JH-7/JH-7A/JH-7B Thread

[Jeff Head]

I personally see the JH-7A and whatever its upgrade may be in the JH-7B as a strike aircraft pretty much solidly.

Certainly it can (and IMHO should) be armed with air-to-air missiles to protect itself and could include the radar/fire control to allow it to do so out to BVR IMHO. But I think the primary task is going to be as a strike aircraft.

For the PLAN, this would primarily be carrying guided munitions, particularly mid to long range anti-shipping missiles.

For the PLAAF if upgraded properly, I would see it doing a similar role, but probably carrying the whole array of air to ground munitions, from precision guided munitions, to dumb bombs and rocket pods...but only engaging in the latter support role where it made sense from a threat perspective, otherwise being a strike aircraft.

But that's just my own opinion.

 

[SteelBird]

Condolences to the family, loved ones, and friends of the two pilots.

May God rest their souls.

A pilot is a very dangerous job. An former Cambodian fighter pilot who was trained in the USSR told me that when you take off in a fighter plane, you can never be sure if you'll have a chance the land safely.

 

[thunderchief]

T/W based off payload and maximum take-off weight (subtract payload from maximum take-off weight to get loaded weight) should actually be between .9 and 95, so it's actually better than the F-35's T/W, hence I think trashing the JH-7's multi-role potential should be avoided. Same with wing area, if you assume it weighs 20-21 tons loaded, you get a respectable 390 kg/m^2 for take-off.

What limits its multi-role potential is more the lack of a good radar, possible lack of high-G stress design, and lack of aerodynamic focus on air to air combat.

Nope. Calculate T/W ratio of JH-7 when armed with lets say 6 AAMs and compare to F-15E or Flankers. I'm no fan of F-35 but it would definitely outmaneuver JH-7 in close combat, and of course has advantage in BVR. On the other hand, engines are too weak to achieve speeds over 2 Mach, so JH-7 could not emulate Mig-31 and function as interceptor. Therefore, JH-7 simply is not multirole aircraft, it is strike aircraft with secondary self-defense capability. As pointed out, it is relatively cheap and completely indigenous product . It works well for PLANAF, maybe not as well for PLAAF but this is a matter of opinion.

 

[Inst]

I suppose it depends on the calculation, and something looks fishy with the JH-7 numbers.

The F-15E, according to Wikipedia, has a .93 T/W. Using the same algorithm I used to calculate JH-7A T/W, though, which is to take the normal take-off weight, then add 1,000 KG for munitions, I get unity. The JH-7 gets a .91 T/W in this scenario. On the other hand, the JH-7 has a much better wing-loading than the F-15E, with ~390 kg/m^2 vs 463 kg/m^2, but the F-15E has significant body lift that the JH-7 likely lacks.

The other troubling thing is that the F-15E, with loaded weight, has apparently about 12,000 KG worth of fuel, while the JH-7A has only 5,000 KG worth of fuel, while the JH-7A is longer and has about the same empty weight. Something is wrong with either the combat radius or the stated payload; what's likely is that stated combat radius is only with drop tanks, or that certain JH-7A hardpoints are fuel-tanks only.

 

[kwaigonegin]

I suppose it depends on the calculation, and something looks fishy with the JH-7 numbers.

The F-15E, according to Wikipedia, has a .93 T/W. Using the same algorithm I used to calculate JH-7A T/W, though, which is to take the normal take-off weight, then add 1,000 KG for munitions, I get unity. The JH-7 gets a .91 T/W in this scenario. On the other hand, the JH-7 has a much better wing-loading than the F-15E, with ~390 kg/m^2 vs 463 kg/m^2, but the F-15E has significant body lift that the JH-7 likely lacks.

The other troubling thing is that the F-15E, with loaded weight, has apparently about 12,000 KG worth of fuel, while the JH-7A has only 5,000 KG worth of fuel, while the JH-7A is longer and has about the same empty weight. Something is wrong with either the combat radius or the stated payload; what's likely is that stated combat radius is only with drop tanks, or that certain JH-7A hardpoints are fuel-tanks only.

You forgot to take into account fuel consumption. How is the F100-PW-220's thirst compared to the modified RR Spey engines?

 

[thunderchief]

I suppose it depends on the calculation, and something looks fishy with the JH-7 numbers.

The F-15E, according to Wikipedia, has a .93 T/W. Using the same algorithm I used to calculate JH-7A T/W, though, which is to take the normal take-off weight, then add 1,000 KG for munitions, I get unity. The JH-7 gets a .91 T/W in this scenario. On the other hand, the JH-7 has a much better wing-loading than the F-15E, with ~390 kg/m^2 vs 463 kg/m^2, but the F-15E has significant body lift that the JH-7 likely lacks.

The other troubling thing is that the F-15E, with loaded weight, has apparently about 12,000 KG worth of fuel, while the JH-7A has only 5,000 KG worth of fuel, while the JH-7A is longer and has about the same empty weight. Something is wrong with either the combat radius or the stated payload; what's likely is that stated combat radius is only with drop tanks, or that certain JH-7A hardpoints are fuel-tanks only.

My suggestion, use empty weight and then add about the same quantity of fuel&weapons . As you can see, it's the engines that make difference. Every plane is built around its engines, power you have available forces you to make certain compromises.

 

[Inst]

My suggestion, use empty weight and then add about the same quantity of fuel&weapons . As you can see, it's the engines that make difference. Every plane is built around its engines, power you have available forces you to make certain compromises.

I disagree; different aircraft are designed for different ranges and consequently their fuel capacity will vary. That mechanism won't work, because to get the same fuel capacity on different planes, you may need to pack them with fuel tanks, and that subtracts from payload. Besides that, aircraft are designed to different payload stresses, because it is obviously going to be stressful for the airframe to hang missiles off its pylons.

That said, I still think that the JH-7A is potentially a multi-role plane provided that it's provided with proper avionics. It will likely not fly as well as an F-15E, and the J-11s / Su-30s will perform better on intercept and air superiority missions, but it can still get to the destination and launch AAMs.

 

[kwaigonegin]

I disagree; different aircraft are designed for different ranges and consequently their fuel capacity will vary. That mechanism won't work, because to get the same fuel capacity on different planes, you may need to pack them with fuel tanks, and that subtracts from payload. Besides that, aircraft are designed to different payload stresses, because it is obviously going to be stressful for the airframe to hang missiles off its pylons.

That said, I still think that the JH-7A is potentially a multi-role plane provided that it's provided with proper avionics. It will likely not fly as well as an F-15E, and the J-11s / Su-30s will perform better on intercept and air superiority missions, but it can still get to the destination and launch AAMs.

you bascially just answered your own question..every aircraft can technically be multirole however unless you have lost all your AS fighters in the 'first days of war' scenario it would be foolhardy to send a JH-7 against a dedicated air superiority fighter. A JH-7's primary role is ASM with fighter escorts like J-10A etc is needed. Secondary would be anything else.

 

[thunderchief]

I disagree; different aircraft are designed for different ranges and consequently their fuel capacity will vary. That mechanism won't work, because to get the same fuel capacity on different planes, you may need to pack them with fuel tanks, and that subtracts from payload. Besides that, aircraft are designed to different payload stresses, because it is obviously going to be stressful for the airframe to hang missiles off its pylons.

When entering air combat fighters usually jettison external fuel tanks and sometimes even dump internal fuel to lighten themselves. Then they build up speed&height (i.e energy) to achieve advantage over opponent. During air combat, they manoeuvre and lose that energy . In both cases better engine is an asset, because what engine really does is conversion of chemical energy from fuel to kinetic and potential energy (aforementioned speed and height ).

That said, I still think that the JH-7A is potentially a multi-role plane provided that it's provided with proper avionics. It will likely not fly as well as an F-15E, and the J-11s / Su-30s will perform better on intercept and air superiority missions, but it can still get to the destination and launch AAMs.

There is no doubt JH-7A could do hit&run attacks while avoiding close combat. But in that role even older 3rd generation fighters like Mig-23, Kfir or J-8 are better simply because they are faster (with upgraded avionics of course ).

 

[Blackstone]

That said, I still think that the JH-7A is potentially a multi-role plane provided that it's provided with proper avionics. It will likely not fly as well as an F-15E, and the J-11s / Su-30s will perform better on intercept and air superiority missions, but it can still get to the destination and launch AAMs.

China has better multi-role solutions than the JH-7A, and the cost/benefit ratio of upgrading avionics might be too high.