The F-47 Program Won’t Be Another ‘F-35’ – On March 21, when United States President Donald Trump awarded Boeing the US Air Force Next Generation Air Dominance (NGAD) program, he commented that testbed aircraft had already been flying for “five years.” More than one curious follower of US military aircraft programs has been asking why the prototypes have been flying for so long before a contractor selection was even made.
There are several reasons why a program of this size and importance would be flying for years before announcing an award. The history of stealthy, high-end platforms involves extensive testing of various concepts and low radar cross section (RCS) on specialized vehicles to validate specific design techniques.
Shown is a graphical artist rendering of the Next Generation Air Dominance (NGAD) Platform. The rendering highlights the Air Force’s sixth generation fighter, the F-47. The NGAD Platform will bring lethal, next-generation technologies to ensure air superiority for the Joint Force in any conflict. (U.S. Air Force graphic)
The forerunner of the famous F-117A Stealth Fighter was a project to develop two prototype aircraft under a classified program called HAVE BLUE. The two vehicles were built at a cost of $37 million for both aircraft. The first flight of these was in early 1978.
The first of 64 production models of the F-117A was then delivered in 1982 to the USAF. Engineers gained a wealth of information from the flights of the HAVE BLUE testbed aircraft. But, the final production version of the F-117A was larger, used a different inlet design, and was powered by a different engine—along with countless other characteristics.
However, the full-scale production line and the subsequent use of the aircraft in combat would never have been possible without the testbed models.
Tacit Blue: A Pure Technology Demonstrator
In the rich history of US combat aircraft design, there are examples of one-off air vehicles built and then flown but never having entered production. Although the HAVE BLUE aircraft greatly resembled the F-117A, they were built to test the design, as the course of stealthy aircraft development is not always straightforward.
From the beginning, other aircraft types are intended as test beds to generate data that could be used to design a completely different kind of platform.
Northrop’s TACIT BLUE test bed vehicle was built decades ago by Northrop Grumman and was a key step in the design of the flying wing B-2 Stealth Bomber. The aircraft flew 135 times over the period 1982-85, sometimes more than once on the same day.
Northrop’s Chief Engineer at the time, John Cashen, described just what a unique animal this vehicle was when he was quoted as saying, “You’re talking about an aircraft that at the time was arguably the most unstable aircraft man had ever flown.”
TACIT BLUE looked nothing like the B-2, making designing and building it possible. It was a single-seat test vehicle often called nicknames like “the Alien School Bus.” It was also the first stealth air vehicle to feature curved surfaces for radar cross-section (RCS) reduction.
Shown is a graphical artist rendering of the Next Generation Air Dominance (NGAD) Platform. The rendering highlights the Air Force’s sixth generation fighter, the F-47. The NGAD Platform will bring lethal, next-generation technologies to ensure air superiority for the Joint Force in any conflict. (U.S. Air Force graphic)
It is also a long time between the end of this air vehicle’s program and the aircraft that became of becoming operational. The B-2 did not begin production until 1987 and did not enter into service officially until 1997 – 12 years after TACIT BLUE flew for the last time.
Not An F-35
Between the two extremes, the F-47 prototypes are part of this legacy of test bed models used to validate specific theories or planforms. The safe bet is that the F-47 aircraft that have been flying for years are probably as close to the aircraft that ends up being built on a production line as the HAVE BLUE vehicles were to the F-117. They are not likely to be another Alien School Bus.
What they decidedly are not is another F-35.
That program has been maligned by many—including Trump advisor Elon Musk—in recent years as having been a complex and costly development process, coupled with its “jack of all trades, master of none” design. No small number of military officials have been more direct and have simply said, “We will never build another aircraft like his ever again—one basic design with three vastly different mission and customer profiles.”
The US Navy has its own distinctly different program for its own 6th-generation fighter called F/A-XX. Reading through the reporting on this program, it is clear the service is calling for the design of an aircraft that is nothing like the NGAD—different design criteria and different propulsion concepts.
As one colleague told me recently, there is no chance these two programs will ever be combined into one single effort, as with the F-35.
About the Author:
Reuben F. Johnson is a survivor of the February 2022 Russian invasion of Ukraine and is now an Expert on Foreign Military Affairs with the Fundacja im. Kazimierza Pułaskiego in Warsaw. He has been a consultant to the Pentagon, several NATO governments and the Australian government in the fields of defense technology and weapon systems design. Over the past 30 years he has resided in and reported from Russia, Ukraine, Poland, Brazil, the People’s Republic of China and Australia.
