*New J-10 Thread*

crobato said:

It does not sound like there is a lot of expertise in that article.

If you want to compare weights, the best way is to look for other Chinese air examples, because one Chinese plane is likely to be built on the same level of technology as another Chinese plane. Here you can take out national differences in construction.

Look at the FC-1. It is also made by Chengdu. It does not have a lot of composite. But it weighs only 6400kg empty. Do you think the J-10 is a lot bigger than it to justify 9750kg empty? And its not the engine, the RD-93 is only about 100-200kg lighter than AL-31FN at the most. In fact the FC-1 is slightly longer than the F-16.

Comparing the F-16 as a benchmark for weight is FLAWED. Maybe some people don't understand F-16 history. The original F-16As were coming at 7000kg empty. They were quite light, and up to this day, they are still regarded as the most agile and maneuverable variants.

But the planes were also pushed to the limits and used more strenously than the original designers expected. Many planes suffered cracks and other stress symptoms.

So the F-16C is beefed up considerably and in return, the empty weight went up to 8500kg for the PW engine version and 8800kg for the GE engine version. But the same time, the requirements now call for an exhaustive 8,000 flight hour life (some say 12,000 hours), at least before one major overhaul. Although the Russians have a different standard for "overhaul", a Russian plane is about 2000 flight hours (Su-27 as an example) before it commits to the Russian definition of overhaul.

I don't think the J-10 is overbuilt to the same extent as the F-16C. The airframe would probably exceed the Russian service pattern but won't meet the same stringent Western requirements. More like somewhere in between. The standards the Chinese set to themselves seems long enough to last for their purposes, such as we have seen with the J-8II examples. But the Chinese also don't involve in various global cop campaigns the US does, or forsee themselves in bombing genocidal dictators or terrorist harboring countries, so they don't have any reason for the overengineering.

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Prior to the US-Vietnam war it was believed that dog-fighting would be a thing of the past. However the USAF realised that this prediction was seriously flawed after a number of engagements.

Hence the early F-16 was designed as a dog-fighter. Obviously as time
passed the F-16 became more multi-role and hence became heavier.

Service life may thus reflect the increasing requirements on the F-16 and
not the role for which it was originally designed

In the 1980s, USAF requirement for aircraft service life was 4,000-4,500 hours, then estimated at 20 years. But after extensive usage in Iraq war, many aircaft had to undergoe extensive rebuild with structural reinforcement to extend service life. The A-10, for example, received rebuilds in hope to extend is useful service life to 6,000-8,000 hours.

After the Iraq war, USAF's requirement for new combat aircraft's service life is now 8,000 hours, or approx. 20 years of service during peace time. Lockheed stress-test F-22' test-airframe to simulate 8,000 flight hours for certification, then another 8,000-16,000 hours to see when/where airframe components fail. 8,000 hours might sound like a lot, but divided by 20 years, that's barely over 1 hour/day. In war, when you have to provide 24/7 CAP, you'd burn through airframes like pizza in a microwave.

During the 9/11 incident, USAF was called to provide CAP over US cities. They estimated that, to provide effective 24/7 CAP over Washington DC and NYC, it'd require about 75,000 flight hours from fighter aircraft, plus 55,000 flight hours from non-combat aircraft. If the 75,000 flight hours were provided by air national guard's F-16's, they'd burn through the equavalent of 10 x F-16 airframes annually -- and that's just for TWO cities.

Another thing to consider is that the 8,000 hour service life is an "average" for safe operations. Depending on how much abuse/stress you put on the airframe, its service life can vary. Some will last longer, others shorter. Generally speaking, the airframe service life requirement goes up by thousands of hours every generation. The F-5E's airframe, for example, was rated at 3,000 hour service life (prior to major rebuild).

Traditionally Russian combat aircraft are designed for maximum performance, where service life is secondary. They feed their aircraft very high octane fuel and make them fly fast and hard. Consequently, their airframe and engines don't last as long. However it's possible to de-tune the engine to extend aircraft service life. The German MiG-29's were de-tuned and fed lower octane fuel to make them last longer.

Due to customer demands in the export market, the Russians are now working to extend the service life of their aircraft to make them more attractive in life-cycle costs. The first MiG-29A's were designed for 800 flight hours prior to major airframe rebild, and maximum service life of 2,500 hours. Since then, the latest versions have improved to 4,000-6,000 hour service life (MiG-29SMT).

Remember that how long an aircraft last is highly dependent on how it was used. The Boeing 747 is rated at 60,000 hour service life, but it's not designed or expected to pull high-G's to evade missiles and dogfight. If a certain poor African country import J-7's from China and use them mostly for display, where pilots were instructed to "baby" the aircraft, then the airframe will prolly last >4,000 hours easily. But the same aircraft in Chinese fighter academy might not last 2,000 hours.

crobato said:

I think the payload weight of the FC-1 is determined more by its engine power than the stress limitations of the airframe. The FC-1 isn't that small a plane, it looks to me its even slightly longer than an F-16A.

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The above statement is inaccurate. The payload of an aircraft is determined primarily by its structural strength, and to an extent by engine power.

FC-1 has only 7 stations (including 2 wingtip rails), to carry a payload of 3600 or 3800kgs, whereas J-10 has 11 hardpoints to carry much more than that. Thus, J-10's structural strength has to be much more than FC-1, which explains the increase in weight.

Earlier, I was mistaken that FC-1 has slightly less payload than J-10 (3800 kg vs. 4500 kg) and thus FC-1's development appeared futile, but FC-1's total payload(weapons+fuel tanks) is 3800kg but J-10's weapon-load alone is 4500kg.

crobato said:

I think 9750kg empty is way too heavy when compared to the FC-1 at 6400kg. Payload differences, engine differences, even airframe life differences, will that make up a difference of over 3000kg?

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The J-10 is developed closer to specifications of F-16 (11 hardpoints, 8500-9500 kg empty weight). Thus it must be structurally strong which increases empty-weight. FC-1 is like the LCA (7 hardpoints, 4000kg Total payload and 5500-6500 kg empty weight).

J-10 and FC-1 are thus, different classes of aircraft.

crobato said:

That's pretty rigid.

As for the FC-1, just because the PLAAF has yet to adopt it does not mean the PAF has some tough requirements of their own. Or that the FC-1 may also be considering PLAAF requirements just in case, or the PLAAF has given their requirements during the course of the development. Certainly those requirements would be taken into consideration. I think the payload weight of the FC-1 is determined more by its engine power than the stress limitations of the airframe. The FC-1 isn't that small a plane, it looks to me its even slightly longer than an F-16A.

I think 9750kg empty is way too heavy when compared to the FC-1 at 6400kg. Payload differences, engine differences, even airframe life differences, will that make up a difference of over 3000kg?

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Yeah, I agree, but I'm just saying that I don't think flight hour of J-10 is all that low. I'm sure the material used on J-10 is also more expensive than the material used on FC-1, so that would translate to tougher material without additional weight.

PSed I'm guessing?

swimmerXC said:

PSed I'm guessing?

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Yes, as the twin-seater has the typical spine !

Deino

dimensions???

Sczepan said:

dimensions???

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Thanxx for Dimensions but would you like to translate it now ?? not everyone knows chinese here.

Detailed Analysis of the J-10

A guy from another forum wrote the following from this source:

To summarize some some of the major arguments:

* Like any multirole fighter-bomber, the J-10 was developed with a bias towards fulfilling certain roles. Based on the overall dimensions of the airplane, and its projected dry weight, fuel capacity, and payload capacity, the J-10 appears to have been biased in favor of the air-to-ground role rather than the air-to-air role.

* As such, the J-10 is most easily compared to the Block 50/52+ versions of the F-16, rather than to some of the Eurocanard fighters such as the Typhoon or Rafale.

* By virtue of its relatively low wing loading (and canard configuration), the J-10 can be expected to have exceptional instantaneous turn capabilities. Its thrust loading, however, is relatively modest, meaning that most Western fighters would have an advantage in terms of acceleration.

What strikes me about this comparison, is that it is reminiscent of the old MiG-15 / Sabre match-up, or of the advantage that the MiG-21 had over most Western fighters of its day. The J-10 appears to be similarly poised to deliver a painful surprise to any inexperienced pilot who attempts to engage it in a turning manuever, but is vulnerable in other areas of its envelope.

* In the air-to-ground role, the capabilities of the J-10 are expected to be truly impressive. It is projected to possess both a payload capacity, and range that put to shame many similarly sized, or even larger airplanes:

"When measured as a multirole, attack platform rather than as a purely air-to-air fighter, the potential for the J-10 to alter the strategic equation in the Far East should become readily evident. In terms of its maximum payload capability, the J-10 is projected to have a maximum weapons load in excess of 9,500-kg (19,850-lb), when outfitted with bombs and missiles for a short-range attack mission. This compares to a maximum payload of 4,000-kg (8,820-lb) for the similarly sized MiG-29S, or 8,000-kg (17,640-lb) for the much larger Su-30."

Statistics for the J-10 were quoted as follows:

Length ........................ 16.5 m
Height ......................... 6.0 m
Wing Span ..................... 11.3 m
Gross Wing Area ............... 45.5 sq m
Empty Weight .................. 9730 kg
Max Internal Fuel ............. 4470 kg
Max Take-Off Weight .......... 24650 kg
Max Thrust ................... 125.5 kN


For the J-10 to have merited an investigative article of this detail is truly a coming-of-age for the Chinese aviation industry.

J-10 seems to be a bomb truck than air to air. Excellent instantanous turn capability but gets in trouble in the vertical plane (major disadvantage against air superiority aircraft with high trust to weight ratio like the F-15C)

Yes, its been posted before.

And it's wrong in some areas.

Point #1

Weight is too large given comparison to four planes that are best used as a reference to the J-10:

Lavi --- 7,000kg empty. Main plane technology reference to the J-10.
F-16C --- 8,600kg to 8,800kg. This is the plane the J-10's mission appears most molded after. The F-16Cs actually have heavier engines than the J-10, not to mention they carry more equipment and avionics.
FC-1 --- 6400kg empty. This is the plane also made in the same factory and would embody similar construction methods and material. Slightly lower niche but similar mission roles. FC-1 is actually expected to have less composite than the J-10.
J-8II --- 9200kg empty. No way a J-10 weighs more than a last generation Chinese plane with 2 engines, longer length and wingspan, and uses less advanced construction techniques and material.

It should be noted that Chengdu AC is quite advanced in composite construction---it supplies subcontracted composite components to Airbus and Boeing.

Point #2

The KLJ type radar installed on the J-10 is mainly A2A use and shows little PGM development when first introduced. If the PLAAF wanted the J-10 to be a strike bomber, it would have used the JL-10A radar used on the JH-7A, which is genuinely multirole, has PGM and AshM integrated already, and has already been approved for the PLAAF and PLANAF too.

Point #3

J-10s were deployed in regiments that previously flew J-7s or J-7Es. They didn't go to more experienced ground attack units that flew Q-5s. Reports and rumors of exercises indicate J-10s are beating J-11s and Su-30s in mock air combat. The first trials operational unit of the J-10, assigned in the FTTC, is also tasked with the regional air defense of Beijing.

Point #4

No way is a J-10 having more payload than an Su-30MKK.

Point #5

Internal fuel load is quite high, and is not consistent to the observation of J-10s often carrying external fuel tanks.

The conclusion is actually the opposite. The J-10 should be lighter and is more fit for A2A roles, as reflected in the way they are deployed and weapons integrated to it, including the PL-12 active guided missile. A2G abilities are less impressive, but thats why the PLAAF has JH-7As.