Kowsar Ver II - Possibilities !

[Mithridates]

well poor F-5 was always test bed for various projects in Iran. these possibilities comes to my mind:
engine: could be the same J-85/owj, Iranian version of GE J-79, RD-93 or turbofan version of owj.
the thrust/weight ratios considering engine weight and out put thrust would be like this (F-5 with 2 tons of fuel and 700 kg payload):
for GE J-79==> T/W=0.93 N/kg
for RD-93==> T/W=1.04 N/kg
for J-90 (1.33*owj/J-85)==> T/W=0.82 N/kg
for ordinary J-85==> T/W=0.62 N/kg
well considering that we might see an F-5 with GE J-79, i couldn't stop thinking what would happen if we mount a similar engine like Lyulka AL-21 on F-5:
for AL-21==> T/W=1.3 N/kg
this is a double middle finger to F-35, F-22 and EF-2000 lol. however I'm not sure if it's feasible or not.
radar: if we use more powerful engine there is a chance that we completely change the structure to the original/planned saeqeh configuration that soheil shared it's images, the radome could fit with bayyenat radar. i once asked about bayyenat of someone he said it's really potent radar but he answered to any specifications with the word "pashm rezon" and dodged to give any information.
but if we have no plan to change the fuselage, then the best option is adding new IRST/FLIR. this could contribute to the qaher project too. otherwise there is no point in further investing as the grifo radar onboard of kowsar-1 is quite enough for the role it intended to. note the fact that Raad-2 EO sensor has 80 km range for an approaching fighter size plane and possibly more against targets with their exhaust exposed to it. also passive sensors consume less power and reduce the chance of being detected. the only problem would be designing airborne version of it that can handle +7g force, pressure decline and have higher field of view. so i guess a LOAL IR/EO missile makes more sense for it than RF guided ones.
and about the A2G munitions i think kowsar-1 can support any bomb and missile we maded.

 

[arashkamangir]

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Reminds of that F/B-44 name that was being thrown around in the old IMF.

 

[TNT]

Imo, kowsar has lots of potential as a light fighter, but to achieve this, there are just some stuff that have to be changed and added to make it a true multirole light fighter that can act as the F-18 but with smaller payload.

The things that should be added or changed are:
- New turbofan engines with more thrusts.
- New ARH air to air missile.
- Increase in the wingspan and the wings should be connected to the upper part of the fuselage.
- The addition of a cheek pylon similar to the F-18 and the development of a special targeting pod to be placed on that pylon.
- Addition smart air to ground bombs which should be very easy to do.
- Addition of HOTAS controls for easier management of assets available.
- A data link system that connects the kowsar to the AD systems all around iran, drones and other planes equipped with the data link system.
- Aerial refueling ability.

Other optional things that can be added are:
- A helmet mounted display with both air to air and air to ground functionality.
- SEAD, antiship, light cruise missiles.
- Jammer pods.

The new engine would be a slight challenge but iran is already working turbofan engines, so it should be easy to develop an engine for the plane if they have the knowledge. The ARH missile shouldn't be that hard as iran already has experience in this field, they should just develop a good engine for the missile and a good design. The design changes need some research and work but are possible. The HOTAS should be worked on to make it easy to use and efficient. And the rest of the work is just coding to make the plane's systems compatible with the weapons that should be added.

Lolz so u mean basically everything. I guess just stealth is left behind.

 

[hussainb72]

Lolz so u mean basically everything. I guess just stealth is left behind.

If we are talking about a light multirole fighter then most of these changes are necessary to achieve this multirole status. But some of these changes wont cost that much which means that they can still be implemented.

 

[Shams313]

Reminds of that F/B-44 name that was being thrown around in the old IMF.

that design is more closer to f 20 the single engine variant of f5.
And also that design is around for years and there should be activity on that project. All the shortage i can see is that single engine ,with out rd 33 it's not reasonable to hope.
No news for sorfesh mahi...

 

[Mithridates]

that design is more closer to f 20 the single engine variant of f5.
And also that design is around for years and there should be activity on that project. All the shortage i can see is that single engine ,with out rd 33 it's not reasonable to hope.
No news for sorfesh mahi...

without RD-33 (or maybe J-79) we should not expect ground breaking innovation in structure. so the only remaining field would be the IRST, aerial refueling and maybe a canard configuration. i assume there will be a canard because the saeqeh was supposed to be like this:

so they needed to test double vertical stabilizer and they tested it over F-5 structure.
so if we have a canard qaher i assume we will test a canard plane to gain experience.

 

[PeeD]

The benefit of the F-5E was that it was a kind of U.S AK-47.
Normally U.S MIC is only profit oriented but back in those days they had a serious requirement to equip poor allies against the Soviets.
So it was a seldom case where a rugged and cost-efficient design was created by the U.S.
Northrop engineers goal was to turn the simple F-5A into a more simple and rugged design and bring down maintenance requirements and ease of it.

Knowing this the basic platform and the basic design solutions of the F-5E could be a enabler to a light fighter, that is cheaper, cheaper in price per flight hour and equal to better the Chinese JF-17.
The JF-17 also comes from a very effective design school of the Mig-21/F-7 but even improving on the F-5E, a light fighter could be created that has unequaled $/flight hour tag.

Kowsar was attributed to $16.5m with 10-20% imported parts and two instead of 1 engine.
The J-85 is a very simple design but a RD-33 copy would probably cost ~30% less than 2 J85.
Plus:
- A low power AESA could give the necessary performance of 75km vs. 1m² 4,5 gen. target and 100km vs. 3m² 4th gen. (all head-on, least RCS).
- An ARH BVR missile based on the SD-2C but in the rough size of the 9th-Dey SAM.
- Link-16 variant via RQ-170.
- IRST with 150-300km detection performance.
- Intakes that allow for near mach 2 max speed instead of 1,6.
- Iran has demonstrated a IFR probe in earlier projects, although it is a questionable capability for a light fighter.
- Self defense ECM pod and targeting pod have been demonstrated
- A by now reasonable large variation of air to ground weapons.

What is a must have for a Kowsar II 4,5 gen. light fighter is an IIR seeker missile and a HMS/D for targeting. This is something Iran would be lacking for now in order to complete the package.
To compete with the cheapest fighter on the export market, the JF-17, the key would be the biggest hurdle, a RD-33 copy reliable enough for a single engine aircraft.
If that is there and indigenous parts production reached ~95% that aircraft could reach a $17,5m production cost. With export profit the price tag could be $22,5-25m which would beat the JF-17.
Only a future block 3 JF-17 with AESA radar, IRST and more composite materials could reach same capability level and that's likely impossible to achieve below $30m with a Russian import engine.

The alternative would be to skip a Iranian F-20 and go with that IRIAF high wing design. I would only support that due to the larger nose and if ALL design emphasis is put on further simplifying the F-5E design. If optimization on costs and $/flight hour leads to changing the F-20 into that IRIAF model, then yes, go for it. However that means that your engineering is superior to that of those highly experienced Northrop engineers, possible in 2019.
The F-5 is already outmaneuver enough and kinematics would be ok too with a RD-33, so everything else is about the nose/radome to allow for a ~800 element AESA.

The resulting light fighter would then be maneuverable, have quite high kinematic performance via RD-33, reasonable radar and 2 WVR + 4 BVR AAMs. This is enough for something to scramble, dash to the target on supersonic speed, volley AAMs against opponents and return back home.
It is not something to enter enemy airspace, search for targets, attack, kill and re-engage other opponents.
The export market would be one thing that could be good for Iran, putting pressure on enemy pressure points along the IADS front is something that is good to have (if the enemy has not taken out the airbases by hypersonic weapons).

 

[PeeD]

To add to the last post: The F-5 is a design that can become a genuine 4,5 gen. fighter.
One of its inherent features when used in a single engine configuration is that the fan face of the engine is totally blocked. An AESA/PESA radar would allow a vertically angled operation that would greatly reduce RCS of the radome section.
With engine face and radar aperture reduced from the RCS budget total frontal RCS could fall below 1m². This would give it an important edge against many 4th gen. fighter radars. So RCS-wise it would become a reduced RCS 4.5 gen design.

The next area is situational awareness: With a glass cockpit and an AESA radar, scanning airspace would be improved significantly.

Then there is thrust to weight ratio: The F-5 is a very light design and the F-20 was below 6 tons empty. With modern materials and weight saving on the avionics side, 5,5 tons are possible and with the powerful RD-33 T/W ratio of over well over 1 is possible. This kinematic parameter can be seen as another qualifier for 4.5 gen fighters.
Intake design of the F-20/F-5 is also suited for mach 2 speed levels. In total a limited supercruise in some configurations could be possible, again a 4.5 gen. attribute.

It appears strange on the surface why someone would work on the F-5 design from the 50's a 3rd. gen fighter and may sound like a joke when it is claimed that a F-5 based design could enter the 4.5 gen. fighter category.
But this two posts have hopefully shown how that would be possible.
A 4.5 gen fighter for $25m on the export market is truly competitive product.
All attributes would put it into the 4.5 gen. category, even the tough one of kinematics.
Sometimes the key to success is not to look at others but go your own way.

 

[Ray_Atek]

Very good evidence to go to F-20 design.
Thank you for video
But don't forget need of big nose for bigger radar and mid wing design.

 

[Mithridates]

hey guys.
ever since this thread created by soheil an issue has stuck in my mind, is it possible to use a lyulka al-21 in an F-5 structure??
well to start this i should state that an F-5 with AL-21 can achieve a thrust/weight ratio equal to 1.3 .
without doubts it would make it a very agile plane, even better than F-22, SU-35 and EF-2000. after finding out this i was proud of myself and walking around happily and fantasizing a dogfight between F-15 and the mentioned plane or with EF or F-16( ) and then i told myself do not be silly, if it was possible US, Russia and Europeans would do that.
so i started to digging a little bit. i was suspected that maybe the drawback of such design (a heavy engine in a light weight fighter) is the fuel consumption. so i calculated internal fuel to fuel consumption of each fighter jet in an hour interval. the resulting ratio was around 0.3<R<1. the spectrum mentioned consisted of multi roles, interceptors, bombers and strikers. from what i understanded interceptors and strikers have near to 1 ratio, multi roles have <0.5 and bombers similar to multi roles and in some cases less than that. while interceptors and multi roles had thrust/ weight ratio near to 1. while in bombers and strikes case higher T/W is not necessary.
it kinda makes sense, bombers do not need heavy load of fuel as you plan to hit some point on the map before doing it, interceptors need hell lot of fuel to cover their country's air space and they need better T/W ratio to immediately increase their speed and reach the compromised point and obviously to maintain their agility against enemy fighters.
so i come to a conclusion that it does not matter which engine you have, you can make any type of military plane with that to fit your requirement, like soloviev D-30 that powers a fighter, a military cargo and an interceptor. or GE j-79 that powers A-5, F-4 and other military planes.

so lets get back to the F-5 with AL-21 theory and review what we got here:

F-5's internal fuel capacity is almost 2 tons (F-20 tigershark has similar number of 2.3) and each GE J-85 consumes 1.5 tons fuel per hour working at their MAX power. this makes a fuel capacity to consumption ratio of 0.66 . that number for F-20 is 0.6, EF-2000 is 0.5 and 0.57 for dassault rafale. but when you replace two J-85 with a single AL-21 that ratio drops to 0.3 which is a rare number in fighters except of MIG-21 which had the same exact number and that was not really remarkable plane with only 1000 km range.
regarding the physical changes that chaging two J-85 with one AL-21 would bring i mentioned improved T/W ratio, but another issue is that this kind of change will add another 1318 kg to plane and most importantly to the back of it and will cause instability in flight. how ever the empty weight does not change that much compared to tiger shark and the asymmetry of weight could be solved with changing the position of wings position:

so we see that this change in power plant results in better T/W ratio and worst internal/consumed fuel per hour.
so my question is:
1-no one does this (putting a heavy engine in a light fighter) because the plane would have a very conflicting result like ones in mig-21 that made it excellent regarding agility and disappointing regarding it's range.
2-isn't it possible to operate the AL-21 around 10 kilo newtons (cruising power for an F-5E)?? do the jet engines consume fuel with a linear relationship to the power or an exponential one??

 

[hussainb72]

hey guys.
ever since this thread created by soheil an issue has stuck in my mind, is it possible to use a lyulka al-21 in an F-5 structure??
well to start this i should state that an F-5 with AL-21 can achieve a thrust/weight ratio equal to 1.3 .
without doubts it would make it a very agile plane, even better than F-22, SU-35 and EF-2000. after finding out this i was proud of myself and walking around happily and fantasizing a dogfight between F-15 and the mentioned plane or with EF or F-16( ) and then i told myself do not be silly, if it was possible US, Russia and Europeans would do that.
so i started to digging a little bit. i was suspected that maybe the drawback of such design (a heavy engine in a light weight fighter) is the fuel consumption. so i calculated internal fuel to fuel consumption of each fighter jet in an hour interval. the resulting ratio was around 0.3<R<1. the spectrum mentioned consisted of multi roles, interceptors, bombers and strikers. from what i understanded interceptors and strikers have near to 1 ratio, multi roles have <0.5 and bombers similar to multi roles and in some cases less than that. while interceptors and multi roles had thrust/ weight ratio near to 1. while in bombers and strikes case higher T/W is not necessary.
it kinda makes sense, bombers do not need heavy load of fuel as you plan to hit some point on the map before doing it, interceptors need hell lot of fuel to cover their country's air space and they need better T/W ratio to immediately increase their speed and reach the compromised point and obviously to maintain their agility against enemy fighters.
so i come to a conclusion that it does not matter which engine you have, you can make any type of military plane with that to fit your requirement, like soloviev D-30 that powers a fighter, a military cargo and an interceptor. or GE j-79 that powers A-5, F-4 and other military planes.

so lets get back to the F-5 with AL-21 theory and review what we got here:

F-5's internal fuel capacity is almost 2 tons (F-20 tigershark has similar number of 2.3) and each GE J-85 consumes 1.5 tons fuel per hour working at their MAX power. this makes a fuel capacity to consumption ratio of 0.66 . that number for F-20 is 0.6, EF-2000 is 0.5 and 0.57 for dassault rafale. but when you replace two J-85 with a single AL-21 that ratio drops to 0.3 which is a rare number in fighters except of MIG-21 which had the same exact number and that was not really remarkable plane with only 1000 km range.
regarding the physical changes that chaging two J-85 with one AL-21 would bring i mentioned improved T/W ratio, but another issue is that this kind of change will add another 1318 kg to plane and most importantly to the back of it and will cause instability in flight. how ever the empty weight does not change that much compared to tiger shark and the asymmetry of weight could be solved with changing the position of wings position:

View attachment 578160
View attachment 578161

so we see that this change in power plant results in better T/W ratio and worst internal/consumed fuel per hour.
so my question is:
1-no one does this (putting a heavy engine in a light fighter) because the plane would have a very conflicting result like ones in mig-21 that made it excellent regarding agility and disappointing regarding it's range.
2-isn't it possible to operate the AL-21 around 10 kilo newtons (cruising power for an F-5E)?? do the jet engines consume fuel with a linear relationship to the power or an exponential one??

If such a design should be made, the wings should be bigger, which means more fuel, and iran can come up with something similar to the EF 2000 if its going to change the plane's structure. But the intakes should stay in their places and just get bigger a little. by increasing the size of the wings, the plane will have more lift, it will be able to carry more fuel, and carry more external stores, but still be considered as a light weight fighter. But the aircraft might need a fly-by-wire system to control those canards, which increases complexity.

 

[Mithridates]

@gambit
sir can you add anything regarding the feasibility of integrating Lyulka AL-21 to F-5 structure??
another question is that if it's possible for jet engines to work in their 10% of max out put power or not?

 

[TheImmortal]

No money for Air Force let alone a fighter jet r&d program.

F-5 is loved by Iran AF, it is easy to manufacture, it has low titanium requirements compared to modern jets, Iran can reverse engineer the engine on a small scale.

Let’s not continue pointless discussions. F-5 derivatives exist because it’s the best Iran can do with the meager defense budget it has.

As long as Iran is under severe sanctions and IRGC controls the lion share of funds then Iran Air face will continue to weak. Until a philosophy change happens within IRGC or Iran Air Force is able to convince Rahbar of a drive towards domestic fighter jet production then the status quo will continue.

 

[TruthHurtz]

No money for Air Force let alone a fighter jet r&d program.

F-5 is loved by Iran AF, it is easy to manufacture, it has low titanium requirements compared to modern jets, Iran can reverse engineer the engine on a small scale.

Let’s not continue pointless discussions. F-5 derivatives exist because it’s the best Iran can do with the meager defense budget it has.

As long as Iran is under severe sanctions and IRGC controls the lion share of funds then Iran Air face will continue to weak. Until a philosophy change happens within IRGC or Iran Air Force is able to convince Rahbar of a drive towards domestic fighter jet production then the status quo will continue.

A modern day fighter jet program is simply not in Iran's R&D budget. Last time I checked only around 1 billion USD was allocated to the defence industry annually, with the lions share going into missile development. Theoretically it could actually be higher given the involvement of the IRGC in illicit trade across the world, but still not enough to fulfill the monetary requirements of a fighter jet program, particularly a 5th gen one like Qaher.

There has already been discussion on acquiring and license manufacturing (TOT and all) of the SU-30. This was confirmed back in 2016 when Dehghan was DM. It seems like the recent trend of Russian-Iranian defence cooperation points towards this possibility.

 

[hussainb72]

No money for Air Force let alone a fighter jet r&d program.

F-5 is loved by Iran AF, it is easy to manufacture, it has low titanium requirements compared to modern jets, Iran can reverse engineer the engine on a small scale.

Let’s not continue pointless discussions. F-5 derivatives exist because it’s the best Iran can do with the meager defense budget it has.

As long as Iran is under severe sanctions and IRGC controls the lion share of funds then Iran Air face will continue to weak. Until a philosophy change happens within IRGC or Iran Air Force is able to convince Rahbar of a drive towards domestic fighter jet production then the status quo will continue.

It's not the leader who funds the IRGC of the normal army for him to favour any of them over the other. It's the president who has chosen to reduce the budget of both the IRGC and the normal army, and all this money is stolen by him and all the people under him and sent to European banks.