Qaher F313 l News & Discussion

[SOHEIL]

Quite embarrassing......

Why are you persians actually defending this piece of junk? No proof it can actually fly other than some I'll prepared CGI......

You guys are quite resilient and you've dealt with sanctions quite well but you can't make a 4th jen fighter never mind a 5th gen.

Regards

It's not far ... Let's see !

ALCON,

Concerning that size of the F-313, something to keep in mind:

If it really is 16 meters long, that would make it just a meter or so shorter than a MiG-29 and any comparison between these two birds will tell you right away that it is MUCH smaller. I'm personally confident it's shorter than a F-16 as well (~15 meters in length) because I've given one a walk around on several occasions.

Now, 16 meters of length may be how big it ends up being someday but IMHO there is no way that aircraft we've seen is anywhere near that size.

It's not as though this was the first time an Iranian news org was flat-out wrong on something (see the "50mm" sniper rifle thread for a recent example).

13m

 

[Super Commando Dhruva]

We are going to see this in blue sky soon enough !

Maybe you don't know anything about Iranian people ...

Just for comparison ...

buddy its not about how it looks from out side, its about whats inside the plane. You guys are very good in making carpets and petrol that we buy when whole world refused your oil. i am sorry it just a I wash.

 

[VEVAK]

well I don't see any different
let ask you a question if you plan for a mission to strike a target which one is preferable
1 - sneak under radar let say between 30-50m with a stealth airplane at for example 700km for 1000km
2 - fly with F-16, F-18, Mig-25, SU-24, Mig-29 at 13km of altitude with a speed of 850km for 1000km

the point is all of them are subsonic unless they want to use afterburner and have fuels for only 20min of flight.


and what they stated as the mission for this airplane won't made it necessary to be supersonic


and what that is? as far as I'm aware optimal cruise speed and altitude is a lot different between different airplanes.
for D=F-5 its something for SR-71 its something else and for U2 another thing .


let me assure you no airplane is maneuverable enough to out maneuver modern Air to Air missiles as matter of fact no human can stay conscious after pulling the turn needed to out maneuver a modern missile.

I assure you that there is no real need for actual flight to conclude that and the designers knew of it before hand and that's why they never advertised it as a fighter while they did such with Saeqe

In terms of speed, yes when compared to an armed F-16 with a fuel tank and Air to Ground weapons it wont be much different and it will have a lower RCS and greater control at lower altitudes something the F-117 lacked at lower altitudes but it's RCS was also lower but at the end of the day the optimal cruise altitude will NOT BE 30-50 meters
Your optimal cruise altitude will always be closer to your maximum altitude than to the ground that is a FACT no wing design or engine will ever change!

Also, since your a low RCS fighter the greatest risk to your aircraft will be optical sensors & weapons guided by them and if your designing a fighter to fly at low altitudes, at low speeds with low maneuverability then you need to build it like a tank much like the A-10 & the Su-25 so AAA equipped with optical sensors don't rip you to shreds but the Q-313 is clearly not built like that

Also your wrong about outmaneuvering incoming missiles! A good pilot with a high maneuvering aircraft and advanced sensors can outmaneuver them! If SAM were that advanced you wouldn't fire them in tandem at each target! And even if the most advanced SAM were as you say that advanced not every country has them and even if they do have a few they don't have them at every location but they do have AAA systems

A 5th Gen fighter is a fighter that should be able to take out it's target from high altitudes out of reach of AAA systems and short ranged SAM's (~30km)

Don't get me wrong the F-313 is a great step forward for Iran's fighter program especially if it truly does possess an internal weapons bay that is a great achievement BUT many facts are still unknown about this aircraft!

Will it pass the test required to get to a production model?
How much will each cost?
What is it's payload capacity?
Will it have any type of Air-Air Missiles?
What is it's range?
Will the production model have Air refueling capability?
What type of sensors will the production model have?

At the end of the day Iran CAN NOT stop here! Iran needs to produce it's own Air Superiority fighter with an internal weapons bay and if successful this is a great step forward towards that direction!​

 

[Yousef]

I've got to a conclusion, regarding the plane. I'm a software engineer, so I might be wrong. I think limitations lead to this design. Iran (if?) could have reverse engineered and manufactured J85, needs to rely solely on that, and since it is under sanctions, they should get the best out of it, which leads to deterrence, and not dogfight. I believe, they wanted to have a plane that could have a good ability to outmaneuver some planes and antiaircraft missiles, as much as it could. It doesn't need to have lots of payloads, and it is designed to attack targets like ships, strategic targets or UAVs. So based on my hypotheses, I will try to explain the design.

The stealthy look: Try to evade radars, as much as possible, not necessarily completely.
Drooped wing tips: They could increase instability, which is a good thing, when the plane turns right/left, and it increases effective wings' length.
The front wings: It looks neutral for straight flight, for the most part, and it is for maneuverability up/down.
However, why other manufacturers didn't use such design? Because they have various engines at their hands, and advanced processing units that is handling aerodynamic of plane. I think the designers were trying to use the most of what they had. Anyway, I think it's a necessary step, so it's a step forward.

 

[The SC]

Maybe for its intented missions, we should compare the Q-313 to the British and American subsonic aircraft Harrier:

The Harrier, informally referred to as the Harrier Jump Jet, is a family of jet-powered attack aircraft capable of vertical/short takeoff and landing operations (V/STOL). Originally developed by UK manufacturer Hawker Siddeley in the 1960s, the Harrier emerged as the only truly successful V/STOL design of the many attempted during that era, despite being a subsonic aircraft, unlike most of its competitors. It was conceived to operate from improvised bases, such as car parks or forest clearings, without requiring large and vulnerable air bases. Later, the design was adapted for use from aircraft carriers.

There are two generations and four main variants of the Harrier family, developed by both UK and US manufacturers
https://en.wikipedia.org/wiki/Harrier_Jump_Jet

The McDonnell Douglas (now Boeing) AV-8B Harrier II is a single-engine ground-attack aircraft that constitutes the second generation of the Harrier Jump Jet family. Capable of vertical or short takeoff and landing (V/STOL), the aircraft was designed in the late 1970s as an Anglo-American development of the British Hawker Siddeley Harrier, the first operational V/STOL aircraft. Named after a bird of prey,[8] it is primarily employed on light attack or multi-role missions, ranging from close air support of ground troops to armed reconnaissance.

https://en.wikipedia.org/wiki/McDon...II#Specifications_.28AV-8B_Harrier_II_Plus.29

 

[Arminkh]

Very fat WW2 style wings, no inlet diverters, no afterburner, no edge flaps... everything shows that thats subsonic plane..


Funny thing is that I've wrote about Bird of Prey 4 years ago as well:

https://defence.pk/pdf/threads/ghaher-313-fighter.232805/page-30#post-3877683

BTW the idea of Bird of Prey was that its totally canard and tailless but Qaher has both canards and tails.

That's not my answer. Just so you know, sound travels at 1234 km/hr. So an airplane that can only fly 1200 km/hr is subsonic.

You said it can achieve max 500 km/hr. Where did you get that number from?

 

[TopCat]

Does Iran have Fly-by-Wire technology in hand. What about the other aircraft Iran made before? Do they have fly by wire?

 

[Arminkh]

Here some simple calculations to put this speed debate to bed:

This is the drag formula thaat determines the max speed of an object moving inside a fluid:

behind the object. The equation is

FD=1/2ρ u^2 CD A

FD is the drag force, which is by definition the force component in the direction of the flow velocity,
ρ is the mass density of the fluid
u is the flow velocity relative to the object,
A is the reference area, and
CD is the drag coefficient

To see how fast Q-313 can theoretically go let's put numbers in above equation:

FD will equal it's engine thrust. 2xJ-85 without after burners will provide 26 KN thrust.

Density of air is 1.255 kg/m3

A let's say 15 m2 even though that's overestimated.

CD or drag coefficient is usually around 0.02 for fighter jets but let's use that of Boeing 747 for the sake of conversation : 0.031

Solving for u, th max speed will be 298 m/3 or 1074 km/hr.

More than enough for air support or ground strike aircraft.

Now if the drag coefficient is reduced to that of f-4, which is 0.21, the speed will be supersonic.

 

[Arminkh]

And they are must have for supersonic jets, unless u have DSI or cones. Qaher has neither. Even for transonic jets they are recommended.

They are called splitter plates and their role is to separate the boundary layer that is moving with the same speed of that of the fuselage from the fast moving air.

What determines whether boundary layer would cause a problem is where the inlet is located. If the inlet is close enough to the tip of the nose, where the boundary layer is not formed, then splitter plate is not required.

In case of Qaher, the inlet is much closer to the tip of the nose than F-5 or Rafael.

 

[The SC]

Another video

 

[500]

That's not my answer. Just so you know, sound travels at 1234 km/hr. So an airplane that can only fly 1200 km/hr is subsonic.

You said it can achieve max 500 km/hr. Where did you get that number from?

Wing profile, small flaps, lack of edge flaps (or how u call them), intakes shape, shows that its not even transonic but subsonic. OK if u put good fly by wire and powerful engines u can make max speed higher, but its not optimized there.

 

[eagle2007]

ALCON,

Just something to keep in mind with the subsonic/supersonic conversation:

The speed of sound is NOT constant. It varies depending on altitude. The speed of sound at sea level vs 10,000 meters differs by a factor of ~150kph.

So the typically quoted 761mph/1225kph figures ONLY apply at or very near sea level.

This effect is because the temperature and density of air seriously effects the speed sound travels through it.

As such, unless it is specifically stated, most "top speed" figures you see for jets (both military and civilian) is their maximum speed achievable at altitude of 30-35,000 feet.

Just some food for thought.

 

[WordsMatter]

I am not an expert in aerodynamics or "any" generation fighter jets. My problem isn't that IRI is trying, but the fact that IRI mouth piece, IRIBC, is outright lying about what this plane is. If you saw the video, the "expert" (I am sure a paid retard expert) claims everything about this plane is domestic. That's just a lie, thus leading me to conclude this is just another propaganda stunt by a "alternate reality" regime. This is meant to fool Iranians that their elite are responsible and steadfast, a far cry from reality. Sad really.

 

[JamD]

Here some simple calculations to put this speed debate to bed:

This is the drag formula thaat determines the max speed of an object moving inside a fluid:

behind the object. The equation is

FD=1/2ρ u^2 CD A

FD is the drag force, which is by definition the force component in the direction of the flow velocity,
ρ is the mass density of the fluid
u is the flow velocity relative to the object,
A is the reference area, and
CD is the drag coefficient

To see how fast Q-313 can theoretically go let's put numbers in above equation:

FD will equal it's engine thrust. 2xJ-85 without after burners will provide 26 KN thrust.

Density of air is 1.255 kg/m3

A let's say 15 m2 even though that's overestimated.

CD or drag coefficient is usually around 0.02 for fighter jets but let's use that of Boeing 747 for the sake of conversation : 0.031

Solving for u, th max speed will be 298 m/3 or 1074 km/hr.

More than enough for air support or ground strike aircraft.

Now if the drag coefficient is reduced to that of f-4, which is 0.21, the speed will be supersonic.

I have little interest in the debate going on, on this thread, but I felt compelled to correct your post as it is VERY MISLEADING and INCORRECT. I don't want casual readers to get misinformed.

• The formula you have listed is a semi-empirical approximation of the drag force.
• The coefficient of drag VARIES with Mach Number. Perhaps you have never seen curves like these:
  
  
  What did you think the "sound barrier" was?
• For an aircraft not designed with Whitcomb's rules for transonic and supersonic flight the bump in the above graph of CD is SO VERY LARGE that the aircraft never goes supersonic. Famous example is of YF-102 redesign with area rule to allow it to go supersonic:
  
  
  
  Just look at how even the one on the right is sleek and has thin wings and yet it was limited to Mach 0.98 due to something you can barely see (pinching of fuselage near wing root).
• Among other things airfoils have to be chosen to lower the "bump" of the Cd curve. Thick airfoils (like the one on F313) will have the bump at MUCH SMALLER Mach numbers (probably around 0.6) as the flow goes locally supersonic.

Please do not mislead people with equations and formulas when you have little or no appreciation for the subtleties involved. It's not the end of the world if the F313 isn't designed to go supersonic. Irani aerospace engineers are NOT idiots, that they will not know all that I've said above, and try to push the F313 through the sound barrier. When you insist that it will go supersonic you make your own country's engineers look stupid. They know they were doing, you don't.

I have been around military aviation for a good chunk of my life, including childhood starting with Hickam AFB, Hawaii. Then onto the AF with the F-111 and the F-16. I know what it is like cresting the hilltop in hard terrain following (TF) flight in the 'Vark and how crushing is 9g in the Viper.

There is something very off with this Iranian aircraft and I use the word aircraft very generously here. It size seems to be undersized compares to the human pilot and I have been around some small fighters like the A-4. The Qaher's size seems to be like that of a trainer rather than of a line combatant. For that wing span, it would require a higher than normal TO/L speed, which I do not see how possible with the small engines. The wings looks awfully thick. And where are the leading edge (LE) flaps ?

There are too many things odd about this 'aircraft' where even if it can fly, I cannot see how it can be a fighter.

I am quite certain their engineers have designed a jet-powered ground effect vehicle to possible attack US Ships with but their media, government, and fanboys have started assigning characteristics to it for which it was never designed.

 

[VEVAK]

Does Iran have Fly-by-Wire technology in hand. What about the other aircraft Iran made before? Do they have fly by wire?

Fly by wire tech is nothing special! Especially with computers and processing power available today! It's just a matter digitizing every thing recording it via trial and error....
Iran's Saegheh has Fly-By-Wire tech
Fly by wire tech was something hard to achieve in the 70's & early 80's not today today their are different generation of fly by wire tech for example the most advanced versions can detect if a pilot has passed out due to high G forces and automatically take control of the aircraft and they can automatically fly the aircraft to it's destination if needed....

So achieving fly by wire is nothing special it's how advanced your fly by wire is that matters