Any person who has bought the latest and greatest technological gadget knows the pain. The sheer joy of showing off that slick new piece of kit turns to frustration when its successor is announced.
The F-35 Lightning II is still months away from its IOC, yet the USAF is already looking into future upgrades. Not just minor upgrades, like additional weapons, but major upgrades like radar and engines. Considering the massive amount of PR stating that the F-35 is the most "advanced fighter in the world", one might start to question why the USAF is already planning on the current model becoming obsolete.
The JSF has been criticized for its flaws. It is seen as too heavy, too slow, too expensive, and not that much better than legacy F-16s and F/A-18s it is destined to replace. It is reasonable to assume that the addition of a new, more powerful engine, improved avionics, and even laser weapons would make it more palatable to its critics. After all, who doesn't like more power and lasers?
|GE's ADVENT variable cycle engine.|
This new engine program, known as Adaptive Engine Technology Development (AETD) looks to bring adaptive-cycle engine design to the next generation of combat aircraft, including the LRS-B, F/A-XX, and others.
|Power (top) vs. efficiency (bottom).|
The advantage of a variable-cycle engine is that it improves power while reducing fuel consumption. It does this by varying the turbofan bypass ratio. Current turbofan designs need to compromise between power and efficiency. Low-bypass improves power (think F-22), while high-bypass improves efficiency (think 787). This may be oversimplifying it, but you get the idea. Being able to alter the bypass ratio would allow an aircraft to use less fuel while loitering or cruising, yet allow for more power when needed for combat maneuvers.
The possibility of adding 5-10% more thrust while improving fuel efficiency by 25% would certainly be tempting to F-35 operators.
The big question is: Were F-35 partner nations aware of the planned F-35 upgrades? They are unlikely to be cheap, and it will be a difficult decision to spend even more cash on a politically unpopular program. Worse still, there may be complaints that partner nations were paying for the privilege of "beta testing" the JSF.
With Canada's CF-18 replacement pushed back until the 2020-2025 timeframe, would it be more prudent to see how development of the F-35's upgrades turn out? It may be some time before a "F-35D" becomes available, but it may be worth the wait.