Korea's KF-X: News & Discussion

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(Creating this thread because existing KF-X discussion is highly fragmented.)

Korean media is reporting that the twin-engine C-103 design has been endorsed in a high-level meeting of Korea's Joint Chiefs of Staff, chaired by the Minister of Defense. Bids are expected to be solicited in the coming weeks, with development beginning in earnest by the end of the year.

Defense News

“The JCS formed a task force to review the costs, requirements and development schedules for the KF-X over the eight months,” JCS spokesman Eom Hyo-sik said. “As a result, the task force reached a decision that a twin-engine aircraft is a right choice as it meets future operational needs and can help catch up with neighboring countries’ aircraft development trends.

Given the potential development period for a twin-engine jet, the spokesman said, the KF-X jet’s initial operating capability is to be scheduled for 2025, a two-year delay from the original goal.

So we're probably looking at an aircraft developing between 41,000lb (2xEJ200) and 52,000lb (2xF414EPE) maximum thrust.

On the supposed economic and technical rationale for a twin-engine design, I repost the following from an earlier thread:

The only way I can make sense of the claim that a twin-engine design has better long-term economic feasibility is if ROKAF is thinking ahead to replacing its F-15s also. If KF-X is a single-engine project powered by e.g. F110/232 then using it as the basis of an F-15 replacement is out of the question and this will require another clean-sheet project perhaps even overlapping with KF-X. A twin-engine design in the class of e.g. Typhoon could more readily be scaled up in future, particularly if this is anticipated from the very beginning. Such an evolution could also map onto the otherwise curious notion of internal stores carriage arriving only with KF-X v2.0.

I do wonder about the choice of Lockheed Martin as foreign partner when it comes to building what amounts to direct competitor to LM's own F-35.

Also, I wonder if Japan's recent ATD-X rollout had anything to do with the decision in favour of the more ambitious twin-engine design. ;)

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2 Engines is a very wise choice. Going into the future versions weight creep would mean that a larger single engine would pretty much enslave the aircraft to US F-35 propulsion developments. Staying with a twin engine design, allows them to evaluate multiple engine sources and pick the best growth path suited for their needs.

I do wonder about the choice of Lockheed Martin as foreign partner when it comes to building what amounts to direct competitor to LM's own F-35.

Design for the jet is in the early phases and its going to take many many years for the Jet to reach IOC. The F-35 has a considerably financial backing from the current customer base, and given that it will be the backbone of the US fleet, constant investments in the program are quite secure. With that backdrop I really do not see this particular aircraft threaten the JSF in the future in terms of the program's bottom line anymore than say a fighter that was developed by Korea independent of Lockheed involvement.

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I do wonder about the choice of Lockheed Martin as foreign partner when it comes to building what amounts to direct competitor to LM's own F-35.

To me it is entirely pointless building something that would compete with F-35 whether it were done alone or in association with LM or any other OEM. Much more sensible would be to spend the funds on another project or not spend them at all.

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To me it is entirely pointless building something that would compete with F-35 whether it were done alone or in association with LM or any other OEM. Much more sensible would be to spend the funds on another project or not spend them at all.

Just as F-35 was designed around the United States' unique requirements, KF-X is evidently being designed first-and-foremost around Korea's requirements with export a secondary consideration, and this could well be a wise decision: the export market ain't what it used to be, and most of it will have been gobbled up by F-35 or Gripen E before KF-X could take the stage regardless of configuration.

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Just as F-35 was designed around the United States' unique requirements, KF-X is evidently being designed first-and-foremost around Korea's requirements with export a secondary consideration, and this could well be a wise decision: the export market ain't what it used to be, and most of it will have been gobbled up by F-35 or Gripen E before KF-X could take the stage regardless of configuration.

My comment that I found it pointless building something that would compete with F-35 was not based on export prospects being limited or non-existent (although I think that would almost certainly be the case). I simply do not see the point in re-inventing a wheel that has already been invented by LM. Not only would would KF-X be inferior to F-35, development costs would be very large - perhaps $20 billion to $30 billion. What would be the point of spending so much on KF-X when F-35 would probably do almost everything K-FX could do at a much lower cost?

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The point is to build your own aircraft for both economic and strategic reasons, obviously. And whilst initial versions of KF-X will be inferior to F-35, there's no reason why it couldn't ultimately evolve into a superior platform. I doubt that the Koreans are going to settle for the sluggish performance and uninspiring agility of F-35. As mentioned previously, I suspect ROKAF is thinking long-term with this project to an era of operating a largely indigenous air force centred around KF-X and its descendants. In the long run, there's no reason why they couldn't build their own next-gen engine for it too in partnership with Rolls Royce, GE, etc.

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My comment that I found it pointless building something that would compete with F-35 was not based on export prospects being limited or non-existent (although I think that would almost certainly be the case). I simply do not see the point in re-inventing a wheel that has already been invented by LM. Not only would would KF-X be inferior to F-35, development costs would be very large - perhaps $20 billion to $30 billion. What would be the point of spending so much on KF-X when F-35 would probably do almost everything K-FX could do at a much lower cost?

Spitfire, your estimates on the development cost for the KF-X exceeds various agency's estimates by a factor of 2.

LM itself estimated that a twin-engined KF-X would cost about $10 billion to develop. The Korea Institute for Defense Analysis estimated a twin-engined KF-X to cost $8.3 billion to develop and a single engined KF-X to cost $6.54 billion to develop.

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Aviation Week- SoKo Joint Chiefs want 2 engines for KF-X


The South Korean armed forces have quashed an attempt by Korea Aerospace Industries (KAI) to reduce the cost and technical challenge of the proposed KF-X fighter, with the joint chiefs of staff determining that the indigenous aircraft must have two engines.

The decision raises the stakes for KF-X, the earliest prospective fighter program for Western engine and system suppliers. With a twin-engine design, the program will be ambitious and hard to launch rather than something modest with a more assured future.

South Korea’s air force is already hedging its bets by studying the possibility of importing its next batch of fighters, judging that the KF-X is not likely to go into full-scale development, according to an air force officer quoted by the Segye newspaper in May (AW&ST June 2, p. 29).

..

But the estimate for the twin-engine aircraft is higher than the 6.5 trillion won that the finance ministry has agreed to and lower than Lockheed Martin’s estimate of more than 10 trillion won. This means that the finance ministry, never a fan of the KF-X, may oppose development. It is reluctant to pay more, says the Naeil newspaper. Finance ministry opposition to the 8.5 trillion won program may persuade enough members of parliament not to fund a 2015 launch of full-scale development, which program managers are seeking.

On the other hand, parliament is strongly influenced by its committees. The defense committee under its former chairman opposed KF-X development; now that he has left, it may recommend going ahead with the aircraft. In September, the finance ministry will propose a national budget for the parliament to decide by December.

Meanwhile, the DAPA must conclude negotiations with Indonesia and Lockheed Martin and then choose the prime contractor, which will almost certainly be KAI, since it has experience in combat aircraft development.

Indonesia paid for 20% of pre-development costs and is expected to take the same share of full development. A further 20% is to be borne by industry, including Lockheed Martin, which agreed to support the KF-X in return for South Korea last year choosing the F-35A in the F-X Phase 3 fighter competition. Technology transfer will form part of, maybe most of, Lockheed Martin’s contribution.

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Spitfire, your estimates on the development cost for the KF-X exceeds various agency's estimates by a factor of 2.

LM itself estimated that a twin-engined KF-X would cost about $10 billion to develop. The Korea Institute for Defense Analysis estimated a twin-engined KF-X to cost $8.3 billion to develop and a single engined KF-X to cost $6.54 billion to develop.

Well looking at the past performance of a multitude of national agencies (nevermind Lockheed Martin!) in predicting development costs for weapon systems i would say that spit might have estimated a very belivable numbers... ;)

I'll get me coat

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http://aviationweek.com/site-files/aviationweek.com/files/uploads/2014/07/AW_07_28_2014_2646L.jpg

latest image of the twin-engined KF-X..looks far too much like a twin-engined F-35.

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Intakes are different as well. Plus the initial generation won't have weapon bays, which guarantees different layount, probably a visibly slimmer plane. Then we're bound to see a quite redesigned plane for the next step with the internal weapon bays, but who knows when that will come, probably post 2030.

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It's not a twin engined 35. Simply clever solutions make the design converges toward it.

Glad that it seems they have kept the upper surface simple.

I think they got cornered by the available power of a single engined design. If you want to pack all ( internal offensive Weapon bay, fuel for interdiction etc..) in a single design, the weight factor is limiting your options.

A generic airframe with an adaptable mission pack, that's what they could have gone with (like Japan for example). That way, the design will have remained light enough probably.

Regarding the inlets, it would be interesting to see their own solution. Or wld it be LM?

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http://aviationweek.com/site-files/aviationweek.com/files/uploads/2014/07/AW_07_28_2014_2646L.jpg

latest image of the twin-engined KF-X..looks far too much like a twin-engined F-35.

Looks like the J-31 ! :D

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Too similar to J-31 but just IMHO.

http://images.china.cn/attachement/jpg/site1007/20120928/001372acd0b511cf898a03.jpg

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The most interesting thing about the KF-X is the use of detachable CWB instead of internal bay. This might make sense if the KF-X is significantly smaller than the J-31, I wonder if they will keep it when it grows big enough to accommodate a bay in the belly.

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Didn't knew abt that. Do you have a link that can provide more info ?

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The C-103 design of KF-X, which seems going to be finalised still going for internal bay. Whether the first batch already equiped with this, it's still being discussed.

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The C-103 design of KF-X, which seems going to be finalised still going for internal bay. Whether the first batch already equiped with this, it's still being discussed.

Thx for tho Info

The catapult system for the missiles is strikingly similar to the LM design.

So, we probably have a shallow arrangement for A2A and a bulges one (belly pack?) for A2G. Do I understand right ?

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Thx for tho Info

The catapult system for the missiles is strikingly similar to the LM design.

So, we probably have a shallow arrangement for A2A and a bulges one (belly pack?) for A2G. Do I understand right ?

Well it's early too tell. This drawing of C-103 internal weapons bay design, has been circulated for some time on Korean and Indonesian media and forum. For me, this just show, the design team has reserved internal bay on design, but how to move on this still to early to tell.

The design show LM influenced, wich seems related to ROK choices for F-35. Some in forums speculated (or claimed heard but can not be validated from design team), that they think only shallow internal bay design can be put to C-103, since more bulges one (which can acomodated A to G weapons) is more complicated to adopt with initial C-103 design.

The initial design mock up (from KDN sources) for C-103, did not put internal weapon bay. However looking on the mock up, probably the shallow internal bay can be adopted. Then again, at this time, anything still can be speculated.

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