Why was the F-117 retired? Was it just a transitional technology for Stealth?

The F-117 Nighthawk was a low-visibility stealth bomber that was retired in 2008. The F-117 fighter aircraft was designed in the 1970s and made its first test flight on 11 June 1981. Subsequently, it entered service in 1983. This secret programme was only made public for the first time in 1990, at the end of the Cold War.

Designed in the same years as the F-15 and F-16, the development process of this aircraft took a longer period of time than these fighter jets, it started flight tests later, and therefore entered the inventory later. However, while the F-15 and F-16 are still in use with structural improvements and modernisations, the use of the F-117 was terminated relatively early.

By the 2000s, it was claimed that the F-117 was an obsolete aircraft and vulnerable to advanced air defence systems. The main reason for this was the downing of an F-117 fighter jet over Yugoslavia in 1999 by an old Soviet-made surface-to-air missile (SAM) system. 

In fact, until this shooting down incident, there was a high perception that F-117s were indeed stealth aircraft and could not be shot down. Indeed, the F-117 Nighthawk was designed to reflect radar waves with its very different 'asymmetric' angular design, which is very different from the traditional design concept, and thus to ensure that it does not return to the radar. It was a special fighter aircraft coated with radar absorbing paint. It was described by Lockheed Martin as "virtually invisible to radar". However, this stealth aircraft was unable to resist radar, especially low-frequency radar capable of detecting its general position, and contrary to claims, it was not "virtually invisible to radar".

By the way, the procurement cost of the F-117 was also high. It was an expensive aircraft. It was also difficult to maintain. The biggest factor that caused this difficulty was the need to maintain its low visibility characteristics. A lot of time, human resources and long-lasting maintenance costs had to be incurred in order not to deteriorate the stealth features during maintenance. In addition, the F-117s had to be stored in climate-controlled hangars, and their special coatings had to be checked regularly, and defective coatings had to be repaired and replaced when necessary. The F-117 was also an aircraft that used toxic chemicals that posed a health risk to personnel, causing anxiety among pilots and aircraft maintenance personnel in contact with the aircraft.

Over time, fifth-generation fighter aircraft capable of performing the missions of the F-117s began to enter the inventory of the US Air Force. First the F-22 Raptor and then the F-35 Lightning II have largely eliminated the need for F-117 aircraft. They were also better able to adapt to changing threats and environments than the F-117, which was optimised for a specific mission and scenario. Since these aircraft had better performance, stealth, avionics, sensors, weapons and versatility than the F-117, there was no longer any point or need to keep additional F-117s in the inventory.

Looking at the big picture, until the F-22 and F-35 were developed and entered the inventory, the F-117, as an intermediate aircraft, albeit with lower performance, had accomplished important works. The low visibility feature of this aircraft was not only a transitional technology, but also a revolutionary one. The F-117 was the first operational aircraft to use low visibility technology to evade enemy radar and penetrate heavily defended airspace. It proved its effectiveness in conflicts as diverse as Panama, Iraq, Bosnia, Kosovo and Afghanistan. It also served as an aircraft that inspired these and other countries to develop their own fifth-generation aircraft, such as Russia's Su-57 and China's J-20. It contributed to the development of world military aviation.

The F-117 was an extraordinary aircraft that made history and changed the course of war. It fulfilled its purpose and was retired in 2008, having reached the end of its projected service life. However, it is still remembered by many aviation enthusiasts and experts and is the subject of Hollywood films.

In fact, the F-117 should not be seen as an aircraft that was retired so quickly. It entered service in 1983 and was retired in 2008. This is an average of 25 years for military aircraft. However, at that point, the F-117 was past its prime. It was a first generation stealth aircraft. The F-117 was originally designed to penetrate deep into Soviet airspace and strike strategic targets in the Soviet rear. The aircraft's low visibility characteristics were designed to allow it to strike heavily defended targets in high-intensity operating conditions without fear of being shot down. 

This aircraft, the pride of American technology, was shot down over Serbia in 1999. The US military tried to dismiss it as a "fluke hit", but in reality it was shot down by an anti-aircraft shell. 

Lieutenant Colonel Darrell Patrick "Dale" Zelko, pilot of the downed F-117A aircraft

However, by 2008 it had become clear that Russia and China had at least developed specialised radars capable of tracking this stealth aircraft, if not yet capable of firing missiles directly against it. Moreover, the F-117's low cruising speed and almost complete lack of manoeuvrability meant that it would have little chance of survival if intercepted by enemy fighters guided by ground-based radars.

After the F-22s were put into service, it was decided to replace the F-117 with these aircraft. The F-22 had lower visibility and much better aerodynamic performance. It was faster, more manoeuvrable and had a larger operational radius than the F-117, eliminating the need for the F-117. As a result, the F-22 would have far fewer problems surviving in contested airspace against enemy fighters. Although the F-22's internal ammunition/missile carrying capacity was lower than that of the F-117, defence planners at the Pentagon decided that the F-22's capabilities would be sufficient to sustain the United States until the F-35 entered the inventory, and gave way to the F-117.

In addition, defence planners began to rely on the B-2 to perform many of the missions that the F-117 was undertaking. The B-2 was already designed to be a much lower visibility aircraft than the F-117. It could carry more cargo. It had a longer operational radius, which allowed it to penetrate enemy airspace. The B-2 was originally designed as a nuclear bomber. However, the development of stand-off munitions such as the JDAM allowed the B-2 to also be used as a highly accurate and effective conventional bomber.

Incidentally, the F-117s were certainly designed to penetrate Soviet bloc-controlled airspace, but they were not designed to do so at any strategic depth. As long as the Eastern Bloc countries survived, it was never clear how this stealth bomber would be used to hit targets inside the USSR. As is well known, the Soviet mainland was more than 5,000 miles wide. At the time of its development, the so-called Eastern Bloc countries, now Eastern European countries, were an obstacle for these aircraft, which had an operating radius of about 1,000 miles. As long as the Eastern Bloc remained in place, it was unlikely that these aircraft would be able to strike strategic targets within the Soviet Union. Attacks on targets in depth were the province of strategic bombers, which had a radius of action about five to seven times that of the F-117s. The F-117s never assumed the role of strategic bomber. This was the primary role of the B-52, B-1 and later B-2.

Indeed, the aerodynamics of the F-117 were not great. It did not have high manoeuvrability. This aircraft used a first-generation stealth design that was still under development. It was a point design that worked for the time, but this particular aircraft was not adaptable to other missions or environments. It did what it did well, nothing more.

In addition, it was not a platform for self-improvement, either in terms of avionics (e.g. radar) or engine (intake/exhaust limitations). Improvements that can be made today on the F-15 and F-16 could not be made for this aircraft. No way was found on how to improve and develop the capabilities of the aircraft. The US Air Force was also disturbed to see how easy it was to shoot down F-117s. A simple anti-aircraft shot down the aircraft, destroying its invisibility. Realising that it would not be possible to improve this aircraft, and that a possible improvement programme would be very expensive, the Pentagon was forced to discontinue the use of this aircraft, whose cost-effectiveness was decreasing every year, in 2008. 

With the increasing number of F-22 fighter jets, the US decommissioned the last 58 F-117s in the inventory. The 2008 decision also stipulated that the F-117s could be reactivated if necessary. For this reason, F-117s were kept in a status that could be flown at any time. In 2017, various news appeared in the media that all of these aircraft would be dismantled within 10-15 years. 

Meanwhile, an F-117 was spotted taking off from Nellis Air Force Base in Las Vegas around 15:40 on 30 October 2017. Again, several F-117s landed at Miramar Naval Base. Regarding this flight, the US Air Force said, "The Air Force has retired the F-117 from active service, but pilots at the Air Force Test Centre still fly them for limited research activities." Apparently, the 'ghost' is always kept ready for duty.