Second JF-17B Prototype with more composite material undergoing flight tests

[Armchair]

Hi,

So---it is early 90's and I am selling Lincolns at Beverly hills---. This beautiful older white lady comes looking for a Lincoln Town Car---the size of diamond on her ring finger was almost the size of my thumbnail---.

I started answering her questions and added some technical inforemation as well---.

She retorts---'youngman---speak to me in english---. I got mad---and told her I am speaking in english---and I have a very good accent as well---. She got mad and left---.

I told my boss who was a white guy----he crakced up---say to me---she was not talking about your language skills---talk in english meant---speak in simpler terms that a lay person can understand---and I laughed and laughed and laughed---and still do at my ignorance---.

So---please explain this in a simpler language---sometimes this technical jargon flies over the top of my head---

Let me try to interpret messiach's post - if my English happens to help.

You see the general ungainly shape and comparatively less streamlined look? With the hinges and other bulginess? (Is bulginess a word?). This causes shockwave and boundary layer separation, and post shock stall, at SS (supersonic speed).

Basically this means that there is a lot of drag and other disturbances. Sometimes you open a tap, and the water just flows smoothly, and sometimes you open a tap and it feels like the water is being shat out. You want the former not the latter for good flight characteristics and to lower drag.

Drag is the biggest evil ever for an aeronautical engineer. And drag is an exponential problem when it comes to flight, particularly the higher the speed. This is why the F-35 is such a bad design, btw. With all that gigantic thrust - it all goes to waste and you end up with an ungainly duck of an aircraft. Why? Its drag again.

This is why it is so much easier to design a super-cruising tailless delta. Those stabilizers at the back? They create a giant amount of drag and shock wave issues. Even making an aircraft wet, can drastically increase drag. There are of course, different kinds of drag.

You want to design an aircraft that is like a beautiful, streamlined super-model. Delicately and immaculately chiseled, so that when she is in the shower, the water water just flows beautifully. Well, I'm fasting otherwise I'd give you more of my English.

Additional info: Shock waves are generated in supersonic flight. They are generated at the nose of the aircraft and flow backwards along the length of the aircraft. Managing this shockwave and assorted drag is critical for supersonic flight.

 

[Sinnerman108]

Look, I am your friend when I say this. Try to apply logic to what you have heard. The green color is all over the aircraft, even at the edge of the intakes. It cannot possibly be true that behind each and every green panel, there is fuel storage. Probably there are a few panels that do indicate fuel, and we can probably guess them. But most certainly the vertical tail on Thunder B does not have the required volume.

As for the vertical tail on F-35, there is one single picture on the internet that indicates fuel storage on the vertical tail. I cannot find any written confirmation from authentic sources. You cannot form an informed opinion based on one picture on the internet.

@gambit can you please shed light on the claim that the vertical tail on some version of F-35 stores fuel in it?

Carrying fuel in the tail, would imply that the center of gravity of the plane shifts during flight as fuel is consumed.

 

[gambit]

As for the vertical tail on F-35, there is one single picture on the internet that indicates fuel storage on the vertical tail. I cannot find any written confirmation from authentic sources. You cannot form an informed opinion based on one picture on the internet.

@gambit can you please shed light on the claim that the vertical tail on some version of F-35 stores fuel in it?

Here is an F-111 internal fuel tank locations...

And here is the F-35B...

Notice the difference in labeling.

A 'vent tank' is for fuel expansion at altitude and temperature.

http://www.smartcockpit.com/docs/A320-Fuel.pdf

There is a vent surge tank outboard of the outer tank in each wing.

On the A320, on each wing there is a vent tank.

It is natural to think that any empty space -- volume -- can be exploited, and when it comes to aviation, more fuel is always desired. But when we look at a structure, not every empty space can be exploited.

Fuel quantity is indicated via the capacitive method and this is a fuel quantity probe...

https://liquidmeasurement.com/products/fuel-probes/

All electrical connections to the capacitance probe,...

The device is a tube within a tube. The walls of the two tubes serves as a capacitor and the fuel as the dielectric. The lower the fuel, the smaller this virtual capacitor. The smaller the capacitor, the lesser the fuel. Basic electronics.

The wing tips and the vertical stabilator are simply too small volumes to make an accurate fuel quantity probe. So even though we have an empty space, in practice, if we fill up this empty space, we would NOT have reasonably accurate indication of how much fuel we filled. The probe design would be too short.

So in practice, these small volumes are used as vent tanks. They carry fuel, but are not really calculated as to how much total fuel the jet carries. In flight, engine feed is thru the main fuselage tank(s) and as fuselage tank(s) are consumed, whatever fuel in the vent tanks are depleted anyway, so it is pointless to know how much fuel they actually contains. If we dare to guess, given the consumption rate, maybe a few kms worth of fuel?

 

[MastanKhan]

Let me try to interpret messiach's post - if my English happens to help.

You see the general ungainly shape and comparatively less streamlined look? With the hinges and other bulginess? (Is bulginess a word?). This causes shockwave and boundary layer separation, and post shock stall, at SS (supersonic speed).

Basically this means that there is a lot of drag and other disturbances. Sometimes you open a tap, and the water just flows smoothly, and sometimes you open a tap and it feels like the water is being shat out. You want the former not the latter for good flight characteristics and to lower drag.

Drag is the biggest evil ever for an aeronautical engineer. And drag is an exponential problem when it comes to flight, particularly the higher the speed. This is why the F-35 is such a bad design, btw. With all that gigantic thrust - it all goes to waste and you end up with an ungainly duck of an aircraft. Why? Its drag again.

This is why it is so much easier to design a super-cruising tailless delta. Those stabilizers at the back? They create a giant amount of drag and shock wave issues. Even making an aircraft wet, can drastically increase drag. There are of course, different kinds of drag.

You want to design an aircraft that is like a beautiful, streamlined super-model. Delicately and immaculately chiseled, so that when she is in the shower, the water water just flows beautifully. Well, I'm fasting otherwise I'd give you more of my English.

Additional info: Shock waves are generated in supersonic flight. They are generated at the nose of the aircraft and flow backwards along the length of the aircraft. Managing this shockwave and assorted drag is critical for supersonic flight.

Hi,

I thank you very much for explaining it---.

It shows that same aircraft frame designed for different utility may have different flight characteristics under different circumstances---which may also make it an aircraft for a different kind of utility---.

An F35 is a good example of that---.

 

[messiach]

I am talking about FC1b forebody vortex generators. Perhaps it has generated some confusion.

Hi,

So---it is early 90's and I am selling Lincolns at Beverly hills---. This beautiful older white lady comes looking for a Lincoln Town Car---the size of diamond on her ring finger was almost the size of my thumbnail---.

I started answering her questions and added some technical inforemation as well---.

She retorts---'youngman---speak to me in english---. I got mad---and told her I am speaking in english---and I have a very good accent as well---. She got mad and left---.

I told my boss who was a white guy----he crakced up---say to me---she was not talking about your language skills---talk in english meant---speak in simpler terms that a lay person can understand---and I laughed and laughed and laughed---and still do at my ignorance---.

So---please explain this in a simpler language---sometimes this technical jargon flies over the top of my head---

 

[CriticalThought]

I am talking about FC1b forebody vortex generators. Perhaps it has generated some confusion.

But madam, I fail to recognize any VGs in the forebody by looking at the published pictures of the two prototypes. Am I missing something, or will they appear in later prototypes?

 

[MastanKhan]

I am talking about FC1b forebody vortex generators. Perhaps it has generated some confusion.

Hi,

No it has not---and you have not created any confusion---.

Eid Mubarak from california---.

 

[messiach]

Eid Ul Fitr mubarik.

Hi,

No it has not---and you have not created any confusion---.

Eid Mubarak from california---.

Vortex strakes are clearly visible alongside the canopy. Such configuration can be used to test some aspects of supercruise.

But madam, I fail to recognize any VGs in the forebody by looking at the published pictures of the two prototypes. Am I missing something, or will they appear in later prototypes?

 

[Thorough Pro]

Why on starboard only?

Vortex strakes are clearly visible alongside the canopy. Such configuration can be used to test some aspects of supercruise.

 

[Armchair]

I thought those were hinges... (?)

 

[CrusherChamp]

Wooooow

 

[CriticalThought]

Eid Ul Fitr mubarik.



Vortex strakes are clearly visible alongside the canopy. Such configuration can be used to test some aspects of supercruise.

Thank you. But why on one side of the aircraft only? And wouldnt this lead to an increased frontal RCS? Will they be activated as needed? Or they are permanently fixed in open position?

 

[MastanKhan]

I thought those were hinges... (?)

Hi,

Round and round and round we go

Where we end up---nobody knows.

 

[Gallium Nitride]

Look, I am your friend when I say this. Try to apply logic to what you have heard. The green color is all over the aircraft, even at the edge of the intakes. It cannot possibly be true that behind each and every green panel, there is fuel storage. Probably there are a few panels that do indicate fuel, and we can probably guess them. But most certainly the vertical tail on Thunder B does not have the required volume.

As for the vertical tail on F-35, there is one single picture on the internet that indicates fuel storage on the vertical tail. I cannot find any written confirmation from authentic sources. You cannot form an informed opinion based on one picture on the internet.

@gambit can you please shed light on the claim that the vertical tail on some version of F-35 stores fuel in it?

Lol! It's upto you to agree with me, I am luckily one of the few here who have knowledge about each and every bit of the JF-17, and I am also working on its simulator and have personally seen this JF-17B (also saw it today lol).
And observe the picture I've attached, the block II aircraft only has fuel in fuselage while in JF-17B we have fuel addition to the Vertical tail and Strake/intake areas. I still would have no problem if you don't agree

 

[CriticalThought]

Lol! It's upto you to agree with me, I am luckily one of the few here who have knowledge about each and every bit of the JF-17, and I am also working on its simulator and have personally seen this JF-17B (also saw it today lol).
And observe the picture I've attached, the block II aircraft only has fuel in fuselage while in JF-17B we have fuel addition to the Vertical tail and Strake/intake areas. I still would have no problem if you don't agree

So those little protrusions under the canopy are VG strakes then and not hinges? What engine is being used on the B version? Have the specs for max speed changed? And do you have any updates on Block 3?

EDIT: Oh and in the pic of B version above, the nose cone is also painted yellow? How come? The nose cone is really sensitive area and is left untreated usually.