JF-17 Thunder Multirole Fighter [Thread 4]

[Munir]

The Phantom was an horrible airfighter. It only could use thrust as an advantage and after that it hat to bug out. So going vertical and then move in for missile shot. At that time it had no gun because it was seen as outdated. Later after huge losses they added the Vulcan but there was not much else to do then add it under the nose and increase some nose volume. So it did win thanks to good training and thrust. And even then... The opponent was very weak (it had no top training and farmers were good enough to repair, arm and fight). The Phantom was a superb bomb truck but had zero agility. No wonder that is was called the flying brickstone.

 

[Argus Panoptes]

The differences in agility were due to other design factors thats the point

Of course, I have said that all along. But, please keep in mind that having the advantage of better thrust on top of fairly equally agile platforms is better still. That is also my point when comparing the JF-17 with others in its class.

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PS to previous post: The F-5 was a dud, the only thing in its favor being speed. The same basic airframe with the F-404 engine is a great example of just how important a boost to performance and agility a good T:W ratio provides, other things being relatively equal. Thank you for reminding me of that example to prove my point. (Another example is the Mirage III/V and Kfir.)

 

[Chrome9]

The Phantom had a T:W ratio of about 0.85, while the Fishbed was very close at 0.84, not that different. The differences in agility were due to other design factors, mostly the design of the wings. The real issues in the Vietnam war were the type of ordnance carried by US planes, and their lack of training for close dogfights, and not the planes as much.

(The T:W ratio of the JF-17 is substantially less than 1, while that of the F-16 is well above it.)

I don't agree with the last line. Real T:W will not be revealed, so unless you know something the rest of the public doesn't you can't precisely quantify and compare the T:W of the aforementioned aircraft.

 

[Argus Panoptes]

I don't agree with the last line. Real T:W will not be revealed, so unless you know something the rest of the public doesn't you can't precisely quantify and compare the T:W of the aforementioned aircraft.

I respect your right to disagree, but the T:W ratio of the JF-17 with its present engine is well below 1, likely in the 0.82 to 0.85 range.

(I do not claim, or in fact know anything that is not public. I am just a student, and a pretty nalaiq one at that.)

 

[Manticore]

@sancho had messaged me a formula a year back for thrust to wt ratio and applied it to both jft and gripen.... and jft wasnt that far down in this criteria. The difference was when you compared dry thrust only

TWRs
..................
....
Afaik a good way to calculate the TWR is:

Thrust in kN / G (Earth surface gravitational field strength of 9.807 m/s²)

=> / emptyweight + internal fuel => TWR


With the figures you gave in your comparision of JF 17 and Gripen, it would be like this:

JF 17 B1:

84,5/ 9,8 = 8622

6411+2300 = 8711

8622 / 8711 = 0.99 (rounded to the 2nd digit)


If we take the specs from PAC Kamra site, we have to take 14520lb (6586Kg) emptyweight to account, which changes the results to 0.97 (rounded to the 2nd digit)


Same way for Gripen C:

80,5/ 9,8 = 8214

6800+2270 = 9070

8214 / 9070 = 0.91 (rounded to the 2nd digit)


Short TWR ranking (clean with AB thrust):

1. F16 B52 - 1.11
2. JF 17 B1 - 0.97 to 99
3. LCA Mk1 - 0.96
4. Gripen C - 0.91
5. J10A - 0.88

..............

.....

 

[Thorough Pro]

Really? Are you serious?

The Phantom was not even designed to dogfight. For that reason it had missile armament and no guns. Similarly the USAF had abandoned most tactics of dogfighting in their training.

 

[Manticore]

The Phantom was not even designed to dogfight. For that reason it had missile armament and no guns. Similarly the USAF had abandoned most tactics of dogfighting in their training.

the early missiles were not very effective and usaf had to mount a gun in light of heavy casualties in the vietnam war ... however this topic would derail the thread

 

[Thorough Pro]

A jet fighters T/W ratio is calculated as follows,

Dry thrust in lbf or kgf
divided by Aircraft weight with full internal fuel in lb or kg respectively

in case of JF-17 these figures are

Dry thrust = 11,100 lbs
Combat thrust = 19,200 lbs
Empty weight = 14,520 lbs
Weight with internal fuel = 19,620 lbs
Max take-off weight = 27,300 lbs

T/W (with full internal fuel, not a useable measure in my opinion) = (11,100/19,620) = 0.56
T/W (with max take-off weight, more realistic and practical in my opinion ) = (11,100/27,300) = 0.40

T/W (with military thrust and full internal fuel) = (19,200/19,620) = 0.97
T/W (with military thrust and max take off weight) (19,200/27,300) = 0.70

I took the specs from this pic displayed at Ideas 2012.

@sancho messaged me a formula for thrust to wt ratio and applied it to both jft and gripen.... and jft wasnt that far down in this criteria. The difference was when you compared dry thrust

 

[Capt.Popeye]

Really? Are you serious?

Yes I am. That was a peculiar phenomenon of THAT TIME. Then John Boyd came back as an evangelist for both dogfighting and the dogfighter. But even his evangelical task was not easy in the USAF of that time.
As @Munir above has mentioned; the new-fangled AAMs were seen as "magic weapons" along with AI Radars where USA was well ahead of anybody else. So that was considered to be adequate. Hence aircraft were designed around these ideas.
The concept was just "Sight, Shoot and Scoot". If the aircraft had changed in their capabilities, the tactics would correspondingly change. Which is what happened.

Curiously, even the Phantom's adversary, the MiG-21 initially did not possess gun armament, because of a similar belief in AAMs on the other side. When missiles on both sides were found to be inadequate, the serious rethink was embarked on. The MiGs designers then added on a podded 23mm cannon. And the fact that the MiG was more agile was just a bonus. While the Phantom was not intended to be.

Even @ANTIBODY has added some valuable inputs about this.

So: aircraft designs, aircraft capabilities and airfighting tactics impacted each other in circular fashion.

 

[Thorough Pro]

Read gambit's response.

Yes I am. That was a peculiar phenomenon of THAT TIME.

 

[Capt.Popeye]

Read gambit's response.

Oh yes, I did. It is just an enunciation of the principles and objectives of the ACM training in USAF. I stand by my views.

 

[Bratva]

 

[gambit]

Oh yes, I did. It is just an enunciation of the principles and objectives of the ACM training in USAF. I stand by my views.

If you mean that the USAF somewhat 'abandoned' ACM training at the time of the misguided decision to omit the gun from the fighter aircraft, you have a partial point. Rockets and missiles from fighters are not new. But the belief that somehow a missile is statistically lethal enough for fighter pilots to be nothing more than 'pilot' and leave the 'fighter' to the missile was new. Enough among the USAF's leadership did buy into that belief and they concurred to the manufacturing decision to delete the gun from the fighter aircraft. ACM training did partially became irrelevant in doctrine and was slowly trickling down to the training units. However, the losses in Vietnam quickly resurrected the institutional memory of ACM and it was evident with Operation Bolo where gun-less Phantoms using inaccurate missiles took out half of the North Vietnamese MIG-21s and grounded the other half for months.

 

[Capt.Popeye]

If you mean that the USAF somewhat 'abandoned' ACM training at the time of the misguided decision to omit the gun from the fighter aircraft, you have a partial point. Rockets and missiles from fighters are not new. But the belief that somehow a missile is statistically lethal enough for fighter pilots to be nothing more than 'pilot' and leave the 'fighter' to the missile was new. Enough among the USAF's leadership did buy into that belief and they concurred to the manufacturing decision to delete the gun from the fighter aircraft. ACM training did partially became irrelevant in doctrine and was slowly trickling down to the training units. However, the losses in Vietnam quickly resurrected the institutional memory of ACM and it was evident with Operation Bolo where gun-less Phantoms using inaccurate missiles took out half of the North Vietnamese MIG-21s and grounded the other half for months.

The attitude prevailing in the USAF AT THAT TIME was the focus of my post. ACM training was not really abandoned, it just changed in the method that was taught and hoped to be executed in combat. Right upto the era of the redoubtable F-86, the USAF saw dogfighting as the essence of ACM.
Now with the (perceived) magic weapon- the AAM; the intention (and method) was somewhat altered to "sight, shoot and scoot". Which seemingly is back again (to a fair extent) in BVR combat.

As I did say earlier:

aircraft designs, aircraft capabilities and airfighting tactics impacted each other in circular fashion.

Source: http://www.defence.pk/forums/jf-17-...ole-fighter-thread-4-a-662.html#ixzz2PJ36plFn

You are correct about "Bolo". That had a number of contributory factors; one major one of which was that Americans could effectively jam the 'Fan-Song' Radars with the VN airforce with E-6 Intruders as well as knock them out with HARMs. The MiGs had very poor AI radar capabilities hence needed GCI to vector in on Bogeys. This was now severely impaired. Plus the 'magic' AAMs on the VN side were worse than the American ones. Not to mention that the Fishbeds had no gun either due to a similarly flawed design philosophy.

 

[TaimiKhan]

Guys, can this discussion with regard to USAF & its training doctrine be taken to some other specific thread as this thread is being derailed even though the discussion seems to be quiet entertaining.