Stealth aircraft are designed to avoid detection using a variety of technologies that reduce reflection/emission of radar, infrared, the F-35 Lightning II, the Chengdu J-20, Stealth is a combination of passive low observable (LO) features and active emitters. LO features encompass the geometric stealth shaping of the aircraft, often using a lambda wing or trapezoidal wing, and radiation-absorbent material. Active emitters consist of low-probability-of-intercept radars, radios and laser designators. These are typically combined with operational measures to minimize the aircraft's radar cross-section (RCS), since common hard turn maneuvers or opening bomb bay doors can more than double a stealthy aircraft's radar return. long wavelength radars, which counter stealth shaping and material focused on shorter wavelength radar, or radar setups with multiple emitters to counter stealth shaping.
Full-size stealth combat aircraft demonstrators have been flown by the United States (in 1977), Russia (in 2000) and China (in 2011). the Chengdu J-20 (2017), the Sukhoi Su-57 (2020), and the Shenyang J-35 (2025) a number of other countries developing their own designs. In-development aircraft include fighters such as the US F-47 and China's J-36, as well as strategic bombers, China's H-20 and Russia's PAK DA. There are also various aircraft with reduced detectability, either unintentionally or as a secondary feature.
Stealth aircraft first saw combat when the F-117 was used in the 1989 United States invasion of Panama. Since then U.S., UK, and Israeli stealth aircraft have seen combat, primarily in the Middle East, while the Russian Su-57 has seen combat in the Russian invasion of Ukraine. In March 2026, during the 2026 Iran war, a stealth fighter first shot down a crewed fighter in combat, when an Israeli F-35I "Adir" downed an Iranian Yak-130 fighter jet over Tehran. , there has been one confirmed shootdown of a stealth aircraft, during the 1999 NATO bombing of Yugoslavia, of a USAF F-117 by a Serbian Isayev S-125 'Neva-M' missile brigade commanded by Colonel Zoltán Dani, while a second incident damaged an F-117. Russia and allegedly China studied the relatively intact wreckage.
Design principles
thumb|Vehicles like this [[Boeing–Sikorsky RAH-66 Comanche|RAH-66 proved challenging to design stealth capabilities for helicopters.]]
Besides all the usual demands of flight, the design of a stealth or low-observability aircraft aims to reduce radar and infrared (thermal) detection, including:
- Reduce thermal infra-red emission from the engine and its exhaust wake
- Reduce radar reflection back to a hostile receiver by shaping the airframe
- Reduce radar reflections from the airframe by the use of radar-absorbent materials (RAM) or radar-transparent materials such as plastics.
- Reduce radar detection from exposed internal surfaces such as the cockpit, weapons bay and engine intake ducting.
The distance at which a target can be detected for a given radar configuration varies with the fourth root of its radar cross-section (RCS). Therefore, in order to cut the detection distance to one tenth, the RCS should be reduced by a factor of 10,000. Size, shape, material composition, radar frequency, polarization, and direction of observation all factor into the amount of energy reflected by a target when illuminated by radar.
Rotorcraft introduce a particular design challenge, due not only to their multiple wing surfaces and articulated joints, but also to the constantly-changing relationship of these to the main airframe surfaces. The Boeing–Sikorsky RAH-66 Comanche was one of the first attempts at a stealth helicopter.
Limitations
thumb|[[Northrop Grumman B-2 Spirit|B-2 Spirit stealth bomber of the U.S. Air Force]]
Instability of design
Early stealth aircraft were designed with a focus on minimal RCS rather than aerodynamic performance. Highly stealthy aircraft like the F-117 Nighthawk are aerodynamically unstable in all three axes and require constant flight corrections from a fly-by-wire (FBW) flight system to maintain controlled flight.
Radar Warning Receivers look for regular pings of energy from mechanically swept radars while fifth generation jet fighters use Low Probability of Intercept Radars with no regular repeat pattern.
Some weapons require that the weapon's guidance system acquire the target while the weapon is still attached to the aircraft. This forces relatively extended operations with the bay doors open.
Such aircraft as the F-22 Raptor and F-35 Lightning II Joint Strike Fighter can also carry additional weapons and fuel on hardpoints below their wings. When operating in this mode the planes will not be nearly as stealthy, as the hardpoints and the weapons mounted on those hardpoints will show up on radar systems. This option therefore represents a trade off between stealth or range and payload. External stores allow those aircraft to attack more targets further away, but will not allow for stealth during that mission as compared to a shorter range mission flying on just internal fuel and using only the more limited space of the internal weapon bays for armaments.
Reduced payload
thumb|In a 1994 [[live fire exercise near Point Mugu, California, a U.S. Air Force B-2 Spirit dropped forty-seven class Mark 82 bombs, which represents about half of a B-2's total ordnance payload in Block 30 configuration.]]
Fully stealth aircraft carry all fuel and armament internally, which limits the payload. By way of comparison, the F-117 carries only two laser- or GPS-guided bombs, while a non-stealth attack aircraft can carry several times more. This requires the deployment of additional aircraft to engage targets that would normally require a single non-stealth attack aircraft. This apparent disadvantage, however, is offset by the reduction in fewer supporting aircraft that are required to provide air cover, air-defense suppression and electronic counter measures, making stealth aircraft "force multipliers".
Sensitive skin
Stealth aircraft often have skins made with radiation-absorbent materials (RAMs). Some of these contain carbon black particles, while some contain tiny iron spheres. There are many materials used in RAMs, however generally the specifics as to the composition of the materials are classified.
In December 2007, SAAB researchers revealed details for a system called Associative Aperture Synthesis Radar (AASR) that would employ a large array of inexpensive and redundant transmitters and receivers that could detect targets when they directly pass between the receivers/transmitters and create a shadow.
In 1916, the British modified a small SS class airship for the purpose of night-time aerial reconnaissance over German lines on the Western Front. Fitted with a silenced engine and a black gas bag, the craft was both invisible and inaudible from the ground, but several night-time flights over German-held territory produced little useful intelligence, and the idea was dropped.
Nearly three decades later, the Horten Ho 229 flying wing fighter-bomber was developed in Nazi Germany during the last years of World War II. In 1983, its designer Reimar Horten claimed that he planned to add charcoal to the adhesive layers of the plywood skin of the production model to render it invisible to radar. This claim was investigated, as the Ho 229's lack of vertical surfaces, an inherent feature of all flying wing aircraft, is also a key characteristic of all stealth aircraft. Tests were performed in 2008 by the Northrop Grumman Corporation to establish if the aircraft's shape would have avoided detection by top-end HF-band, 20–30 MHz primary signals of Britain's Chain Home early warning radar, if the aircraft was traveling at high speed (approximately ) at extremely low altitude—.
Modern origins
thumb|[[F-117 Nighthawk, the first operational aircraft explicitly designed around stealth technology. It used facets for diverting radar.]]Modern stealth aircraft first became possible when Denys Overholser, a mathematician working for Lockheed Aircraft during the 1970s, adopted a mathematical model developed by Petr Ufimtsev, a Soviet scientist, to develop a computer program called Echo 1. Echo made it possible to predict the radar signature of an aircraft made with flat panels, called facets. In 1975, engineers at Lockheed Skunk Works found that an aircraft made with faceted surfaces could have a very low radar signature because the surfaces would radiate almost all of the radar energy away from the receiver. Under a 1977 contract from DARPA, Lockheed built a proof of concept demonstrator aircraft, the Lockheed Have Blue, nicknamed "the Hopeless Diamond", a reference to the famous Hope Diamond and the design's shape and predicted instability. Because advanced computers were available to control the flight of an aircraft that was designed for stealth but aerodynamically unstable such as the Have Blue, for the first time designers realized that it might be possible to make an aircraft that was virtually invisible to radar. The F-22 puts a focus on air superiority, with supercruise, high thrust-to-weight ratio, integrated avionics and stealth capabilities.
On 20 December 1989, during Operation Just Cause in Panama, two United States Air Force F-117s bombed a Panamanian Defense Force barracks in Rio Hato, Panama. In 1991, F-117s were tasked with attacking the most heavily fortified targets in Iraq in the opening phase of Operation Desert Storm and were the only coalition aircraft allowed to operate inside Baghdad's city limits and over its airspace. The F-117 while having sufficient stealth, also had a low visual signature. Even still, if the F-117 was visually acquired, it, like all aircraft, were subject to visual air-to-air interception. This was easily circumvented by flying at night.
thumb|The [[F-22 Raptor, is an American fifth-generation stealth air superiority fighter]]
The U.S., UK, Israel, and Russia are the only countries to have used stealth aircraft in combat. These deployments include the United States invasion of Panama, the first Gulf War, the Kosovo conflict, the war in Afghanistan, the war in Iraq and the 2011 military intervention in Libya. The first use of stealth aircraft was in the U.S. invasion of Panama, where F-117 Nighthawk stealth attack aircraft were used to drop bombs on enemy airfields and positions while evading enemy radar. F-117s flew approximately 168 strikes against Scud-associated targets while accumulating 6,905 flight hours. Only 2.5% of the American aircraft in Iraq were F-117s, yet they struck 40% of the strategic targets, dropping 2,000 tons of precision-guided munitions and striking their targets with an 80% success rate. The aircraft is said to have returned in a damaged condition to Spangdahlem Air Base, The event was later corroborated by another F-117A pilot in 2020; however, the incident remains classified, and only limited details have been disclosed. Russian officials confirmed they had examined the wreckage, contributing to the development of the Sukhoi Su-57 fighter and under development Tupolev PAK DA bomber. China also allegedly purchased wreckage parts, contributing to the Chengdu J-20 fighter. The then-new B-2 Spirit was highly successful, destroying 33% of all Serbian bombing targets in the first eight weeks of U.S. involvement in the war. During this war, B-2s flew non-stop to Kosovo from their home base in Missouri and back.
In the 2003 invasion of Iraq, F-117 Nighthawks and B-2 Spirits were used, and this was the last time the F-117 would see combat. F-117s dropped satellite-guided strike munitions on selected targets, with high success. B-2 Spirits conducted 49 sorties in the invasion, releasing more than 1.5 million pounds of munitions.
Stealth aircraft were used in the 2011 military intervention in Libya, where B-2 Spirits dropped 40 bombs on a Libyan airfield with concentrated air defenses in support of the UN no-fly zone.
From February 2018, Su-57s performed the first international flight as they were spotted landing at the Russian Khmeimim Air Base in Syria. These Su-57s were deployed along with four Sukhoi Su-35 fighters, four Sukhoi Su-25s, and one Beriev A-50 AEW&C aircraft. It is believed that at least 4 Su-57 are deployed in Syria and that they have likely been armed with cruise missiles in combat.
In 2018, a report surfaced noting that Israeli F-35I stealth fighters conducted a number of missions in Syria and even infiltrated Iranian airspace without detection. Another fifth-generation stealth multirole fighter from China, the Shenyang FC-31 is also under flight testing.
Australia operates a fleet of 72 F-35A stealth strike fighters, and is also developing and producing an unmanned stealth aircraft, the MQ-28 Ghost Bat, with Australian industry, Boeing Australia and BAE Australia. The MQ-28 is a Loyal Wingman collaborative combat aircraft, with the aircraft's first flight taking place on 27 February 2021. Eight aircraft (Block 1) were delievered by 2024; more aircraft (Block 2) are in production with some delievered.
On March 4, 2026, during the 2026 Iran war, the Israeli Defense Forces announced that an F-35I "Adir" shot down a Russian-manufactured Iranian Yak-130 fighter jet over Tehran, marking both the first F-35 air-to-air kill, and the first ever air-to-air kill made by a stealth fighter.
List of stealth aircraft
{| class="wikitable sortable"
!Type
!Country
!Class
!Role
!Date
!Status
!No.
!Notes
|-
|Airbus Wingman
|European Union
|UCAV
|Fighter
|2024
|Project
|0
|Germany, Spain
|-
|Airbus LOUT
|Germany
|UAV
|Experimental
|2019
|Project
|0
|Low Observable UAV Testbed
|-
|Airbus Sagitta
|Germany
|UAV
|Experimental
|2017
|Prototype
|1
|
|-
|BAE Systems Corax
|United Kingdom
|UAV
|Experimental
|2004
|Prototype
|
|
|-
|BAE Systems Replica
|United Kingdom
|
|
|1999
|Project
|
|
|-
|BAE Systems Taranis
|United Kingdom
|UCAV
|Attack
|2013
|Prototype
|
|
|-
|BAE Systems Tempest
|United Kingdom
|Supersonic
|Fighter
|
|Project
|
|UK contribution to the Global Combat Air Programme (qv)
|-
|Baykar Bayraktar Kızılelma
|Turkey
|UCAV
|
|2022
|Production
|2
|
|-
|Bell 360 Invictus
|United States
|Rotorcraft
|Experimental
|2019
|Prototype
|
|
|-
|Boeing Bird of Prey
|United States
|Subsonic
|Experimental
|1996
|Prototype
|
|
|-
|Boeing F-47
|
{|
|United States
|}
|Supersonic jet
|Fighter
|
|Prototype
|
|
|-
|Boeing Model 853-21 Quiet Bird
|United States
|Subsonic
|Reconnaissance
|
|Project
|
|Developed from Model 853
|-
|Boeing MQ-25 Stingray
|United States
|UAV
|Experimental
|2019
|Prototype
|
|
|-
|Boeing Australia MQ-28 Ghost Bat
|Australia
|UCAV
|Autonomous fighter AI and loyal wingman
|2019
|Pre-production DT&OE
|8
|
|-
|Boeing X-32
|United States
|Supersonic jet
|Fighter
|2000
|Prototype
|2
|
|-
|Boeing X-45
|United States
|UCAV
|Experimental
|2002
|Prototype
|
|
|-
|Boeing–Sikorsky RAH-66 Comanche
|United States
|Rotorcraft
|Attack
|1996
|Prototype
|2
|
|-
|Chengdu J-20
|China
|Supersonic jet
|Fighter
|2011
|Production
|300+
|
|-
|Chengdu J-36
|China
|Supersonic jet
|Fighter
|2024
|Prototype
|3+
|
|-
|Chengdu WZ-10
|China
|UAV
|
|2014
|Production
|
|
|-
|Dassault nEUROn
|European Union
|UCAV
|Attack
|2012
|Prototype
|
|France, Greece, Italy, Spain, Sweden, Switzerland
|-
|DRDO Ghatak
|India
|UCAV
|
|
|Project
|
|
|-
|DRDO SWiFT
|India
|UCAV
|Experimental
|2022
|Prototype
|2
|
|-
|EADS Mako/HEAT
|International
|Supersonic
|Attack
|
|Project
|
|
|-
|Eurocopter EC-665 Tiger
|European Union
|Rotorcraft
|Attack
|2003
|Production
|180
|France, Germany, Spain
|-
|FCAS (New Generation Fighter)
|European Union
|Supersonic jet
|Fighter
|
|Project
|
|France, Germany and Spain (within FCAS)
|-
|Flygsystem 2020
|Sweden
|Supersonic
|Fighter
|
|Project
|
|
|-
|Global Combat Air Programme
|International
|Supersonic
|Fighter
|
|Project
|
|Merger of UK (BAE Systems Tempest), Japan (Mitsubishi F-X) and Italy
|-
|HAL AMCA
|India
|Supersonic
|Fighter
|
|Project
|
|
|-
|HAL Prachand
|India
|Rotorcraft
|Attack
|2022
|Production
|19
|
|-
|Hongdu GJ-11
|China
|UCAV
|
|
|
|
|
|-
|KAI KF-21 Boramae
|South Korea
|Supersonic
|Fighter
|2022
|Production
|6
|South Korea
|-
|Kratos XQ-58 Valkyrie
|United States
|UCAV
|Experimental
|
|
|
|
|-
|Lockheed F-117 Nighthawk
|United States
|Subsonic
|Attack
|1981
|Production
|64
|
|-
|Lockheed Have Blue
|United States
|Subsonic
|Experimental
|1977
|Prototype
|2
|Developed into F-117
|-
|Lockheed SR-71
|United States
|Supersonic
|Reconnaissance
|1964
|Production
|32
|
|-
|Lockheed Martin F-22 Raptor
|United States
|Supersonic
|Fighter
|1996
|Production
|195
|
|-
|Lockheed Martin F-35 Lightning II
|United States
|Supersonic
|Fighter
|2006
|Production
|1,000+
|A-variant CTOL, B-variant V/STOL, C-variant CATOBAR
|-
|Lockheed Martin RQ-170 Sentinel
|United States
|UAV
|
|
|Production
|20–30
|
|-
|Lockheed Martin X-35
|United States
|Supersonic
|Fighter
|2000
|Prototype
|2
|
|-
|Lockheed Martin X-44 MANTA
|United States
|Jet
|Fighter
|2000
|Project
|
|
|-
|MBB Lampyridae MRMF
|Germany
|Jet
|Fighter
|1987
|Project
|
|
|-
|McDonnell Douglas X-36
|United States
|Subsonic
|Experimental
|1997
|Prototype
|1
|No vertical tail
|-
|McDonnell Douglas A-12 Avenger II
|United States
|Subsonic
|Bomber
|
|Project
|
|
|-
|MH-X Stealthhawk
|United States
|Rotorcraft
|Utility
|
|Top-secret
|
|
|-
|Mikoyan Skat
|Russia
|UCAV
|Attack
|
|Project
|
|
|-
|Mikoyan Project 1.44
|Russia
|Supersonic
|Fighter
|2000
|Prototype
|1
|Initially developed for the MFI project
|-
|Mikoyan LMFS
|Russia
|Supersonic
|Fighter
|
|Cancelled
|
|
|-
|Mikoyan PAK DP
|Russia
|Supersonic
|Fighter
|
|Project
|
|
|-
|Mitsubishi X-2 Shinshin
|Japan
|Supersonic
|Experimental
|2016
|Prototype
|1
|
|-
|NGAD (F/A-XX)
|United States
|Supersonic
|Fighter
|
|Project
|
|Navy's NGAD programme. To replace Navy's F/A-18E/F Super Hornets.
|-
|NGAD (Penetrating Counter-Air (PCA))
|United States
|Supersonic
|Fighter
|
|Project
|
|To replace USAF's F-22 Raptors
|-
|Northrop Tacit Blue
|United States
|Subsonic
|Experimental
|1982
|Prototype
|1
|
|-
|Northrop YF-23
|United States
|Supersonic
|Fighter
|1990
|Prototype
|2
|
|-
|Northrop Grumman B-2 Spirit
|United States
|Subsonic
|Bomber
|1989
|Production
|21
|
|-
|Northrop Grumman B-21 Raider
|United States
|Subsonic
|Bomber
|2023
|Production
|3+
|
|-
|Northrop Grumman RQ-180
|United States
|UAV
|
|
|Production
|
|
|-
|Northrop Grumman X-47A Pegasus
|United States
|UCAV
|Experimental
|2003
|Prototype
|
|
|-
|Northrop Grumman X-47B
|United States
|UCAV
|Experimental
|2003
|Prototype
|2
|
|-
|Ryan AQM-91 Firefly
|United States
|UAV
|Experimental
|
|
|
|
|-
| rowspan="2" |Saab KFS
| rowspan="2" |Sweden
|Supersonic
|Fighter
| rowspan="2" |2023
| rowspan="2" |Prototype
|
| rowspan="2" |Konceptet Framtidens Stridsflyg
|-
|UAV
|Fighter
|
|-
|Shenyang J-35
|China
|Supersonic
|Fighter
|2012
|
|10+
|
|-
|Shenyang J-50
|China
|Supersonic
|Fighter
|2024
|
|
|
|-
|Sukhoi Okhotnik
|Russia
|UCAV
|Experimental
|
|Prototype
|2
|The first S-70 prototype had a non-stealthy circular exhaust.
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