JF-17/FC-1 Fighter Aircraft thread

[crobato]

Re: PLAAF and PLAN Paint Schemes

Hello all,

as far as the PLAAF and PLAN Flankers go, I like their colors. While the various low tone and dark tone greys may not be very pleasing on the eyes, the various tones of grey work well in a number of environments. It has been proven. The shades of paint can vary with terrain an aircraft may be found in. In the west, grey has become popular. If I remember correctly, the US Navy and Marine Corps began using the lighter shades of grey in the 1980s replacing a number of whites, two tone greys and other high viz colors. The A7Es and F-4N/S aircraft provide the best examples of the changes. The F-14As and later models also changed. The Hornets only briefly had more color and then arrived in the standard Tactical Paint Scheme. On the USAF side, the A-10s were the last tactical birds to go grey, starting in the early 1990s. We had a grey A-10 that for the longest time was "The Grey One" while all the other aircraft in the wing were the two tone Green/Dark Green. The F-15Es sport a very dark grey opposed to the two tone greys of F-15C/Ds.

The schemes I have seen for the PLAAF/PLAN Flankers would fit excellent in comflict at sea as well as medium altitudes. They would also work well in poor weather and visibility conditions. Some nations adopt similar approaches to aircraft, other operate on thier own. The various F-16s of the world have adopted lighter shades of grey. Maylasia has a really nice looking and dark scheme for their Hornets, as does the Royal Canadian Air Force.

As far as black aircraft paint, it has been tried. For a time, USN A6s,A7s and F4s sported black nose cones. This was usually done for anti-glare purposes. But as someone mentioned above, the aircraft sticks out at great distance. Similar effects occur in having dark painted engine intakes. The PLAN and PLAAF Flankers look great in their dark tones.

Raven

You make a good point, especially since China tend to be covered by a grey pollution caused haze, the grey even looks less visible.

I have not noticed that black tends to be antiglare while white is glaring. I noticed that the RuAF MiG-29s tend to have either black or grey noses, the Su-27s came with white. MiG-23s are all grey.

Despite that Ukrainian Su-27s came from the same Soviet Union stock as the
RuAF Su-27s, they have a green radome.

Vietnamese Su-27s have white noses, which makes me suspect they're former Soviet Union. Venenzuela's Su-30MK2 has a white radome.

Indonesia's Su-27SK have a grey radome, and so are the Su-30MK they got.

India's Su-30K and Su-30MKI both have grey radomes.

China's J-11B has a black radome much like its J-10s. Newer J-8IIs have the black radome but older models have a green radome. The newer JH-7As sport a dark grey radome but older JH-7s use a green one. But for some reason, China's Su-30MK2 have a white radome while the MKKs have grey ones. All J-7s use a green radome, including the newest ones.

Sometimes I'm really not sure of any answers as to why the color is so. Is it bcause of preference? Is it because of the material? The radomes used in the PLAAF, including the Flankers, look unpainted.

Even China's Su-27SKs and J-11s have some color differences alone. The nose of the Russian made SKs tend to have a darker colored grey radome, while the J-11s tend to have a lighter grey one. Yet the SKs have a lighter toned body, while many of the J-11s have a darker tone. Sometimes these planes are all in the same unit, and when lined up in a row, the color differences of the body and the radome stand out, make it easier to tell the J-11 from the Russian made SK.

Even the J-11s alone have some color difference. Many of the J-11s have a moderate grey tone that is matched to the 3rd batch of Su-27UBKs. Although Russian made, the grey tone of this batch is slightly darker than the two previous batches.

The traditional PLAAF color had been previously during the J-6 era, as aluminum unpainted. Then the PLAN, J-7s and J-8s went white, although I could not recall any J-6 at all that was white. In more modern times, the J-7s and J-8s are now grey, though many of the older planes have yet to be repainted. Many of the J-6s and some of the J-7s on the other hand, went to a ground and green colored camouflage. Q-5s were either white or camoflaged, but lately all are deep olive green, suggesting a strong low altitude mission role.

 

[Kilo636]

Re: New JF-17/FC-1 thread

I wouldn't discount LCA. Conceptually speaking, you can argue that it is even more modern than J-10 with its tailless delta and 45% composite usage. And I'm sure that the number mentionned there will improve as they do more tests. This is pretty much their first major fighter project, so it's not surprising that they haven't been able to deliver it online.

Gripen,Euro fighter,Rafale and J-10 share similar canard,delta wind design...

And they are some of the most foremost fighter plane in the world...

 

[crobato]

Re: New JF-17/FC-1 thread

But these are supported by canards, so the flight dynamics are fundamentally different.

There are reasons why a non augmented tailess delta is a bad design, compared to a tailed delta, aka Fishbed, or with a canard.

The most important maneuver a plane does is to push its nose up. If the plane has rolled sideways, pushing the nose up means its pushing the nose to the side, and the plane is turning.

1. In a conventional plane, you have to push down the tail to move the nose up. That's negative lift on the tail, which has to be countered by the lift in the main wings, which creates the force to turn the plane around.

Now at least you understand that part.

2. But in a tail less delta, what's going to push the tail down? Yup, the main wing itself using elevons. That means your main wing isn't making as much lift as it is supposed to be. In a conventional tailed plane, elevators are trimmed down, while the ailerons on the main wing are trimmed up. In a tailless delta, the elevons---surfaces that combine the function of both elevators and elevons---are trimmed down.

2A. The advantage of having a tail is that you can move the elevators further backward from the plane's center, which acts like a fulcrum of lever movement. The farther it goes, the greater is the control authority of the elevators, which is why in planes like the MiG-21 all the way to the F-22 try to extend their elevators as far back as possible. The more authority you can produce by the least deflection of the elevators, the less drag the elevators make and the less energy you bleed.

However, if the downward torque is being applied much closer to the plane's center, as in the case of a tailless delta, you cannot produce as much lever torque as a tailed design. This means more deflection on part of the elevons, which means more drag and energy you bleed into the turns.

3. Now where does canards come in? Instead of forcing down the tail to push the nose up, why not just lift the nose up instead directly? This is much faster. The canards also contribute to positive lift, lowering the wing loading and increasing lift, so the plane can climb or turn around faster. They enjoy an uniterrupted airstream, which increases their pitch authority, a smaller canard can do what a bigger elevator or elevon must equal. Due to the strong pitch authority, you don't need to trim or deflect the angle of the control surfaces, reducing drag and energy loss.

3A. Now there are close coupled canards like the J-10 and Rafale, and open ones like the Typhoon. The farther the canard is from the center of the plane, the greater the pitching authority. With the canard on the nose of the Typhoon, the pitch must high indeed. The more pitching authority you have, the less you need to deflect the canard and the less drag results.

3b. However the close coupled canard, while not proving the same level of pitching authority, has their own unique benefit. The canards also act like a LERX and generate energizing vortices on top of the body at high AoA. These vortices stabilize the aircraft at high AoA, maintaining control. Vortice generation and management is crucial to high AoA behavior.

4. It can be said the bent in the LCA's wing can be used for vortice generation, like a LERX. But without canards or a tailed elevator, this is still far from an optimum maneuvering solution.

5. Pure tailless deltas like the Mirage 2000 still manage great maneuverbility due to a large wing area and the resultant low wing loading. However, once these things go into a turn, they bleed energy quickly, and every Viper pilot knows how to take advantage against that.

 

[fishhead]

Re: New JF-17/FC-1 thread

Good explaination, crobato

The "tailless delta" design has its advantage. The aircraft structure is simple, the flight control is simple, more stealth, carrying more fuel.... If it's really good, everybody will go that way. Unfortunately, its drawback overweights it advantage.

Considering that LCA conducted its test with the world best medium thrust engine, it doesn't have overweight problem, hasn't weaponized, the spent time and achieved performance really show the probem of this design. This kind of design totally depends on its wings to manuver, and the wings are used to carry weapons as well. To do flight control, it needs a big elevon, but the big elevon will interact with weapons hang under the wing in the high speed.

So we've seen enough problem of LCA flight test, the biggest one hasn't come until Indian starts to weaponized the bird.

 

[Indianfighter]

Re: New JF-17/FC-1 thread

That is a ceiling of only 49,000 feet-very low. Speed and low Gs point to a low performance aircraft.

Mr. pshamim, sir the altitude of 49,000 ft. along with the speed of 1.4M and 20 deg. AoA is the envelop that has been achieved till now.

As of the writing of the brochure, LCA had completed 580 test flights. Currently this figure is over 630 flights (including many flights at Aero-India 2007). It is certain that the full-flight envelop will be reached.

The projected flight envelop is :

50,000 feet altitude.
+9/-3.5 G
1.6M

I do not know the projected max. AoA, but you may refer to

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. As is the case with all delta aicraft, its performance should be high.

Crobato, the LCA did not need canards, as was proven in wind-tunnel tests of the Naval LCA (you may refer to

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). The bent on its forward wings (called cranks) provides sufficient lift on account of the vortices generated.
As I've mentioned earlier in another thread, canards can increase weight, increase forward-drag and increase RCS.

But different aircraft have different requirements and so Grippen, J-10 and Rafale have canards whereas the LCA doesn't.
Instead, the LCA has a compounded and cranked wing design. These twin features are absent in the Mirage-2000, which is only an ordinary delta design.

fishhead, I agree that a tail-less delta LCA has fewer control surfaces, but that was not a motivation for its design.
If you see all fighter designs that were initiated in that time ,all of them have this design namely Gripen, J-10, Typhoon and Rafale. So it was a prevalent trend to design delta-winged machines because the need for high speed attack might have been foreseen.

 

[fishhead]

Re: New JF-17/FC-1 thread

You look at the flap on the LCA wing, it's huge, which is understandable for the control demand.

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Then you look at the missle hung under the wing, the position will be a problem when the flap trimed down.

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I am waiting with the great interest to see how Indian engineer will handle it.

 

[Indianfighter]

Re: New JF-17/FC-1 thread

The target AoA of the LCA is 25-26 degrees (please refer to the article I gave before, "An Approach to high AoA testing of LCA"). With rudder augmentation, it can be upto 30 degrees.

According to the same article, the currently achieved AoA is 22 deg.

It must be said that AoA per se is not the defining parameter for turn-rates, because a delta-wing machine can achieve the same turn-rate with a much lesser AoA. So, if a conventional tailed machine has an AoA of 35-40 degrees, it will be equal to the turn-rate of a delta-fighter which has an AoA of only 25-30 degrees.

The following technical paper details the LCA's Flight Control Systems with complete schematics and architecture (refer from page 9 onwards) :

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Those with an aeronautical engg. background can refer to this paper :

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[planeman]

Re: New JF-17/FC-1 thread

These twin features are absent in the Mirage-2000, which is only an ordinary delta design.

No, it's a compound delta with fixed forward surfaces:

This overcame some of the high AOA and stall problems of the Mirage III series.

 

[crobato]

Re: New JF-17/FC-1 thread

indianfighter,

You are assuming that canards are just for vortex formation. It is a lot more than that. Cranks and LERX are not functional lifting surfaces, canards are. Canards add to the total wing area of the aircraft, which is why when wing loads are measured with canard deltas, its wing plus canard area, not wing itself.

Canards create a pitching movement, cranks don't. The fact that you still have an elevon means you have to push the tail down (create negative lift) in order to push the nose up. This means you lose lift in a turn. Depressing the elevons also create drag, which means you lose speed.

Since the elevons are closer to the center of fulcrum position of the aircraft, this means higher authority is needed, and that means you have to depress the angle of the elevons further, creating more drag. For a tailed aircraft to achieve the same rate of turn, you don't have to deflect the elevator as much, which is less drag and more speed. The canard provide the optimum, because control authority from the forward position is the highest, so you need the least bit trim from the control surfaces, which means the least drag, and the faster you can turn.

It must be said that AoA per se is not the defining parameter for turn-rates, because a delta-wing machine can achieve the same turn-rate with a much lesser AoA. So, if a conventional tailed machine has an AoA of 35-40 degrees, it will be equal to the turn-rate of a delta-fighter which has an AoA of only 25-30 degrees.

This assumes you are not bleeding speed from the turn, and this is certainly not true of tailless deltas. Even the Mirage 2000 is notorious for bleeding speed quickly, one or two quick turns and that's it, it becomes slow enough to be vulnerable, and you would need to lit your ABs or go into a beam maneuver and dive to recover that energy.

On the other hand, given the same turn radius, a conventional tailed fighter or a canard delta will turn faster due to less drag, with the canard delta turning the fastest. So even at lower AoAs, the advantage still goes to the other configurations.

Tailed and canard planes also offer other perks too, like having more control surfaces, instead of a control surface that does double duty (elevons).

Because of drag issues, a tailless delta turning on the outside using a lower AoA, will not turn as fast as a tailed fighter turning inside on a smaller circle with high AoA. There is a reason the F-18 Hornets and the Flankers do what they do. You actually have a better case of turning outside with a tailed jet lke an F-16 or with a canard delta like the Typhoon.

 

[kursed]

Re: New JF-17/FC-1 thread

KAMRA: Air Chief Marshal Tanveer Mehmood has said the issue involving the engine of JF-17 Thunder aircraft has been resolved amicably and there is no immediate threat vis-a-vis availability of the Russian RD-93 engines for the aircraft.

While addressing the queries of media at the Pakistan Aeronautical Complex (PAC) in the first ‘Meet the Press’ here Friday, the Air chief seemed confident that the joint venture would never be sabotaged, regarding the controversy attached to the supply of engines.

Admitting India had been trying hard to dash the future prospects of the JF-17 Thunder, Tanveer made it clear that the Chinese authorities had given concrete assurances after having sorted the issue with the Russian counterparts. He maintained China was responsible for the supply of engines for it had entered into an agreement with the Russian firm, manufacturing the RD-93 engines.

Asked if Pakistan and China were looking for alternatives, he said such an initiative could be fruitful for both the producers as the project envisaged large number of combat aircraft production in the years to come. As aircrafts needed new engines twice in its operational service, the production of new engine could help smooth supply, besides making the project more cost-effective.

Asked about his fears vis-a-vis the possibility of negative Russian intervention, Tanveer said: “Yes, it’s a Russian engine. And yes, the notion about the Indian endeavours is partly true. But one must understand that the engine is a contract between the Chinese and the Russian governments. We are not a party to that contract. Subsequently, the re-exporting of these engines to Pakistan is the issue between Pakistan and the Chinese industry. They have ensured us there would be no impediment in this regard. We hope this engine issue will cease to be an issue.”

Asked about the cost of a JF-17, the Air chief said the cost per piece was almost half of any of the compatible fourth generation fighter jet in the market. He said the advanced platforms cost anything between $45 million to $150 million. He believed the potential of the aircraft was much greater when compared to the cost on one unit.

Elaborating on the JF-17’s induction schedule, the Air chief said the PAF had acquired two planes on March 2. These two aircraft sailed the Pakistan’s skies on March 10 for the first time. He said the biggest challenge after assembling the jets was to make the fighter’s first public appearance on March 23 a great success.

Tanveer hoped the PAF would acquire six of these planes by the end of this year. He added Pakistan intended to go into formal production of Thunders at the PAC Kamra next year, whereby achieving the objective of 50 per cent share in the manufacturing of these platforms in Pakistan. He said the PAF looked forward to the production of 15 new Thunders produced in Pakistan next year.

The Air chief was sure the PAF would replace all its aging fleets of Mirages, F-7s (advanced versions of Mig-21) and A-5s (fighter-bombers) by 2015. He believed the PAF would acquire around 200 Thunders till that time, depending on the pocket of the country and the desire for the replacement.

He said the PAC would produce between 25 to 30 Thunders every year if required. He said Pakistan had the resources for financing 150 aircraft initially. Speaking high of the platform’s potential, Tanveer made no bones in claiming the Thunder would be a lethal weapon in the PAF’s inventory in the years to come. Believing it to be slightly superior to the existing fleet of F-16s (till refurbished by the US under the new contract), the Air Chief was optimistic about the JF-17’s capability even if the PAF did or didn’t have the Block 50-52 F-16s.

He said the PAF had a high-tech, all weather, day and night multi-role platform which would be able to carry a vast range of air-to-air, air-to-ground and maritime payload. He didn’t deny the fighter would have the nuclear delivery capability.

For the air-to-air combat, Tanveer said the platform would have a reasonable and sophisticated Beyond Visual Range (BVR) tracking and delivery system, fifth generation short-range missile system and state-of-the art avionics to support the weapon delivery. He said the Thunder would have a wide-range of standoff weaponry for air-to-ground missions, besides having complete prowess to support the Pakistan Navy in maritime operations.

Asked about the PAF’s plan to induct the Chinese J-10 in the fleet, he said the air force looked forward to it. However, he maintained that the proposals to this effect were expected to be finalised by the mid of the next year. J-10, at present, didn’t have the configuration required by the PAF. He said the PAF people had already demanded a better radar and avionics on the J-10, and the proposals to this effect were expected to be finalised by the mid of the next year.

Speaking about the induction of the latest versions of F-16 Fighting Falcons in the PAF’s inventory, the Air Chief Marshal was hopeful the induction of used Block-50-52 state-of-the-art fighters would start this year and the process might be completed in 12 to 18 month’ time.

“The F-16s are believed to be delivered in the first and second quarter of 2010. As for the used aircrafts, those are expected to be delivered in the next 12-18 months, depending on the availability of the aircraft.”

He said the PAF planned to buy 18 new and 24 used F-16s, besides going for mid-life upgrades on the existing fleet. He believed the PAF would learn a great deal about the latest avionics and advanced weapon systems after acquiring the latest Fighting Falcons. He said the training to be provided to the PAF personnel in different departments by the US on the new F-16s would go a long way in improving the vision of the PAF engineers and pilots, which would be helpful in taking a leap forward in understanding the advanced air warfare.

He also explained how the PAF was working in advance on the air-to-air refueling project as the Thunders would become the first platforms, having this capability. He said the pilots and the air and ground crew was already at work to make the project a success.

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