Why can't Private Sector Make CFT?

[khanasifm]

http://navy-matters.blogspot.com/2016/08/super-hornet-conformal-fuel-tanks.html?m=1

We knew it was essentially a zero-drag configuration and, although there was no content in the tanks, we could measure drag through fuel flow. We actually saw a little better performance, as it improves transonic transition.” (1)

“The CFTs add no drag to the aircraft at subsonic speed; at transonic or supersonic speeds they produce less drag than a centerline fuel tank …” (4)

Northrop says the prototype units went from “napkin to first flight” in just 10 months. “The effort began in 2010 with low-level trade study work until 2012, when the decision was made to make a prototype happen quickly,” says Walke. Following a go-ahead in September 2012, the tank design was completed in January 2013, assembly began in May, delivery started in early July and flight tests on a leased F/A-18 were underway in August.” (1)

 

[MastanKhan]

Hi,

It is not that the Paf cannot make CFT's---the problem is with the defensive posture and mindset---.

If the posture is to protect the local assets without getting out of the comfort zone---then why invest in long range flying---.

 

[AZADPAKISTAN2009]

To me it just sounds Pakistan has a Timid mindset of operation across 300km-400km range and they feel if they went out of this "self Imposed" envelope they will not be best friend with rest of world

While rest of the world airforce are always boasting about ability to go across half the plenet with their planes and missiles

Sooner or Later Pakistan has to start acting like a Nuclear powered Nation

We need to send a strong message to Israel the weapon they are sending to India are not going to be igored from our side there will be reprecussions

 

[GriffinsRule]

Was F-6 an airplane with advanced FBW? And the fact that almost no other pictures besides the one you posted (probably by Peter Stienmann in the 80s) have floated around, its suffice to say it wasnt a very successful adaptation, otherwise we would have seen it in widespread service.

For argument's sake even if you can weld together say a CFT for JF-17s, who is actually going to be rewritting and testing of the software codes for the FBW to work properly in all regimes of flight? Will the private sector get a hold of a PAF plane to do years worth of testing (as unlike the West where this stuff is tested and developed by the manufacturers and not the air forces).

As far as older aircraft are concerned, that have less then a decade of service left, its not even worth spending energy or resources towards them. Focus should be towards developing newer generation of aircraft with better capability.

 

[Raider 21]

Was F-6 an airplane with advanced FBW? And the fact that almost no other pictures besides the one you posted (probably by Peter Stienmann in the 80s) have floated around, its suffice to say it wasnt a very successful adaptation, otherwise we would have seen it in widespread service.

For argument's sake even if you can weld together say a CFT for JF-17s, who is actually going to be rewritting and testing of the software codes for the FBW to work properly in all regimes of flight? Will the private sector get a hold of a PAF plane to do years worth of testing (as unlike the West where this stuff is tested and developed by the manufacturers and not the air forces).

As far as older aircraft are concerned, that have less then a decade of service left, its not even worth spending energy or resources towards them. Focus should be towards developing newer generation of aircraft with better capability.

A mixed team though.... for example the USAF, US Navy and US Marine Corps have dedicated test squadrons that work in conjunction with aerospace manufacturers and other defence contractors. Over there they develop aircraft. In Pakistan there's more hype.....they will learn either later or sooner that the private sector needs to be involved in the aerospace defence sector.....JF-17 songs will only remain songs and progress will be slow if the project is still under the air force. The engineers go on rotations based on their service ranks and postings....civilian engineers can stay longer on projects thus more dedication towards R&D and testing.

 

[Advocate Pakistan]

Just a tank , attached to body , which deflects the high winds with smooth curved surface not rocket science

Here is the cross-section of a simple drop tank of F-5 Tiger II,

As you can see, there's associated plumbing, suction and control systems. Splash dampening plates.
The internal systems on the tank can be made with a bit of research in fluid dynamics. The rest can be sought out by limited external support regarding aerodynamics. If not from China and Turkey than from SAAB, BAE etc.

 

[war&peace]

Of course....very simple. No need to know the effect of stability and control on the aircraft, not to mention the varying maneuvering loads on the new configuration on the airframe. Just add some muscle fuel tanks on the body.

It can affect location of the combined centre of gravity especially if the fuel intake to the engine creates a differential then the CG can shift laterally so that needs to be considered and evaluated. If it is small shift then the flight computer can handle it with ease but it may need some programming. However that needs to be thoroughly document. Also the fuel sloshing creates instantaneous shifts in CG and give rise to laterally or axial forces so their rate and magnitude need to be accounted for as well.

In addition, it needs to be protected from fire. Structurally rigid enough but not too heavy since it is an airplane and added weight increases the induced drag coefficient which can be significant.

​

(Note: Drag cannot be accurately calculated with this empirical formula, it needs to be measured through wind tunnel testing)

Though a careful design would rather result in the drag reduction especially in the Mach range of approx. 0.8 to 1.2 aka transonic flow regime.

Then comes the difficulty of manufacturing, producing such aerodynamically conformal surfaces require high end machinery and process.

Here is the cross-section of a simple drop tank of F-5 Tiger II,
View attachment 431297
As you can see, there's associated plumbing, suction and control systems. Splash dampening plates.
The internal systems on the tank can be made with a bit of research in fluid dynamics. The rest can be sought out by limited external support regarding aerodynamics. If not from China and Turkey than from SAAB, BAE etc.

Pakistan does not need any foreign help in designing the fuel tanks at all. Rather they can help. Ra'ad and Babur both have fuel tanks designed by Pakistani scientists and engineers. @MastanKhan you're right.

 

[Raider 21]

It can affect location of the combined centre of gravity especially if the fuel intake to the engine creates a differential then the CG can shift laterally so that needs to be considered and evaluated. If it is small shift then the flight computer can handle it with ease but it may need some programming. However that needs to be thoroughly document. Also the fuel sloshing creates instantaneous shifts CG and give rise to laterally or axial forces so their rate and magnitude need to be accounted for.

In addition, it needs to be protected from fire. Structurally rigid enough but not too heavy so since it an airplane and added weight gives the induced drag coefficient so it can be significant.

View attachment 431320
​

(Note: Drag cannot be accurately calculated with this empirical formula, it needs to be measured through wind tunnel testing)

Though a careful design would rather result in the drag reduction especially in the Mach range of approx. 0.8 to 1.2 aka transition flow regime.

Then comes the difficulty of manufacturing, producing such aerodynamically conformal surfaces require high end machinery and process.



Pakistan does not need any foreign help in designing the fuel tanks at all. Rather they can help. Ra'ad and Babur both have fuel tanks designed by Pakistani scientists and engineers. @MastanKhan you're right.

I'm well aware sir, I was being sarcastic. Thanks for the information anyways. Cheers !!!

 

[khanasifm]

http://m.aviationweek.com/awin/upgrade-fa-18-fuel-tank-gains-ground

in flight tests, pilots reported it flew just like a Super Hornet. It accomplished everything we wanted it to do.

 

[AZADPAKISTAN2009]

Hi,

It is not that the Paf cannot make CFT's---the problem is with the defensive posture and mindset---.

If the posture is to protect the local assets without getting out of the comfort zone---then why invest in long range flying---.

That is true however Pakistan's stance has been quite negative in term of actually making something which is a very simple solution. This CFT enhancement to all our fleet is someting that should have bee planned and done 10-15 years ago , becasue it does not involves great amount of Engineernig. Just a Wind Tunnel and models and army of University students

 

[Raider 21]

That is true however Pakistan's stance has been quite negative in term of actually making something which is a very simple solution. This CFT enhancement to all our fleet is someting that should have bee planned and done 10-15 years ago , becasue it does not involves great amount of Engineernig. Just a Wind Tunnel and models and army of University students

What about flight test engineering, enhancements to a baseline aircraft, chase aircraft, flight test engineers and test pilots (not the typical most experienced pilot in the squadron but one who has an engineering degree with a masters in flight test engineering from a test pilot school).....and the associated telemetry equipment, technical writings, manuals.....it is a long process where the science needs to be mastered first before it becomes an art.

 

[Windjammer]

If it was that simple to add CFTs to any aircraft then the older models of F-16s would be first to adopt them.
You need to change and strengthen the structure as a starters then take other aspects into considerations.
Although back in the 80s, PAF experimented with 'Gondola' tanks on it's F-6s, where it increased the sortie time, it also left the air brake completely redundant.

 

[araz]

Since there are no electronic parts involved apart from 1 mechanical part to eject the CFT from plane before dogfight really should be piece of cake to implement this on our existing plane fleet
so simple

People do this kind of stuff in backyard

This is the crux of your discussion???? I think it is a window into your understanding of the subject.
A.You have opened a thread to discuss an aspect which:
B. you obviously dont understand,
C. with a relaince on the private sector whose capabilities you are blissfully unaware of
D. and a need of which you remain unaware.
Do you realize that even if some genie dropped the secrets into your lap, what in your view will be the need for the PAF. OH WAIT!!!!!!! you are seriously not suggesting that we slap on CFTs on every platform irrespective of whether they have the requisite plumbing for it or not_____ Are you? OK; even if one thinks of CFT for the whole fleet we wont need more than 700 tanks for rougly 350 fighters(A very exaggerated figure.) Who would set up a plant for 700 units and what would they do after their order is completed. Then there is the problem of initiating a second programme for instituting the plumbing for the whole fleet which is going to be another problem. It will need a study to assess the need tostrengthen the wings and body of roughly 350 platforms and these would be different for each platform. So once you realize that you are only going to need CFTs for 50 to 100 JFTs (200 units) as you will find it economically nonviable to convert the whole fleet. So you go back to the company and ask them to set up a plant for 200 units need and spend 1 billion setting up the plant and another 250 million in R&D as the materials would need to be researched only to finf that in the five yrs (again a very conservative estimate!!!) that it takes you to establish industry the Chinese are selling you CFTs at 1/3 to 1/4 the cost at which you will produce them. They can do so as their labour is much cheaper and their infrastructure is much larger and they already have money sunk into the R&D.
So there you are with a product that wont sell a business man who wants to shove a CFT up various orifices because he will not be able to sell them and a work force who have nothing to do?????? REALLY!!!!!!!
Now tell me how good an idea is thatand how easy will it be to convince the private sector to invest in that!!!!
A

Can you educate me a little. These CFTs, are they drop tanks your talking about or the things you see ontop of a F-16 Block 52 wing (on the right and left side)?

Yes When you drop them they take the wings and part of the sides of the plane with them!!! Great thinking AZAD PAKISTAN. It is indeed Maadar pidar Azaad.
A

 

[I S I]

Wow. After plethora of Arm Chair Generals... We now got our first batch of Arm Chair Engineers.
Mashallah

 

[The Diplomat]

Wow. After plethora of Arm Chair Generals... We now got our first batch of Arm Chair Engineers.
Mashallah

Graduate of PDF. I got a first in my degree.