Boeing Cuts F-15SE Design Feature in Korean Fighter Bid

A flight demonstrator of the Boeing F-15SE Launches a Sidewinder AIM-9X from the conformal internal weapon bay. Photo: Boeing
F-15E with conformal fuel tanks and conventional vertical tail. The F-15SE will be similar to the current configuration, but will feature a conformal weapons bay, instead of the conformal carriage. Other features include improved new cockpit displays, avionics and defensive aids.

As competition to secure a $7.3 billion deal with South Korea for the Asian nation’s next-generation fighter enters its final stages, key “stealth” feature were dropped off Boeing’s F-15 Silent Eagle (F-15SE). Boeing’s F-15SE is in a tough round of evaluations as it competes with Lockheed Martin’s F-35A Lightning II Joint Strike Fighter (JSF) and EADS’ Eurofighter Typhoon to nail down a multi-billion contract with South Korea for as many as 60 fifth-generation fighters.

Back in 2009 Boeing praised the Silent Eagle’s stealth capabilities. Along with conformal weapon’s bay, canted tail fins were key stealth-enhancing features that would go far in reducing the fighter’s radar cross-section (RCS) return while also delivering slightly greater range, and much improved flight characteristics.

The canted tails would also, Boeing claimed, reduce the aircraft’s overall weight. Some industry specialists claim that the tail fins, canted outward 15 degrees, are essential in a stealth fighter design.

And now, Boeing said the canted tail-fin configuration would be offered only as an option and not a standard feature on the F-15SE. According to reports published by the Korean media, wind tunnel tests revealed the canted tail fins delivered only marginal improvement in the aircraft’s performance. (The most significant contribution of the canted tail in reducing radar reflection cannot be tested in wind tunnel)

In response to inquiries from Defense-Update, Boeing responded “Silent Eagle builds on a continuous evolution of capability in the combat-proven F-15 family of aircraft.” The company is “confident that our compliant Silent Eagle offering is best suited to address F-X requirements. Canted Vertical Tails, one of the many capability elements of the Silent Eagle, were offered as an option in our proposal to Korea…” Boeing commented.

Boeing went on to say that “our Silent Eagle offering is best suited to address F-X requirements and provides our ROK customer a highly capable, yet low-risk and affordable Silent Eagle F-X solution on a schedule that will meet the ROK requirements.” As clarification, Boeing insists that development of the canted tail surfaces was not being abandoned or suspended and the company intended to continue development efforts.
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As with all things in life, cost and timely availability are also primary concerns, what makes reducing the developmental risk the F-15SE an advantage, rather than drawback for the Silent Eagle. With The F-35A is still in the developmental stages, the F-22 Raptor cannot be had, the Typhoon is no longer cutting-edge – the Silent Eagle may be the best deal on the table.

The F-15SE flight demonstrator launches an AMRAAM AIM-120 from the conformal internal weapon bay. Photo: Boeing


  1. The Typhoon is still one of if not the best multi role fighters in the world.

    Whilst its not a stealth jet it does have a low radar cross section, it is agile, has an average size weapons payload for a non dedicated stealth aircraft.
    Its also right now in the process of going through the Tranche 3 upgrade so its still cutting edge.

    F15SE is certainly a capable aircraft but it is based on an old design and the SE version is more stealthy than previous versions but its not a dedicated stealth aircraft anymore than the Typhoon is.

    The only reason Boeing even developed the SE was to keep the production line for an ageing design which has plenty of competition now on the global markets.

    The decision on which aircraft the Koreans should buy should also depend on the type of aircraft they want.
    A multi role like Typhoon or F35 or an air superiority fighter in which case they should go with the F15.

    There are also other modern planes avalible like the Raffele or the MIG35 so South Korea is not limited to F35, F15 or Typhoon.

    • The Typhoon is arguably the most overpriced, underdeveloped fighter in existence. It’s only multi-role because Eurofighter powerpoint presentations make that claim. It was hopeless over Libya being almost totally dependent on other platforms for targeting.

      The F-15 just won more export orders from one customer, Saudi Arabia, than Typhoon has in its entire existence.

      The modern derivatives of the F-15 have superior avionics, range, speed and payload than any version in production or planned of the Eurofighter.

  2. If I were South Korea, I would seriously consider numbers v large aircraft in fighting against their most likely enemy…North Korea. F16, the F18, F20’s. Some F15’s were be great for long range missions, but in a quick and dirty mass attack shootout that would happen, it’s going to take numbers against numbers. Spend a lot of money on a few that get overwhelmed/shot down…what’s left to fight with?

    • BpSitRep

      South Korea only has a defense force rather than an offensive military like US has whose job is to go round the world fighting other people’s wars so in this case I would have to agree with you that stealth should not be a priority superior numbers should be.

      Buy quality aircraft but no need to buy the most expensive and fact is the F15SE is more expensive than the standard F15 and there are plenty of better planes out there.
      If cost is the priority rather than hi-tec like the Typhoon then go for something like the F16 again an old design but much cheaper than the top of the line modern aircraft and you stick modern computers into it and you have a very capable plane and of course you can buy two F16s for the price of one Typhoon of F15SE.

      If you want modern jets but on a budget then buy Russianor Chinese and replace the electronics with western ones.

      • Hello Brett

        At $100M (est) per plane, the F-15SE may seem expensive but when all costs vs performance are reviewed, X vs Y vs Z are not the same. The Silent Eagle provides, longer range, bigger weapons payload more powerful AESA / sensor and speed benefits that smaller fighters with low capability albeit less expensive cannot match. To keep the operating costs at or below, you can evaluate an upgraded turbofan engines either the supercruising F100-PW-232 or F110-GE-132 with 2-D or 3-D thrust vectoring nozzles for the advanced F-15s as a consideration.

        Or like you said before, being on a budget buy Russian or Chinese fighters and replace the electronics with western ones. I’d say Sukhoi Su-30MK or Su-35S Super Flanker-E.

        The Su-30 costs approximately US$35 million and the Su-35S costs US$45 million to $65 million (estimated).

        Regards Guest

  3. I like the Silent Eagle concept but object the notion that the Typhoon is not cutting edge. There does needs to be a redesign similar to the Silent Eagle project to modify the airframe to reduce RCS beginning with the air intakes. To be competitive the Typhoon also needs that AESA upgrade finished.

    The Typhoon certainly is not lacking for hard points on which to hang ordnance.

    The airframe is a good design, it just needs updated.

    • I agree that the Eurofighter is a fundamentally good design but as you say it needs a series of expensive upgrades to be competitive; the Eurofighter consortium partners seem extremely reluctant to commit funds to do so. It also doesn’t help that three out of four consortium are buying F-35s while reducing Eurofighter buys. The Eurofighter desperately needs a breakthrough deal like the Saudi F-15SA contract.

  4. Would not buy the F-15SE without the canted tails, why should that be an option if it’s
    essential in a stealth fighter design. Boeing should stop playing games and didn’t the
    Typhoon’s outperform the F-15E’s how would they stack up against the F-15SE’s. The
    canted tails would also Boeing claimed, reduce the aircraft’s overall weight would that
    help F-15SE’s performance?

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