach angle, the radar sees the same RCS value.

FACT: The simpler the structure, the greater the effects of materials on RCS.

What this mean is that a steel sphere will reflects greater than a plastic sphere. What this also mean is that there is a corollary to the above fact: That the more structurally complex the body, the lesser the effects of materials on RCS.

A basic outline of how complex structures affects final RCS is here...

Fundamentals of Stealth Design & Concepts of RCS Reduction | Page 3

It does not mean that if an existing -- or pre 5th gen -- fighter have its skin re-done with EM absorber, the materials will have no effects on final RCS. The materials DO have effects on RCS reduction. The issue is whether the reduction level will have any tactical efficacy at all. Final RCS will decrease, but if the detection range decrease from 100 km to 95 km, it is not financially worthwhile to expend the necessary resources just to gain a mere 5 km advantage, if using the word 'advantage' generously, over the enemy radar.

Tactically speaking, a pilot or a flight should have 30-45 seconds over the enemy in order to re-position himself or re-array the flight into superior combat postures. Unfortunately, that 30-45 seconds time span is rarely achieved when the approaching speed of both sides is in Mach, making that 5 km difference, from non-composite skin to composite skin, pretty much worthless. So the analyses must at least hint at the possibility that any RCS reduction measures onto an existing -- pre 5th gen -- fighter can give the pilot that 30-45 seconds gain, which means the RCS reduction measures should reduce detection range by at least 50%: from 100 km down to 50 km.

Understand that I am playing a bit loose with the numbers since we, or rather I, are treading on the sensitive information line.

Anyway...If your analyses reveals that your proposal cannot give your pilots that tactical advantageous time span to re-position himself and his flight into superior combat postures, whether it is higher altitudes to fire the missiles, or lower altitudes to sneak up on ground targets, then you are essentially wasting your nation's money. It is not a blanket issue. Each fighter platform must be examined individually. Why is it that the US spent money on RCS reduction measures on the F-18 Super Hornet but not on the F-15E ? Maybe somehow the -18's body already have a lower RCS than the -15 so composites on the -18 those RCS reduction measures did give its pilot that time span advantage. Maybe not 30 seconds but only a 20 seconds advantage but the US Navy decided it was tactically worthwhile anyway considering the nature of the Navy's worldwide mission scope.

So while the entire issue can be dissected and isolated into discrete components, financial on one part of the table, tactics on another part of the table, technical feasibility on another part of the table, potential adversary sophistication on another part of the table, etc...etc..., the 'go or no-go' decision on the project rests on all factors.

Why not simply work on a more powerful radar to achieve the 35-40 second gain?

 

[gambit]

sir few days ago matter relating fuel consumption during taking off and getting at optimal altitude was being discussed here but it end up rising more question then it solved. it will be greatly appreciated if you can shed some light on it from f 16's prospective and from general prospective too.thanks

Generally, fuel consumption on take off depends on several factors:

- Type of mission which set the weapons load.
- Elevation which affects air density.
- Engine version.

Believe it or not, given long enough runway, a fully loaded air-ground F-16 can take off without afterburner, but that runway would be at Edwards AFB where the Space Shuttle lands. A rough figure would be 1000-1200 pounds of fuel in AB for take off for an air-ground config, and about 10% less for an air-air config.

A 'take off' does not end with wheels up. The 'take off' stage actually ends when the aircraft achieved enough aerodynamic support from the wings that the pilot can throttle back, and even then, this stage is not fixed.

Say that there is a bunch of bad guys just a few klicks outside the base with MANPADs. The take off stage is where I am most vulnerable because I do not have enough altitude room for maneuver and there is not enough airspeed for me to exploit aerodynamic forces for rapid maneuvers. So in order for me to get that airspeed as soon as possible, I have to stay in AB for longer and as soon as wheels up I have to increase pitch up sooner to gain safe altitude. All of this cost fuel. For this scenario, an A-G config that make me heavy will use up even more fuel than the lighter A-A config. On the other hand, if I can afford to stay shallow in pitch so my wings can gain as much aerodynamics support as possible, I can throttle back sooner and will consume less fuel.

In both situations, the take off stage ends at different points in flight.

For a visual representation of the stages of flight...

As you can see, the take off stage is actually quite away from the runway/base and higher in altitude than most people believe to be. The military side of it is not that much different, even if you factor in afterburner. Gears up is still around 30-40 ft, then pitch up to gain altitude, but the actual take off stage is not complete until I am confident that I have enough altitude below me and enough airspeed for maneuvers if I have to.

There is no fixed quantity that I can give regarding fuel consumption at take off precisely because there are many variables involved.

 

[aftab_s81]

Interesting video about avionics manufacturing and other manufacturing at PAC website. Unfortunately can not provide links b/c of the restrictions of this forum. If anybody can do that, would be great.

BTW, PAC re-wamped website is a good one. They are working on presentation part as well.

 

[Windjammer]

Paris Air Show 2015: Aircraft To Watch
Graham Warwick | Aviation Week & Space Technology

PAC JF-17 Thunder
In service since 2010, Pakistan’s JF-17 lightweight fighter has been developed jointly by China’s Chengdu Aircraft and Pakistan Aeronautical Complex, which produces the aircraft at its Kamra factory.

Photo:
Aldo Bidini/Wikimedia Commons

 

[Donatello]

Generally, fuel consumption on take off depends on several factors:

- Type of mission which set the weapons load.
- Elevation which affects air density.
- Engine version.

Believe it or not, given long enough runway, a fully loaded air-ground F-16 can take off without afterburner, but that runway would be at Edwards AFB where the Space Shuttle lands. A rough figure would be 1000-1200 pounds of fuel in AB for take off for an air-ground config, and about 10% less for an air-air config.

A 'take off' does not end with wheels up. The 'take off' stage actually ends when the aircraft achieved enough aerodynamic support from the wings that the pilot can throttle back, and even then, this stage is not fixed.

Say that there is a bunch of bad guys just a few klicks outside the base with MANPADs. The take off stage is where I am most vulnerable because I do not have enough altitude room for maneuver and there is not enough airspeed for me to exploit aerodynamic forces for rapid maneuvers. So in order for me to get that airspeed as soon as possible, I have to stay in AB for longer and as soon as wheels up I have to increase pitch up sooner to gain safe altitude. All of this cost fuel. For this scenario, an A-G config that make me heavy will use up even more fuel than the lighter A-A config. On the other hand, if I can afford to stay shallow in pitch so my wings can gain as much aerodynamics support as possible, I can throttle back sooner and will consume less fuel.

In both situations, the take off stage ends at different points in flight.

For a visual representation of the stages of flight...

View attachment 227156
As you can see, the take off stage is actually quite away from the runway/base and higher in altitude than most people believe to be. The military side of it is not that much different, even if you factor in afterburner. Gears up is still around 30-40 ft, then pitch up to gain altitude, but the actual take off stage is not complete until I am confident that I have enough altitude below me and enough airspeed for maneuvers if I have to.

There is no fixed quantity that I can give regarding fuel consumption at take off precisely because there are many variables involved.

Well, climbout profiles differ from mission to mission. Even civilian airliners operating in potential in-secure zones would have a steeper than normal climb and or descent. Also, many airports, like in USA enforce strict Noise Abatement Procedures, meaning a plan has to take off and climb faster than usual so it can gain height quickly.

How much does F-16 or a typical 4th Gen fighter burn fuel on takeoff, with or without AB? Like 10 % or 20%

 

[Windjammer]

JAAG TV ‏@JaagAlerts 15 mins15 minutes ago
Just In: 3 #PAF JF-17 Thunder leave for 51st [HASHTAG]#Paris[/HASHTAG] Air Show

 

[fatman17]

3 JF17 have left for Paris airshow along with a C130 carrying ground support staff and equipment

 

[Bratva]

So instead of raising the third squadron, the assigned the last batch of block-1 to existing black panthers

 

[ACE OF THE AIR]

So instead of raising the third squadron, the assigned the last batch of block-1 to existing black panthers

A new wing has been created?

 

[aftab_s81]

Good to see!

 

[nomi007]