question: How do stealth fighters like the F-22 or F-35 work?
comment: Radar works by sending a radio wave out. The radio wave hits the surface of an object and is reflected back at the radar station. It measures the time it takes for the radio wave it sent to get back and that tell you how far away and in what direction an object is. & #x200B; Most airplanes are made of rounded shapes. So not matter what direction the airplane is facing there is always a part of the plane that can reflect the radar signal back towards the radar station. The stealth airplanes are made up of flat surfaces. When radar hits the flat surfaces the radio waves are not reflected back to the radar station but they are reflected away instead. They also use materials on the surfaces that help absorb the radio waves instead of reflecting them. Stealth airplanes are not 100% invisible there are certain angles that the radar can hit the aircraft and reflect straight back to the radar station so that it can detect it. & #x200B; If you have a reflective ball like a Christmas ornament you can see the process illustrated with light waves instead of radio waves. Because the Christmas ornament is rounded you can see your reflection in the ball no matter what angle the ball is from you. But if you take a flat mirror you can only see your reflection if you are facing the mirror at a very narrow angle.
passages: Section::::Reception.
   There is ongoing research to apply track-before-detect across sensor fusion in the core CPU to allow fifth-generation fighters to engage targets that no single sensor has by itself detected. Probability theory is used to determine "what data to believe, when to believe and how much to believe".
  
  These sensors produce too much data for the onboard computers to fully process so sensor fusion is achieved by comparing what is observed against preloaded threat libraries that contain known enemy capabilities for a given region. Items that do not match known threats are not even displayed.
  
  Section::::Common design elements.:Limits of stealth.
   BULLET::::- F/A-18E/F Super Hornet – The F/A-18E/F's radar cross section was reduced greatly from some aspects, mainly the front and rear. RCS to about 20 dB lower as a F18 C/D
  
  BULLET::::- Northrop YB-49
  
  BULLET::::- Scaled Composites 401 – obvious stealth shaping plus composite materials
  
  BULLET::::- Messerschmitt Me 163B – Rocket-powered point defense interceptor aircraft.
  
  BULLET::::- Horten Ho 229 – Flying wing design and partially buried engines may have given a low RCS
  
  BULLET::::- Sukhoi Su-35 - Radar absorbent material on the engine inlets and compressor to halve its RCS
  
  BULLET::::- Tupolev Tu-160M2
   BULLET::::- Ryan AQM-91 Firefly engine on top of fuselage, fuselage with radar absorbent material, flat bottom and sloped sides, canted vertical stabilizers to conceal the exhaust stream.
  
  BULLET::::- Ryan Model 147 various RCS reduction measures, see article
  
  BULLET::::- CASC CH-7 obvious stealth shaping
  
  BULLET::::- CH-805 Flying wing target drone, RCS of 0.01 square meters, for simulating stealth aircraft
  
  BULLET::::- CK-20
  
  BULLET::::- CASIC Sky Hawk Tian Ying Flying wing version
  
  BULLET::::- FL-71 obvious stealth shaping
  
  BULLET::::- Sharp Sword – Shenyang Aircraft Corporation
  
  BULLET::::- Star UAV System Star Shadow obvious stealth shaping
  
  BULLET::::- Wind Blade – Shenyang Aircraft Corporation
   The combination of stealthy airframes, stealthy sensors, and stealthy communications is designed to allow fifth-generation fighters to engage other aircraft before those targets are aware of their presence. Lt. Col. Gene McFalls of the USAF has said that sensor fusion will feed into inventory databases to precisely identify aircraft at a distance.
   BULLET::::- Dassault Rafale – RCS to about 0.20–0.75 m2
  
  BULLET::::- Eurofighter Typhoon – RCS to about 0.25–0.75 m2
  
  BULLET::::- HAL Tejas – Incorporates high degree of composites and radar absorbent material and a Y-duct inlet that shields the engine compressor face from probing radar waves.
  
  BULLET::::- Mitsubishi F-2– composite materials for reduced RCS
  
  Section::::List of stealth aircraft.:Unmanned reduced RCS designs.
  
  BULLET::::- Boeing Airpower Teaming System
  
  BULLET::::- Boeing MQ-25 Stingray
  
  BULLET::::- Boeing X-45 – Boeing, based on the manned Boeing Bird of Prey demonstrator (technology demonstrator)
  
  BULLET::::- General Atomics Avenger
   BULLET::::- X-35 – JSF winning contender developed into F-35 Lightning II
  
  BULLET::::- X-32 – JSF losing contender
  
  BULLET::::- MiG 1.44 – Russian 5th generation fighter prototype
  
  BULLET::::- Sukhoi Su-47 – Russian technology demonstrator
  
  BULLET::::- Sukhoi T-50 - Prototype versions of the Su-57
  
  BULLET::::- Mitsubishi X-2 – Mitsubishi Heavy Industries
  
  Section::::List of stealth aircraft.:Manned.:Accidental or secondary function reduced cross section designs.
  
  BULLET::::- B-1B Lancer – RCS to about 1.0 m2
  
  BULLET::::- Boeing F-15SE Silent Eagle
  
  BULLET::::- F-16C/D and E/F Fighting Falcon – from Block 30 has got reduced RCS to about 1.2m
   BULLET::::- Mikoyan MiG-31(8TK)
  
  BULLET::::- MiG-29/35 (OLS-29/35)
  
  BULLET::::- Sukhoi Su-57 (101KS-V)
  
  BULLET::::- F-15SG F-15SG Eagle (Singapore variant)
  
  BULLET::::- Saab JAS 39 Gripen E/F (Selex ES Skyward-G)
  
  BULLET::::- Eurofighter Typhoon (EuroFIRST PIRATE)
  
  BULLET::::- Grumman F-14 Tomcat (AN/AAS-42 IRST)
  
  BULLET::::- Boeing F-15K Slam Eagle
  
  BULLET::::- Boeing F-15SA Advanced Eagle
  
  BULLET::::- Boeing F-15QA Advanced Eagle
  
  BULLET::::- Lockheed Martin F-16 E/F Block 60/62 (AN/AAQ-32 IFTS)
  
  BULLET::::- Boeing F/A-18E/F Super Hornet (Block III)
  
  BULLET::::- Lockheed Martin F-35 Lightning II AN/AAQ-37 electro-optical Distributed Aperture System (DAS) with a 360 degree IRST, missile detection/warning, and day/night vision capabilities, designed and produced by Northrop Grumman Electronic Systems.
   Stealth aircraft will continue to play a valuable role in air combat with the United States using the F-22 Raptor, B-2 Spirit, and the F-35 Lightning II to perform a variety of operations. The F-22 made its combat debut over Syria in September 2014 as part of the US-led coalition to defeat ISIS.
   Stealth aircraft
  
  Stealth aircraft are designed to avoid detection using a variety of technologies that reduce reflection/emission of radar, infrared, visible light, radio frequency (RF) spectrum, and audio, collectively known as stealth technology. Well-known modern examples of stealth of U.S. aircraft include the United States' F-117 Nighthawk (1981–2008), the B-2 Spirit, the F-22 Raptor, and the F-35 Lightning II.
   In circulation control, near the trailing edges of wings, aircraft flight control systems are replaced by slots which emit fluid flows.
  
  Section::::List of stealth aircraft.
  
  BULLET::::- F-117 Nighthawk
  
  BULLET::::- B-2 Spirit
  
  BULLET::::- F-22 Raptor
  
  BULLET::::- F-35 Lightning II
  
  BULLET::::- J-20
  
  BULLET::::- Su-57
  
  Section::::List of stealth ships.
  
  BULLET::::- "Independence"-class littoral combat ship
  
  BULLET::::- "La Fayette"-class frigate
  
  BULLET::::- "Skjold"-class corvette
  
  BULLET::::- "Tuo Chiang"-class Stealth Corvette
  
  BULLET::::- Type 055 destroyer
  
  BULLET::::- "Zumwalt"-class destroyer
  
  Section::::See also.
  
  BULLET::::- Horten brothers – German engineers whose planes were the models for the stealth bombers.
  
  BULLET::::- Multi-spectral camouflage
   BULLET::::- JH-XX – Shenyang Aircraft Corporation - supersonic medium-range strike bomber to replace the JH-7.
  
  BULLET::::- Project-AZM - Pakistan Aeronautical Complex / Chengdu Aircraft Corporation
  
  BULLET::::- AMCA – ADA / HAL
  
  BULLET::::- B-21 Raider – Northrop Grumman
  
  BULLET::::- - BAE Systems Tempest
  
  BULLET::::- Flygsystem 2020 – Saab
  
  BULLET::::- HESA Shafaq – HESA / IAMI
  
  BULLET::::- KAI KF-X - Korea Aerospace Industries / Indonesian Aerospace
  
  BULLET::::- - New Generation Fighter – Tornado/Rafale replacement by Dassault Aviation and Airbus Defense and Space
  
  BULLET::::- TAI TFX – Turkish Aerospace Industries
  
  BULLET::::- Canceled
  
  BULLET::::- A-12 Avenger II – McDonnell-Douglas / General Dynamics
   Reduced radar cross section is only one of five factors the designers addressed to create a truly stealthy design such as the F-22. The F-22 has also been designed to disguise its infrared emissions to make it harder to detect by infrared homing ("heat seeking") surface-to-air or air-to-air missiles. Designers also addressed making the aircraft less visible to the naked eye, controlling radio transmissions, and noise abatement.
   Section::::Background.:Modern era.
   Boeing unveiled an updated F/A-XX sixth-generation fighter concept in April 2013. The concept is a tailless twin-engine stealth fighter available in manned and unmanned configurations. It has canards, which usually compromises the frontal radar cross-section, but the lack of a tail shows an emphasis on all-aspect stealth. It also has diverterless supersonic inlets similar to the F-35. The manned version seems to have restricted rearward visibility without the aid of a sensor.
  
  Section::::Program Timeline.
   On 17 March 2009, Boeing first displayed an F-15SE demonstrator. The F-15SE was designed to use fifth-generation fighter technology, such as radar-absorbing materials, to significantly reduce its radar cross-section (RCS). It would have possessed a level of stealth that the U.S. government would have allowed for export, being optimized for air-to-air missions (against X-band radars) and much less effective against ground radars (which use other frequencies). Different levels of RCS reduction were studied, and Boeing stated that this stealth will only be in the range of fifth-generation aircraft such as the F-35 Lightning II from the frontal aspect.
   BULLET::::- Kratos XQ-222 Valkyrie Low-Cost, Attritable Strike Unmanned Air System Demonstration (LCASD) trapezoidal fuselage with a chined edge, V-tails, and an S-shaped air intake
  
  BULLET::::- LoFLYTE (Low Observable Flight Test Experiment)
  
  BULLET::::- Lockheed Martin Minion (RCS smaller than F-22 or F-35)
  
  BULLET::::- Lockheed Martin Polecat
  
  BULLET::::- Lockheed Martin RQ-170 Sentinel – Lockheed Martin
  
  BULLET::::- Lockheed Martin X-44 (UAV)
  
  BULLET::::- Northrop Grumman RQ-180 – Northrop Grumman
  
  BULLET::::- Northrop Grumman X-47B – Northrop Grumman (technology demonstrator)
   BULLET::::- MBB Lampyridae – West German stealth fighter prototype
  
  BULLET::::- FMA SAIA 90 – Multirole fighter
  
  BULLET::::- Horten H.XVIII - Horten brothers
  
  BULLET::::- IML Addax – New Zealand multi role fighter prototype
  
  BULLET::::- Novi Avion – Yugoslav prototype, designed to have a features to lower its RADAR cross section
  
  BULLET::::- Technology demonstrators
  
  BULLET::::- Boeing Bird of Prey – Boeing
  
  BULLET::::- Have Blue – Lockheed
  
  BULLET::::- McDonnell Douglas X-36
  
  BULLET::::- Northrop Tacit Blue – Northrop
  
  BULLET::::- Northrop XST – stealth technology demonstrator
  
  BULLET::::- YF-22 – Developed into F-22 Raptor
  
  BULLET::::- YF-23 Black Widow II – Northrop / McDonnell Douglas prototype
   Another important factor is internal construction. Some stealth aircraft have skin that is radar transparent or absorbing, behind which are structures termed reentrant triangles. Radar waves penetrating the skin get trapped in these structures, reflecting off the internal faces and losing energy. This method was first used on the Blackbird series: A-12, YF-12A, Lockheed SR-71 Blackbird.
   BULLET::::- Several helicopters, such as the HAL Light Combat Helicopter and Eurocopter Tiger, are said to feature presence-reduction measures or "stealth". The use of advanced composite materials on the airframe has commonly resulted in reductions in an aircraft's radar cross-section (RCS). In the case of the Eurocopter Tiger, measures were taken to produce minimal visual, radar, infra-red and acoustic signatures to improve battlefield survivability. HAL's Light Combat Helicopter is reported to feature a digital camouflage system.
  
  Section::::See also.
  
  BULLET::::- Stealth aircraft
  
  BULLET::::- Black helicopters
  
  BULLET::::- Unmanned aerial vehicle
  
  Section::::References.
  
  Section::::References.:Bibliography.
   In addition to reducing infrared and acoustic emissions, a stealth vehicle must avoid radiating any other detectable energy, such as from onboard radars, communications systems, or RF leakage from electronics enclosures. The F-117 uses passive infrared and low light level television sensor systems to aim its weapons and the F-22 Raptor has an advanced LPI radar which can illuminate enemy aircraft without triggering a radar warning receiver response.
  
  Section::::Measuring.
   Perhaps the most novel technology introduced for combat aircraft was "stealth", which involves the use of special "low-observable" (L-O) materials and design techniques to reduce the susceptibility of an aircraft to detection by the enemy's sensor systems, particularly radars. The first stealth aircraft introduced were the Lockheed F-117 Nighthawk attack aircraft (introduced in 1983) and the Northrop Grumman B-2 Spirit bomber (first flew in 1989). Although no stealthy fighters per se appeared among the fourth generation, some radar-absorbent coatings and other L-O treatments developed for these programs are reported to have been subsequently applied to fourth-generation fighters.
   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. In May 2018, Major General Amikam Norkin of IAF reported that Israeli Air Force F-35I stealth fighters carried out the first ever F-35 strike in combat over Syria.
   The first combat use of purpose-designed stealth aircraft was in December 1989 during Operation Just Cause in Panama. On 20 December 1989, 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 jets allowed to operate inside Baghdad's city limits.
  
  Section::::General design.
   Section::::Design considerations.:Stealth technology.
  