Why the F-117 Has Returned

Few other aircraft have become as iconic as the Nighthawk. The first true stealth aircraft, designed entirely for radar invisibility, remains a testament to American Cold War engineering to this day.

Under the Skunk Works team, Lockheed’s winning entry into the competition was codenamed Have Blue,

For two and a half decades, it would serve in a frontline role, then in 2008, it would be retired. Now, over forty years since its introduction, the aircraft has seemingly been resurrected and is flying again in various roles.

Still largely classified, the Nighthawk faces a unique challenge: it is considered retired from frontline service yet is not fully retired. Currently, the US Air Force plans to keep the aircraft in operation until at least 2034. How did it end up like this? Today, we take a look back at DARPAs project Have Blue, the Nighthawk project itself, and the unconventional missions it has been brought back to fill.

LOCKHEED HAVE BLUE

While we still see the Nighthawk as a relatively modern development, the project dates back to the Vietnam War and emerged alongside most other fourth-generation aircraft as a response to several noted threats.

Throughout the latter half of the conflict, the US military began compiling information on the growing threats faced by pilots. In particular, for third-generation fighters and larger bombers, the primary threat was radar-assisted anti-air. Even in Vietnam’s complex topography, modern Soviet SAMSurface-to-Air Missile: A ground-based or ship-launched guided missile system designed to detect, track, and destroy enemy aircraft, helicopters, crui... More systems were proving increasingly effective.

The 1973 Yom Kippur War would further validate these concerns. Over the span of just under three weeks, the Israelis would lose over 100 aircraft to Soviet-designed anti-air defences. As the Soviets rolled out more advanced integrated defence networks, US analysts believed that the US might suffer similar losses in a war in Europe. In such a scenario, NATO’s air forces would be depleted in just two weeks.

Over the following year, DARPADARPA (Defense Advanced Research Projects Agency): A central research and development agency within the United States Department of Defense (DoD) task... More would approach a number of manufacturers. The goal was to study radar signature reduction and determine whether it was possible to produce a design that would be invisible to radar. Of the five companies approached, only McDonnell Douglas and Northrop would accept the task.

Lockheed had not been approached, but after hearing about the program, Clarence Johnson and the team at Skunk Works were granted CIA clearance to discuss the project with DARPADARPA (Defense Advanced Research Projects Agency): A central research and development agency within the United States Department of Defense (DoD) task... More. Showing great interest, after much debate, the Lockheed team was granted a place in the program, albeit without government funding.

DEVELOPMENT BEGINS

Under the internal designation Have Blue, conceptualisation would begin. Rather than focusing on aerodynamic characteristics, the concept would be developed around the shaping that best minimises the radar signature while remaining aerodynamically competent.

While legendary Skunk Works designer Kelly Johnson was initially sceptical, his successor Ben Rich championed a radical new design. Based on the work of mathematician Denys Overholser, the concept used sharp, flat surfaces at odd angles. This design was deemed more practical; rather than diffusing the signal across a blended surface, flat surfaces at swept angles would simply deflect to prevent return signals.

Furthermore, the faceted design was a necessity, as their ‘ECHO 1’ program could only run accurate simulations on simple, flat surfaces.

Lockheed and Northrop were down-selected for the final phase of DARPA’s XST (Experimental Survivable Testbed) competition. During this phase, they would construct mockups, wooden miniatures, and wind tunnel models, culminating in a radar signature test at the White Sands test facility, where a contract winner would be declared. Using full-scale wooden mockups, Lockheed’s concept would prove more effective.

DARPADARPA (Defense Advanced Research Projects Agency): A central research and development agency within the United States Department of Defense (DoD) task... More encouraged Northrop to keep developing ideas, leading to the start of project Tacit Blue. Its design principles would later influence the B-2’s development.

F-117 DEVELOPMENT

Have Blue would move forward, with the initial working prototype flying in 1977. A promising design, it was small – just a quarter the weight of the later Nighthawk – with a 72-degree swept wing, radar-absorbent coatings and materials, an inverse V tail, and an intake system covered by a specially designed grid, with blow-in doors above that would open during takeoff.

Given the unstable design, the team adopted the quadruple-redundant fly-by-wire flight control system and avionics used to stabilise the F-16.

The result was an aircraft with low observability – both visually and in terms of infrared and radio emissions.

On November 1, 1978, Skunk Works received funding to develop the prototype into a full-fledged stealth bomber, known as the F-117, possibly to obscure the true intent in case of an intelligence leak. The aircraft would be larger and feature several aerodynamic modifications while maintaining the core design principles.

It wouldn’t feature a radar or high-speed capabilities. Rather, to minimise visibility across the spectrum, almost one ton of radar-absorbing materials would be used, alongside various spray-on coatings. With a limited top speed, these materials would keep the aircraft cool and very faint on infrared. Likewise, the IR signature from the exhaust would be minimal, as in the Have Blue design, which helped dissipate heat by spreading the exhaust gas across a thin, non-circular tailpipe.

Regarding armament and target acquisition, the aircraft would, in its initial form, feature IRADS, an infrared acquisition and designation system. Paired with a ring laser gyro INSINS (Inertial Navigation System): A self-contained navigation system used in military aircraft that calculates position, velocity, and orientation wit... More tracked to a moving map system for situational awareness, the pilot could use a wide-angle FLIRForward-Looking Infrared (FLIR) is an airborne or vehicle-mounted thermal imaging system that detects infrared radiation (heat) emitted by objects and... More to acquire a target. This would then be slewed to a narrower downward-looking infrared, boresighted to a laser designator.

Much of the workflow would be handled by three IBM mission computers, similar to those used on the Space Shuttle. Among the tasks handled would be avionics and mission planning, the latter supposedly utilising a pathfinding system to navigate to and from waypoints using computer-calculated routes around input threats.

First flying on June 18, 1981, the Nighthawk would enter service in October 1983, referred to by some as the Black Jet and kept strictly classified.

IN SERVICE

The Air Force would deny the project’s existence for years, with the media referring to the rumoured aircraft simply as the F-19. In reality, the F-117 was considered among the most valuable military assets available, despite having never been tested in a war zone. It was considered for use in Operation El Dorado Canyon in 1986, but was eventually denied. In 1988, the project’s existence would be formally revealed, and in late 1989 it would be used in combat for the first time, flying strike missions over Panama in Operation Just Cause.

As the record shows, the Nighthawk would quickly become an icon. Their first major tasking would become the most iconic, delivering the crucial opening strikes in Desert Storm. Considered the most heavily defended airspace in the world, the Nighthawks would circle Baghdad for some time before releasing weapons on cue and departing unharmed. It was the ultimate test of the platform.

As many are aware, this was followed by several deployments worldwide and a shootdown incident over Serbia in 1999. Ultimately, in 2008, the platform was retired from service, or so it was claimed.

RETIREMENT FROM USE

Some believe that the Serbia incident indicated the aircraft was becoming outdated and nearing obsolescence. However, this is unlikely. The event was caused by a rare combination of factors: the Nighthawk operated without SEADSEAD (Suppression of Enemy Air Defenses): A military operation designed to neutralize, destroy, or temporarily degrade enemy air defense systems to al... More support, mainly due to weather conditions; NATO’s operational security appears to have been compromised, with advance warnings given to strike packages; pilots generally flew predetermined routes, a practice avoided during Desert Storm; and Serbian radar operators employed an unusual tactic with their SA-3 missile system, which was hard to replicate and only effective when the bomb bay doors were open.

In other words, weaknesses may have existed, but similar arguments could be made today regarding newer threats targeting the B-2 or Raptor.

The true reason for the retirement was probably quite complex. In fact, withdrawing from frontline service seems to have been a more nuanced decision, primarily influenced by factors such as cost, maintenance, and mission assignments. A less discussed aspect was its design; similar to the B-2, the Nighthawk was an all-in-one platform. Adding more capabilities would have compromised its stealth features.

Consider other fourth-generation strike fighters as an example of longevity through upgrades. In the 1990s, rapid improvements in targeting and navigation technology were typically made through tape updates and attachments. Strike Eagle crews received the LANTIRN pod, which provided a FLIRForward-Looking Infrared (FLIR) is an airborne or vehicle-mounted thermal imaging system that detects infrared radiation (heat) emitted by objects and... More display on the HUDHUD (Head-Up Display): A transparent display system that presents critical information directly in a user's line of sight, eliminating the need to loo... More, terrain-following radar, and additional upgrades. This was followed by the LITENINGLITENING Targeting Pod: An advanced multi-sensor targeting pod manufactured by Northrop Grumman that provides military aircraft with precision targeti... More pod, which offered enhanced GPS-assisted target acquisition and designation—making system integration and hardware fitting the main challenges.

While the Nighthawk would receive GPSGPS (Global Positioning System): A satellite-based navigation system that provides precise location, velocity, and timing information to military airc... More and other undisclosed upgrades, designers would have to worry not only about systems integration but also about streamlining internal systems to retain functionality without compromising observability. In other words, upgrade programs would be more costly and risk compromising the aircraft’s core strengths.

However, upon retirement, the Nighthawk would face an intriguing situation. Although some components were compromised in Serbia years ago, the aircraft remains highly advanced and still has many undisclosed features. Scrapping it outright would have been an unwise decision.

In 2008, many airframes were transported to the Tonopah Test Range in Nevada and stored in climate-controlled Type 1000 hangars to help preserve them. This setup suggested that the Nighthawk could be reactivated if needed. However, as we now know, the aircraft continued flying.

RETURN TO USE

Between 2010 and 2019, several images emerged, appearing to show the aircraft flying in some capacity over the Mojave Desert, operating predominantly out of public view. Finally, in 2020, the resurrection of the Nighthawk as a testbed and research platform was essentially confirmed, with a spike in operations.

Since then, we have seen the Nighthawk fly more regularly at US Air National Guard bases, at various test ranges, and now, as seems increasingly common, along low-level routes that are open to the public. The result has been some of the highest-quality imagery of the aircraft in flight, with little apparent care for secrecy at this point.

So why has the Nighthawk been resurrected, and what is the plan for its future?

In early 2023, as reported by The War Zone, Nighthawk activity was confirmed to be multi-purpose, with a long future ahead. Some were used as testbeds for next-gen systems, others for research and data collection, and still others as aggressors in exercises. In the latter case, it was reported that this included flying as cruise missiles, apparently due to a similar radar signature.

The report noted that the US Air Force Test Centre had green-lit an unclassified contract to commence in 2024 and run for 10 years, aimed at keeping part of the Nighthawk fleet airworthy. These stated requirements included not only support for standard launch and recovery but also configuration changes and design alterations to existing modifications.

What we do know – as mentioned in several reports – is that the Nighthawk can play a very different adversary to what pilots would usually encounter, and could realistically simulate foreign designs with low observability.

ADVANTAGES OF RETAINING FLEET

Resurrecting the Nighthawk for different R&D or aggressor roles offers several advantages. As mentioned earlier, it can imitate certain foreign stealth aircraft, and it can also be flown to represent smaller targets, like cruise missiles, which it reportedly does in some exercises.

Another lesser-discussed benefit is that the Nighthawk is available in large numbers, with over 40 working airframes, while also being retired from frontline service. This gives engineers a chance to conduct real-world flight tests on a still highly advanced platform, integrating newer experimental systems, without withdrawing aircraft from frontline readiness. In this capacity, the Nighthawk serves as a testbed for new stealth coatings and sensors and a calibration tool for existing radars and sensors.

CONCLUSION

Although the specific details of the research remain classified, visual evidence suggests ongoing experimentation. In 2022, photos emerged showing a Nighthawk aircraft with a reflective coating, similar to coatings seen on F-35s and F-22s, likely used to disrupt infrared sensors. This serves as confirmation that the Nighthawk continues to play a vital role.

Originating from 1970s experiments at Skunk Works, the Nighthawk is expected to serve for another decade in its vital support role. It is still unclear whether Skunk Works has, or will be, tasked with creating a successor. Possibly, the B-21 was meant to fill this role, or perhaps confidence now lies in multirole systems supported by the B-2.

Either way, the Nighthawk remains not only the first true stealth aircraft to enter production but also the most successful on the battlefield.