F-117A Night Hawk

F-117 Night Hawk

Your Captain Speaking
F-117A Night Hawk
Nevada, August 1979. A United States Marine Corps Captain sits behind the controls of a ground-to-air Hawk missile system utilizing powerful radar tracking technology. The Captain is engaged in a war game with Ben Rich of Lockheed Advanced Development Projects, also known as Skunk Works. For Rich, it’s more than a game.

The Air Force is on the fence with respect to his latest program known as Have Blue. Rich decided the war game was not enough to demonstrate his latest invention. To prove his point — he was going to help the Marines, his adversary in this war game, to cheat. He provided the anti-aircraft battery with his plane’s flight plan prior to the game. Soon enough, the radar system positively identified an incoming plane and gave the Marines a moment of satisfaction. Rich would have the last laugh when he explained that they were looking at the chase plane and their target, a prototype of what would become the F-117A Night Hawk, had flown past minutes before.

The $111 million, single seat, twin-engine attack fighter would soon become the first operable stealth aircraft in history. Working off of mathematics developed by Soviet scientist Pyotr Ufimtsev, Skunk Works had written a computer program (appropriately named Echo) to design a faceted airplane that absorbed and deflected radar signals instead of returning them. Ufimtsev published a paper called Method of Edge Waves in the Physical Theory of Diffraction in 1964. Echo came up with an angular and rather unsightly airplane that looked completely unnatural. No sleek aerodynamic lines on this design (later supercomputers would allow for smoothed edges and designs like the B-2). In fact, not even computers could keep such an unstable design airborne. That is, until the late 1970’s. Skunk Works made the contraption fly using quadruple-redundant fly-by-wire control systems.

Ben RichDuring its operational run from 1983 – 2008, the F-117 gave the US a staggering technological advantage. The government didn’t even admit the plane existed until 1988. The plane’s 25-year run of remarkable achievements was no accident. Skunk Works had to overcome a plethora of massive technical challenges to make the plane airworthy. Foremost among the challenges facing Rich’s team was finding the right way to compromise aircraft performance for radar stealth. Every single design decision made on the aircraft was made with stealth in mind. To hide the heat signature of the engines, afterburners were left off the plane and innovative inlet and outlets were created to disperse heat. The wings required a drastically high sweep angle (50-degrees) and thus a very low aspect ratio (the ratio of a wing’s span to its mean chord). Additionally, no radar was allowed on-board to limit the amount of radiation it emitted.

With all of these concessions, the F-117A was not going to win any dogfights. The performance specifications of the plane (45,000′ service ceiling, 2,800-ft climb, 623 miles per hour maximum speed at altitude) would work if and only if the plane could not be detected by radar. With a radar cross-section (RCS) equivalent to some insects (approximately 0.001 square-meters), the Night Hawk accomplished its goals and more. For comparison, the F-16 has an RCS of 5 square-meters.

The stealth F-117A gained notoriety for coming through the Gulf War untouched despite flying approximately 1,300 sorties and almost 7,000 flight hours en route to destroying 1,600 high-value targets. In 25 years, only one F-117A was ever damaged by the enemy. Although still effective, the Night Hawk became an unnecessary expense once the F-22 Raptor was introduced in 2005. It was retired in 2008.

Skunk Works was formed in June, 1943 by the legendary Kelly Johnson. After 32 years of remarkable innovations (including the U-2 and SR-71 Blackbird), Johnson handed the reigns to Skunk Works over to Rich in 1975. Ben Rich made his mentor proud and secured his place in history as the “Father of stealth” thanks to the unconventional yet ground-breaking F-117A Night Hawk.