What's new

Qaher F313 l News & Discussion

Here the question is whether you are a better aircraft designer or that team behind the Qaher.

Your and the critics of the others are valid, but the likelihood that you or penguin are better designers than the Iranian team is low.

Hence I tried one or two pages back to provide and explanation for what we see. You either do that, or believe that a bunch of amateurs was hired for this project and you got the better ideas.
 
Vevak
It is clear that mass production of a product,make the product more economical for producer and consumer,but do you have any reason that Iran can not mass produce Qaher?

I emphasised on comparison of Qaher and f5 not to other fighter such f15 or f22,but of course scaling up Qaher to f15 s size can make more trouble in fighting for any enemy fighter,with of course modifying it's wing for higher speed and higher cieling altitude as you mentioned with double engine x36,which is not far to acheave with Qaher platform.

Qaher would have some varient easily,just look at fuselage which can attach to many kind of wing ,or other modification potentials in qaher's platform,and ....

That is what make it's platform a logical choose.

Remember that:

Other fighter's project consumed many time and modification also.
 
Last edited:
Here the question is whether you are a better aircraft designer or that team behind the Qaher.

Your and the critics of the others are valid, but the likelihood that you or penguin are better designers than the Iranian team is low.

Hence I tried one or two pages back to provide and explanation for what we see. You either do that, or believe that a bunch of amateurs was hired for this project and you got the better ideas.

The MAIN problem with the F-313 is not with the Team of Designers it's with the people above them who set requirements for them! And give them a budget!

The problem is not with the designers for every designer on that team has likely designed a better fighter....

The problem is with the people who despite the victories of the IRIAF in the Iran-Iraq war still haven't come to understand the value of an Air Force equipped with Air Superiority fighters & advanced Fighter Jets vs Large number of low cost Aircrafts
Maybe because IRIAF maintained Air Superiority over it's territory during the entire war, It's hard for them to comprehend what war would of been like if they didn't have Air Superiority but for whatever reason words like Force Multiplier & Air Superiority seem foreign to the people that set requirements for the designers

Because at the end of the day a country who is limited by the number of fighters it will be able to produce due to man power, equipment, funding and various other reasons shouldn't be choosing a light low cost fighter jet from the start as a requirement!

For Air to Ground missions a single F-4 is far more valuable than 3-4 F-5's
For Air to Air operation a single F-14 is far more valuable than 10 Saegheh Fighters

And if you choose the Saegheh to produce because it's cheaper to produce and it's titanium requirement is 40x lower than an F-14 then you have to also understand and accept to produce 10 Saegheh Fighter for every F-14 and you also have to comprehend that doing so means in the future you would have to train 10 pilots for every 2 F-14 pilots, you have to fuel and provide weapons for 10 saegheh's vs every F-14, you have to maintain 20 engines for every 2 F-14 engines, you would eventually have to overhaul and provide all types of part for 10 saegheh for every F-14..... And you have to understand that this would be going on for decades!

So even if the Saegheh costs you $5 Million USD to produce as appose to an F-14 that would have cost you $100 Million USD to produce and even though 10 saegheh at the end of the day cost you less then a single F-14 it doesn't necessarily make them cheaper to fuel, equip & maintain in the long run!

And this is clearly something that Iranian officials, Generals & people who set the requirements fail to comprehend because if they did after the Saegheh they would not have bothered with another light low cost aircraft!
 
I agree on that.

Now the question is if the Qaher could be a design that has parity with F-15/16 and if two Qahers achieve parity with a F-22/35.
The question is also whether it was not very wise from Iranian decision makers to not go for a air superiority fighter race but first concentrate on BM's, then go for ground based air defense, then go for drones and now maybe for manned fighters.
I think it was very wise.

What is up for discussion is whether via a asymmetric approach the Qaher could reach those parity requirements or if the Qaher design is hopelessly lost in such a scenario.

Two pages back I tried to set up a scenario that could bring the Qaher in such a position via a very unconventional operation regime, here it is again:

We can set two boundary conditions and check if the methodical design result would be the Qaher.

1. Your engine technology is 3-4 decades behind that of your opponents.

2. Your country to defend has one of the most mountainous topographies on this planet, where mountain chains are 2000m on average.

The resulting design can be independent and no foreign companies or mainstream idol designs have influence on it.

In such a case a result could be the following:

Make use of the mountainous terrain to avoid detection by radar, IR and ESM. The design has to fly low in valleys to mask it. I wont go for the high altitude high speed game of air superiority fighters, hence no long range radar-tech/engine-tech driven BVR engagements. Now difference of speed at sea level is at best around 30% for a subsonic fighter and a advanced opponent fighter with advanced engine-tech due to the high drag. This lower speed difference compared to low engine-tech vs. high engine-tech engagements at high altitude helps to compensate.

As for the deficits with the engine, a physical effect, the ground effect is taken into the design, which effectively creates more thrust. A possible turbofan variant of the J85 at 70s tech level without afterburner, optimized for low altitude, plus the bonus by the ground effect, decreases the gap in engine-tech. It may provides mach 0,9 for a draggy internal weapon VLO design.
In a hunt, the opponents high engine-tech fighter, far from home base on short afterburner might do mach 1,3 with or without internal weapons, a short-lived difference of 30% for 30 years difference in engine technology.
Its clear that this 1:1 hunt scenario is not everything and the opponents fighter will try to shot it down from higher altitude, look-down. However the topographie will always force it to get close in order to have a direct line of sight for radar/IR and weapons and the VLO design will futher hinder long rnage shots from look-down positions. With a intact IADS and LR-SAMs the initial engagements could be limited to that low-altitude hunt scenario where the kinematic advantage of the modern fighter is decreased.

The Qaher is surely designed to make use of ground effect, its WIG like wingtips clearly point to it. Here is a technology where no experienced metallurgy is necessary, benefit by a physical effect affecting kinematics by developing a terrain avoidance system with digital maps and multiple redundant sensors. A mature terrain avoidance system for very low altitudes, state of the art. Ground effect was used on sea surface because land operation would be too dangerous but with today's technology this limitation can be eliminated.
Additional advancing communication technology with data-links and sensor-fusion/IADS could provide the Qaher with the necessary situational awareness to do its low level operation, approach a target, pop-up, attack and dive back and leave the battle. This dive/low-level subsonic escape is also a method used by the B-2 to out run interceptors that have detected it.

The tandem wing design is also noteworthy for the ground effect optimization. A question is what range performance would be possible for such a ground effect operating aircraft with an non-afterburning J-85 turbofan variant. Would the ground effect operation at mach 0,9 max. provide it with the same range performance as a medium to high altitude operating fighter?
The tandem wings have a interesting design, the forward wing/canard is conventional for a fighter, but the rear wing has a very thick leading edge. The benefit for such a thick wing profile is foremost the fuel that can be carried inside it, especially for a design that has internal weaponbays in the fuselage occupying space. The forward-wing apparently "breaks" the high speed airflow, so that the thick rear wing is just confronted with a low pressure region at the leading edge which could result into a thick wing as a airflow design result.
The decision not to go with a supersonic VLO design and stick to a low-level mach 0,9 design would also be a brave one, supersonic sounds good but in a operation regime hypothesized for the Qaher the effort-benefit ratio would be too low. In high subsonic operation the design gets much cleaner and more efficient.

Then there are always questions about the cost effectiveness. How much cheaper would be two turbofan modifications of the J-85 compared to modern engines (1/10 of a F404?)? How much cheaper is a small aperture low power AESA for 80km max. range against a 1m² target? How much easier design and hence cheaper is a VLO inlet like that of the Qaher? Just due to positioning it could provide the same VLO effect in its operation regime as complex fan-face avoiding supersonic designs. What high angle of attack penalties are expected for the inlet and how important are high AoA for its operation regime?
If all these trade-offs and design elements are clarified we can judge if the methodical design result of the Qaher makes sense or not.

Iranian defense industry are known for such unconventional designs and operation regimes, so this hypothesis might not be that far from reality.

At this point the project remains up for debate, neither IRGC nor IRIAF have shown support for it and development seems to be slow. Lets see if we see a airworthy prototype soon.

I don't say that whats described there is the Qaher but it is a positive scenario, beside all the negative ones we have seen.

For a fake fighter I sure would chose a FC-31 like design, what South Koreans, Japanese, Indians and Turks want to do, with intake and everything else at the right place.
 
This all is about a hypothesis for the operating regime of the Qaher, all theoretical. As you said this is a taxi or landing gear testing mock-up/demonstrator.

As for your answers:

It's known that downward cranked wingtips benefit from ground effect, most GEV have them. Here it is demonstrated ultimately by nature:

5251682236_c7717bc923_b.jpg


I expected this to be known widely. The Qaher needs a wing position like that with those wingtips to use a sane looking landing gear design and many GEV have that for similar reasons.

Secondly. Tornado is not using GE and does not need to fly at 15-20m and it does not, nor would it be technically feasible at that time to develop such a terrain avoidance autopilot. Today it might be, but this is theory.
simply google ' ground effect vehicle' and select images to see this is clearly not true
noone claimed it did!
I would have to disagree there: it could and did. It is how it operated in Gulf war. Someone here claimed that because Iran can make seaskimming missiles, it can do this for a jet. Well, go figure what missiles were available in the day when Tornado first appeared: Sea Eagle, Exocet, Kormoran etc. The argument works both ways. Tornado is late 1970 introduction into service. F-111 of early 1970s already did 100ft flight automated. The technology was originally developed by Ferranti for use with the TSR-2 aircraft...This technology is primarily used by military strike aircraft, to enable flight at very low altitudes (sometimes below 100 feet (30 metres)) and high speeds, avoiding detection by enemy radars and interception by anti-aircraft systems.


16m:50s. Able to fly supersonic at a height of between 100 and 200 ft (30-60m).
24m40s: early f111 had very basic navigation kit. upgrades gave the F111 very similar capabilityies to Tornado
29m38s: on a bombing mission ... the computer flies the aircraft fully automatically
30m05s: at 200 ft without the pilot touching the controls
31m: the nav attack system has been designed to keep you at 200ft above high ground or obstacle with no visual references
 
It is NOT logical at all especially when your not capable of mass producing Airframes & Engines in large numbers!

F-15's & F-22's can take out 6-8 F-5's or Saegheh with ease go back home reload and come again! Most likely they'll just fire at you with 6 BVR missiles & go back home to re-arm

If Iran is going to build a fighter that makes sense economically then they need to mass produce them at extremely high rates & they need to be cheap enough so that you can build, fuel, supply and maintain 10 fighters of your own at a minimum for every single enemy Aircraft! Even at a rate of 10 to 1 in an Air to Air battle I would still take a single modernized F-15 over 10 Saegheh Fighters because even if the F-15 is stuck without any weapons because of it's speed and range no F-5 or Saegheh fighter will ever be able to catch it!

Just because a fighter is cheaper or is easier to mass produce it doesn't necessarily make it more economical in the long run! You still have to train 10 pilots for every one of theirs, you still have to provide weapons for 10 Aircrafts for every one of theirs & you still have to maintain, fuel & overhaul 10 Aircrafts for every single one of theirs

As for the redesign they have to fix the Wings & canards (elevators) and if it was me I would also redesign the inlets which would require them to redesign the entire fuselage

Iran would be better off just building a twin engine version of the X-36 either with advanced fly by wire & thrust vectoring control OR with added V shaped stabilizers with a less advanced fly by wire system

They don't usually fight alone anyways.


During Gulf War.
120319-D-LN615-001.JPG
 
@Penguin

simply google ' ground effect vehicle' and select images to see this is clearly not true

Did that and it gave me nothing about aerodynamic wingtip-design behavior of ground effect vehicles.
But my aerodynamic feeling tells me that inward chanted wingtips would help to concentrate air cushion high pressure region below the aircraft.

As for the rest. Well it sounds like flying at 15-20m over ground in 2017 could be feasible.
 
@Penguin



Did that and it gave me nothing about aerodynamic wingtip-design behavior of ground effect vehicles.
But my aerodynamic feeling tells me that inward chanted wingtips would help to concentrate air cushion high pressure region below the aircraft.

As for the rest. Well it sounds like flying at 15-20m over ground in 2017 could be feasible.

OK I have the utmost respect for you but "aerodynamic feeling" made me laugh more than it should have! :omghaha:
 
.Secondly. Tornado is not using GE and does not need to fly at 15-20m and it does not, nor would it be technically feasible at that time to develop such a terrain avoidance autopilot. Today it might be, but this is theory.
Are you joking ? :lol:

I was on the F-111 for five yrs. In the WSO seat, I can tune the terrain following radar to pick up surface waves while flying as low as 10 meters over the English Channel. At that level of sensitivity, the TF radar commands the auto pilot to treat each wave as if it is a hill.

Further, your terminology is incorrect. Terrain Following (TF) is up/down or flying over. Terrain Avoidance (TA) is considerably more complex. Terrain Avoidance (TA) have an altitude limit where the aircraft is not allowed to breach. If the radar calculate the obstacle's clearance altitude to be higher the limit, the aircraft will navigate around the obstacle. Terrain Following (TF) and Terrain Avoidance (TA) are very different technical beasts with different modes of operations.

http://www.northropgrumman.com/Capabilities/ANAPQ164Radar/Pages/default.aspx
The APQ-164 provides the B-1B with a Monopulse Ground Map (MGM) for an all weather area navigation aid. It provides a precise all-weather automatic Terrain Following (TF) and Terrain Avoidance (TA) capability for the B-1B.
 
Thanks gambit.

I always take a conservative position in such cases.

So if I understand you correctly the terrain following or/and terrain avoidance radar would be capable to provide a robust altitude of 15-20m? Even over ground in middle of a rocky vally?
 
Thanks gambit.

I always take a conservative position in such cases.

So if I understand you correctly the terrain following or/and terrain avoidance radar would be capable to provide a robust altitude of 15-20m? Even over ground in middle of a rocky vally?
If you are asking if the aircraft so equipped is capable of maintaining that low altitude, then -- yes.

Low altitude flying is very stressful, contrary to what most non-flying people may think. Generally, we think of flying as 3 dimensional with altitude. However, the lower that altitude factor, the more the flight approaches being 2D. When I learned to fly in high school in a Cessna 152, even 1000 ft, or about 300 meters, was considered dangerous. If you lose thrust or ability to lift, gravity will eat up that 300 meters real fast.

On the F-111, there was no terrain avoidance (TA) capability. If we want to fly as low as possible to avoid radar detection, then TF flight was out of mission planning, and F-111 and Tornado aircrews are the best at it. But for your question, if mission planning have the F-111 going thru terrain, then there is no need to fly that low.. Terrain masking will work for the jet.
 
This is also what I know, piloting at very low level flight is not sustainable.

For the proposed Qaher operation regime a continuous flight altitude of 15m is proposed to make use of ground effect, not for radar masking purposes.

A terrain following and avoidance system, fully automated with interpolated flight trajectory, a robust one able to confidently avoid e.g cables. The question is if such a autopliot would be feasible, at least with 2017 technology.
 
This is also what I know, piloting at very low level flight is not sustainable.

For the proposed Qaher operation regime a continuous flight altitude of 15m is proposed to make use of ground effect, not for radar masking purposes.

A terrain following and avoidance system, fully automated with interpolated flight trajectory, a robust one able to confidently avoid e.g cables. The question is if such a autopliot would be feasible, at least with 2017 technology.
Shouldn't be harder than autonomous driving system while you can mount a lot of more expensive sensors on a fighter jet.
 
Shouldn't be harder than autonomous driving system while you can mount a lot of more expensive sensors on a fighter jet.
it is ,when you hug ground at speed like say 500kn or 600km every wind you encounter is like an obstacle in fact the main problem in such low altitude flight is not earth but air.
 

Pakistan Affairs Latest Posts

Back
Top Bottom