JF-17 Thunder Multirole Fighter [Thread 5]

[Zarvan]

View attachment 36185

Is this BLOCK II

 

[razgriz19]

guys just a simple question.do these jets have keys like cars.how its ignition take place.thanks in advance

its all switches, although in small airplanes like Cessna 150, 172, i have seen keys for the starter
I have started a jet engine before (PT-06)
steps are almost the same for every other airplanes, newer ones are easier.

battery on, master on, fuel pumps on, etc
start the APU (Auxiliary Power Unit / mini jet engine) because its a mini jet engine, it can be started by using an electric starter.
Once the APU is online, it provides all the electrical power, and pneumatic discharge pressure (high pressure air) needed to start the main engine. The pilot then just engages the starter (in older airplanes you have to watch for certain things such as temperature, oil pressure for lubrication, etc. In newer aircraft, everything is controlled and monitored by the FADEC, a computer that does everything for the pilot basically)

 

[ejaz007]

@Chak Bamu

I wasn't aware the news has already been shared

 

[VCheng]

I always wondered Why Jf17 varies less internal fuel despite being slightly longer then Gripen? and why JF17 has shorter range despite having a smaller (less consumption) engine? are we sure the released stats about internal fuel quantity and range are not conservative?

The construction techniques used for the JF-17 are a generation or two older than the ones used for the Gripen, resulting in a heavier unloaded airframe that can carry only so much, given its engine.

 

[Chak Bamu]

The construction techniques used for the JF-17 are a generation or two older than the ones used for the Gripen, resulting in a heavier unloaded airframe that can carry only so much, given its engine.

Generation or two? Are you saying that JF-17 is 2nd generation in its construction? It sure does have a couple of wings, a fuselage, an empennage, and tires etc... but what other similarities can you find with 2nd generation planes?

We could do with fewer rivets, yes. We could improve the composite content. We could improve the Wing / Fuselage join. But that is not the real reason.

The real reason is the philosophy of the plane to control its cost to make it cheap to own, operate, and maintain. The engine probably has a greater role than the construction. But the compromise works very well for PAF. It does not matter if someone finds an invalid reason to equate JF-17 to 2nd generation war-birds.

 

[VCheng]

Generation or two? Are you saying that JF-17 is 2nd generation in its construction? It sure does have a couple of wings, a fuselage, an empennage, and tires etc... but what other similarities can you find with 2nd generation planes?

We could do with fewer rivets, yes. We could improve the composite content. We could improve the Wing / Fuselage join. But that is not the real reason.

The real reason is the philosophy of the plane to control its cost to make it cheap to own, operate, and maintain. The engine probably has a greater role than the construction. But the compromise works very well for PAF. It does not matter if someone finds an invalid reason to equate JF-17 to 2nd generation war-birds.

The JF-17 relies on conventional construction techniques in use for many decades, and like you said, still works very well for PAF. You can compare unladen weights and payload capacity to get an objective idea of what I am saying.

 

[Chak Bamu]

The JF-17 relies on conventional construction techniques in use for many decades, and like you said, still works very well for PAF. You can compare unladen weights and payload capacity to get an objective idea of what I am saying.

I know all that. I am just amazed at the ease with which you can insert subliminal content and subsequently not be bothered to back it up. The non-stick teflon approach is really slick.

 

[VCheng]

I know all that. I am just amazed at the ease with which you can insert subliminal content and subsequently not be bothered to back it up. The non-stick teflon approach is really slick.

There is nothing subliminal in what I have said. The numbers do not lie:

The empty weight of a JF-17 is about 14,500 lbs, and it can carry a payload of about 6500 lbs.

The empty weight of a JAS-39 is similar at about 14,500, but it can carry a payload of about 11,500 lbs.

Building an airframe that is light and yet strong requires not only good design, but contemporary construction techniques. The JF-17 is a blast from the past. But it does work very well for PAF, as I have said all along.

 

[Tempest II]

Concerning the payload of the Fc-1, I thought last year they tested upto double the load the the structure passed? this was static load I believe so dynamic load will be a lot less than the 200% in the test.

From my knowledge the old methods tended to over design to be on the safe side. It could be the same here - where the design is good enough but tests have not been done to set higher limits. So the product is released with clearance for reduced duty (flight envelope) which is then expanded as they do more tests and gain confidence.

We already been told Block II we have increased capacity. I don't remember a change in structure, I could be wrong.

Just my thinking.

 

[VCheng]

Concerning the payload of the Fc-1, I thought last year they tested upto double the load the the structure passed? this was static load I believe so dynamic load will be a lot less than the 200% in the test.
From my knowledge the old methods tended to over design to be on the safe side. It could be the same here - where the design is good enough but tests have not been done to set higher limits. So the product is released with clearance for reduced duty (flight envelope) which is then expanded as they do more tests and gain confidence.
We already been told Block II we have increased capacity. I don't remember a change in structure, I could be wrong.
Just my thinking.

A nearly 75% "over-design"? Limitation to only 60% of payload ability "just to be on the safe side"? I think not. Even the old methods are not that far off.

 

[Tempest II]

A nearly 75% "over-design"? Limitation to only 60% of payload ability "just to be on the safe side"? I think not. Even the old methods are not that far off.

Icon of the Air

Arguably, the B-52’s biggest asset lies in its “overdesign.” That “goes way to the top of the list of things done right” by the original engineers, says Oathout, who notes there was no computer modeling when they designed the world’s first high-altitude bomber. “There were a lot of unknowns they just overdesigned for, and they just nailed it.” It also helps that the jets have logged only 18,248 hours in the air, on average. Though originally expected to fly 5,000 hours over its lifetime

 

[VCheng]

Icon of the Air

The B-52 first flew in 1952, and was designed well before that. How is that even remotely relevant to the JF-17? Or do you wish to say that its design philosophy dates back to that era?

PS: The B-52 has had many structural upgrades based on newer technologies to keep it flying beyond the original designed limits.

 

[Tempest II]

The B-52 first flew in 1952, and was designed well before that. How is that even remotely relevant to the JF-17? Or do you wish to say that its design philosophy dates back to that era?

PS: The B-52 has had many structural upgrades based on newer technologies to keep it flying beyond the original designed limits.

I am saying overdesiging has been/is the "safety factor" when there is no experience with a product. Simulation has only gained wider use recently.

I am not stating the issues around the FC-1 as facts. I am considering possibilities ... ... especially in light of a release that the structure passsed 200% load of the design weight. They are simulating the load ... ... i.e. engineering optimisation and fing that it can do more than they thought. The word "overdesign" comes to mind.

 

[OCguy]

I think what you are trying to get at is the thrust capability, which the JF-17 compensates for by loading less fuel.

All reports from Pakistan say that mechanically the engines are top-notch, and I am sure the next generation will improve immensely.

Thrust-to-weight ratio - Wikipedia, the free encyclopedia

 

[VCheng]

I am saying overdesiging has been/is the "safety factor" when there is no experience with a product. Simulation has only gained wider use recently.

I am not stating the issues around the FC-1 as facts. I am considering possibilities ... ... especially in light of a release that the structure passsed 200% load of the design weight. They are simulating the load ... ... i.e. engineering optimisation and fing that it can do more than they thought. The word "overdesign" comes to mind.

Okay, I can accept that possibility then, though I would consider it remote, that the JF-17 is over-designed to that extent. The basic design comes from Mikoyan, and is based on well-known construction techniques from the 70s.