Tracking jf-17 information post Zuhai air show

[malikkhawar]

good information post.

 

[Aamir Hussain]

Has anyone noticed the ripple lines on the wing root extensions (Near the air intakes) on the photo put by PAFace? This is unsual for high performance fighter to have these ripple lines due to metal fatigue or extreme stress on that part of the fuselage extension.

One sees these ripple lines on naval craft where the high speed or wind resistance is not that big an issue.

Can anyone comment on my observation?

Thx

 

[Last Hope]

Has anyone noticed the ripple lines on the wing root extensions (Near the air intakes) on the photo put by PAFace? This is unsual for high performance fighter to have these ripple lines due to metal fatigue or extreme stress on that part of the fuselage extension.

One sees these ripple lines on naval craft where the high speed or wind resistance is not that big an issue.

Can anyone comment on my observation?

Thx

Youve got pretty sharp eyes.
Saw that now.

I think that due to excessive use, it is like that.

Waiting for expert comment.

 

[SQ8]

Has anyone noticed the ripple lines on the wing root extensions (Near the air intakes) on the photo put by PAFace? This is unsual for high performance fighter to have these ripple lines due to metal fatigue or extreme stress on that part of the fuselage extension.

One sees these ripple lines on naval craft where the high speed or wind resistance is not that big an issue.

Can anyone comment on my observation?

Thx

High loading on the lerx.. causes these ripples to appear...
The designers have opted to use a thin sheet of metal for the skin.. which is sufficient ..but as you noted..looks bad.
The other solution is to use a thicker sheet..or a honeycomb structure...will stop these visual effects..but is more expensive.

 

[Manticore]

cant be excessive use so early! --- i thought it was an inherent design and i still hope so

 

[Manticore]

i consider that the airshow pics will help the engineers to closely observe the aerodynamics of the plane -- alonge these ripples, the fog trails can be studied aswell for bk2 modifications...

 

[SQ8]

Antibody.. all those studies have already been taken.. trust me on that.
The computational flow dynamics were all done in house..
Hilariously.. they were outsourced by the PAF to an Italian company.. which in turn gave the contract to a Pakistani company .
There are only a few full sized wind tunnels in the world.. we have a few for scale models.. but they only served to partly verify the data done on the software.
The use of materials was at the discretion of the designers and only what was sufficient was chosen..That thin metal will hold against all forces.
It just doesn't stress gracefully as other forms of construction.

 

[Tempest II]

Has anyone noticed the ripple lines on the wing root extensions (Near the air intakes) on the photo put by PAFace? This is unsual for high performance fighter to have these ripple lines due to metal fatigue or extreme stress on that part of the fuselage extension.

One sees these ripple lines on naval craft where the high speed or wind resistance is not that big an issue.

Can anyone comment on my observation?

Thx

Thanks for asking the question. I had seen the ripple and found them"interesting" too.

I agree with Santro - the engineers have studied the design and there is little learning to be had from airshow videos or photos.

Here is another photo - you can just makeout the ripples.

http://dc196.*******.com/img/7mql-AjP/0.45039354505861406/jf17_new_12.jpg

some high def... pics

I will try and answer the question. This is not my subject - but I am recalling my A-Level physics. I believe it is to do with pressure waves or standing waves. The air flowing over the surface can create a standing wave - see this video: YouTube - Standing Wave . This in the wing surface will cause fatigue and could cause the wing to break apart.

Notice that the wave has an even wavelength, and has nodes and antinodes.

Imagine the above on an aircraft wing. The engineers would the design a wing with uneven ripples or with ripples out of phase with the expected standing wave. This will break the created standing wave and avoid vibration!

I remember an experient at school with sand on a vibrating plate - by changing the Hz, we could change the shape of the sand ripples.

Also, living in a poor country, I have travelled on gravel/dust roads a lot. Sometimes the bumbs form very even ripples. As you drive over them as a certain speed, they try to shake your car to bit, i.e. you are driving at their frequency (i.e. you car wheels hit the ripples at the frequency). You address this by changing speed, i.e. try to have the nodes of you car's vibration on the anti-nodes of the road and vice-versa!
Just my thought - I welcome discussion and debate.
Thanks

 

[jagjitnatt]

Has anyone noticed the ripple lines on the wing root extensions (Near the air intakes) on the photo put by PAFace? This is unsual for high performance fighter to have these ripple lines due to metal fatigue or extreme stress on that part of the fuselage extension.

One sees these ripple lines on naval craft where the high speed or wind resistance is not that big an issue.

Can anyone comment on my observation?

Thx

Youve got pretty sharp eyes.
Saw that now.

I think that due to excessive use, it is like that.

Waiting for expert comment.

Good observation skills.

A lot of people wouldn't take my word since I am an Indian, but if I can throw some light on it, I would be glad to.

The ripples you see, are actually ripples. They were caused by wind effects.
Now why they were caused? Because that part you see is just a sheet of metal fixed on a framework.

The strength is not in the sheet of metal, but in the framework. That metal is just to cover the framework, and make it more aerodynamic.

You can see it in the pic below

It won't come off, so don't need to worry, but the aircraft is very new, and still its happening suggests that the metal sheet is thin, and should be replaced with a harder metal, or thicker sheet.

 

[Bossman]

Hi Araz,

We are oceans apart----no mid ranking officer has the authority to clear any information about any material that is not in active service and still there are restraints even if it is in active service.

No Lt or Major or Colonel can talk about and release any info in a public setting---. The guy / officer possibly had a few drinks and spilled it all out in the euphoria of being at zhuhai. Now they are all covering up for it making it sound like nothing happened.

My comments have nothing to do with what has been on the net---and I am disappointed at you for not having the ability to learn what difference the news makes when it comes out of the end-users mouth.

There is no legitimacy in the information that you know or I know or anybody else knows on the net---that is all based upon rumour and speculations.

You may have the pictures and blueprints of the actual workings of the material in question but until and unless the end user don't confirm if it is real or not---till then it is all in the air---and this basic thing that you cannot understand---that is a tragedy for my country and motherland---and you know why---if an educated and brilliant pakistani man like you don't have the understanding and acceptance of this basic fundamental of secrecy and how it works---then truthfully, it is a big loss for the nation.

We are habitually bragging about what we don't have----regardless of understanding as to how many nation are out there trying to string is up and put restarints upon us and they have done that many a times.

Millitary is all about secrecy----all millitary weapons in development are veiled in secrecy---even though there are organisations out there that would want to know the capabilities of the items in question. So---off course there are leaks and info is available---but why are the capabilities of the weapons system being disclosed even before the end user has them in full scale deployment---and even then they don't talk about it.
.

Mastaan has no idea how the military works but he is the self proclaimed authority. He gives example of tanks from other countries. What we we know about Al-KHALID is what we know about the Abrams, the Merkava, or Leapord i.e. weight, gun calibre, engine size etc. etc. what we don't know is configaration of the armour. Do we know if Al Khalid has ceramic plates or other exotic material in its armour and this also what we don't know about other tanks? So if every thing which is released is calculated. There was no surprises in what these mid-level officers said at Zuhai. One way of confirming all this is to keep a track on members of the delegation that visited Zuhai. If one of them broke some secrecy rules we will not see them at any airshow again.They were all very well photographed and we are bound to see them again on other shows. Ours was a very big delegation. Total of 13 display aircraft 3 supporting aircrafts. So the delegation was led by an Air Commadore. The second senior officer was a Wing Cammander who led the JF-17 flight. He was the same office who was at Farnborugh. Eagle Hannan most probably spoke to the Air Cammadore and the Wing Cammander. So keep an eye on them on the net. The next big showing of JF-17 is coming up at the South Africa Air Show and I can bet that the Wing Cammnder will be there with his Jf-17 because he is the senior most Jf17 pilot. There are whole bunch of pictures of him from Kamra airbase where he is based. As far consequences in Pakistan military of of intentionally or unintentionally releasing information I know a number of cases where senior officers, in one case a Major General, were put behind bars simply because of a hint of indisgression let alone proof. I obviously can't give the details. There have been cases where young officers have been court martialed and thrown out of the services for simply writing about what seem like minor military related things on the net. I don't mind Mastaan having view on things, but the problem with him is that he goes about acting as he is the know it all authority on every thing and rest of the folks are dumbasses. And the other problem is that some members on this forum really think that he is such authority on things he opines on.

 

[Aamir Hussain]

High loading on the lerx.. causes these ripples to appear...
The designers have opted to use a thin sheet of metal for the skin.. which is sufficient ..but as you noted..looks bad.
The other solution is to use a thicker sheet..or a honeycomb structure...will stop these visual effects..but is more expensive.

Thanks for the explanation. I agree with you and I think that JFT will pretty soon incorporate honey-combed material like GRP etc. for wing surfaces and wing root extension to save weight and reinforce these areas for smoother airflow. This will also start to improve the thrust to weight ratio.

With what little experience I have got in a close to a lifetime following airplanes and airplane development, this is only the second time I am seeing this type of rippling. The other was on B 52H's and we all know how long they have been flying.

 

[Myth_buster_1]

Mastaan has no idea how the military works but he is the self proclaimed authority. He gives example of tanks from other countries. What we we know about Al-KHALID is what we know about the Abrams, the Merkava, or Leapord i.e. weight, gun calibre, engine size etc. etc. what we don't know is configaration of the armour. Do we know if Al Khalid has ceramic plates or other exotic material in its armour and this also what we don't know about other tanks? So if every thing which is released is calculated. There was no surprises in what these mid-level officers said at Zuhai. One way of confirming all this is to keep a track on members of the delegation that visited Zuhai. If one of them broke some secrecy rules we will not see them at any airshow again.They were all very well photographed and we are bound to see them again on other shows. Ours was a very big delegation. Total of 13 display aircraft 3 supporting aircrafts. So the delegation was led by an Air Commadore. The second senior officer was a Wing Cammander who led the JF-17 flight. He was the same office who was at Farnborugh. Eagle Hannan most probably spoke to the Air Cammadore and the Wing Cammander. So keep an eye on them on the net. The next big showing of JF-17 is coming up at the South Africa Air Show and I can bet that the Wing Cammnder will be there with his Jf-17 because he is the senior most Jf17 pilot. There are whole bunch of pictures of him from Kamra airbase where he is based. As far consequences in Pakistan military of of intentionally or unintentionally releasing information I know a number of cases where senior officers, in one case a Major General, were put behind bars simply because of a hint of indisgression let alone proof. I obviously can't give the details. There have been cases where young officers have been court martialed and thrown out of the services for simply writing about what seem like minor military related things on the net. I don't mind Mastaan having view on things, but the problem with him is that he goes about acting as he is the know it all authority on every thing and rest of the folks are dumbasses. And the other problem is that some members on this forum really think that he is such authority on things he opines on.

You can convey your message without being "personal". He is your father's age and you would not like someone to disrespect your father.

 

[Bossman]

You can convey your message without being "personal". He is your father's age and you would not like someone to disrespect your father.

The internet is age neutral. You are what you write. BTW look what he has written about me in his posts. Doesn't sound like a very mature person to me.

 

[razgriz19]

thats what flares and chaff looks like in an f-16
(btw this is a model)

chaff are in greyish colour and flares are in orange..

and this is gripen...

does anyone see any similar " things" in jf-17??

 

[Last Hope]

thats what flares and chaff looks like in an f-16
(btw this is a model)

chaff are in greyish colour and flares are in orange..

does anyone see any similar " things" in jf-17??

F16 and JF17 have many things in common, as i can say.

From rear view, it is impossible to discriminate!
Also the wings and all the physical body is similar!