Lockheed F22 Raptor The Definition of Stealth.

- Introduction

The super-fighter for the 21st century F22 Raptor is worlds first fifth generation fighter aircraft. The first to employ stealth, supersonic cruise, agility and advanced integrated avionics into one single aircraft, it currently dominates the skies over battlefield and bring unequaled capability into the hands of US Air Force fighter pilots.


The high cost of the aircraft, a lack of clear air-to-air missions due to delays in Russian and Chinese fighter programs, a ban on exports, and development of the more versatile and comparatively lower cost F-35 led to the end of F-22 production. A final procurement tally of 187 operational production aircraft was established in 2009 and the last F-22 was delivered to the USAF in 2012.

Lockheed Martin, Boeing and Pratt & Whitney have joined with the U.S. Air Force to develop and produce the revolutionary F-22. The world’s first stealth air-to-air fighter, the F-22 is mostly unseen and deadly at long range and unmatched at close-in dog fighting. As a true multi mission fighter, it has superb, precision-strike ground attack capability. A multimode electronically scanned radar, internal weapons carriage, vectored thrust and a sophisticated fully integrated sensor array are only some of the revolutionary advantages that Raptor brings to the air combat arena.


The F-22 has the ability to super cruise – flying at supersonic speeds without the use of afterburners. The Raptor achieves this by combining efficient aerodynamic design with two Pratt & Whitney F119-PW-100 engines, rated in the 35,000-lb thrust category.

When the cold war at it's peak. The USAF got worried out of the new Sukhoi Su 27 and Mikoyan MiG 25. The USAF sought a replacement to its F 15. A futuristic aircraft that would combat any Soviet design being derived from Su 27 and MiG 25. Just one single airframe that can first see ! first shoot ! and first kill !. Having their previous experiences with the stealth optimised U 2 spy plane and F 117 night hawk. The Americans planned stealth as the basic principle for the next generation fighter aircraft.

The USAF in 1981 developed a requirement for an Advanced Tactical Fighter (ATF) as a new air superiority fighter to replace the F-15 Eagle and F-16 Fighting Falcon. Code named “Senior Sky“, this program was influenced by the emerging worldwide threats, including development and proliferation of Soviet Su-27 “Flanker”- and MiG-29 “Fulcrum”-class fighter aircraft. It would take advantage of the new technologies in fighter design on the horizon, including composite materials, lightweight alloys, advanced flight control systems, more powerful propulsion systems, and stealth technology. The request for proposals (RFP) was issued in July 1986 and two contractor teams, Lockheed/Boeing/General Dynamics and Northrop/McDonnell Douglas, were selected on 31 October 1986 to undertake a 50-month demonstration phase, culminating in the flight test of two technology demonstrator prototypes, the YF-22 and the YF-23.

Each design team produced two prototype air vehicles, one for each of the two engine options. The Lockheed-led team employed thrust vectoring nozzles on YF-22 for enhanced maneuverability in dogfights.

After the flight test demonstration and validation of the prototypes, on 23 April 1991, Secretary of the USAF Donald Rice announced the YF-22 as the winner of the ATF competition. The YF-23 design was considered stealthier and faster while the YF-22 was more maneuverable.

-Design

The Raptor features clipped delta wings with a reverse sweep on the rear, four empennage surfaces, and a retractable tricycle landing gear. Flight control surfaces include leading and trailing-edge flaps, ailerons, rudders on the canted vertical stabilizers, and all-moving horizontal tails; these surfaces also serve as speed brakes.


The F-22's wings, which function as fuel tanks, have undergone a series of pressure tests to ensure they are leak proof. Boeing applied several advanced manufacturing processes to build the wings, which are made primarily of titanium and composites.The wings of the F-22 are the so-called large area clipped delta type, being efficient at high speed. The wings have large leading edge flaps, which make the aircraft capable of also being efficient at low speeds and to enable it to reach extreme Angles of Attack (AOT) of over 60 degrees.

The Era of Third Generation Fighter Aircraft was the era of dedicated role combat aircraft. Some aircrafts were designed solely for the purpose of Interception. While some of them solely for bombing. The era of Fourth Generation aircrafts was the era of Multirole capability , wherein one single aircraft can be assigned different combat roles. But tactically important non combatant roles like aremed reconaissance, Electronic Attack still needed different dedicated aircraft. The Fifth generation era is the era of Omnirole aircraft. One single aircraft could be capable of all sorts combat roles even anti-ship roles amd non combatant tactical roles also.

The welded booms of the aft fuselage are extremely weight-efficient and reduce the use of traditional fasteners by approximately 75 percent Most of the structural loads are absorbed by 5 titanium bulkheads in the middle section of the F-22 (shown black here). The largest one has a dimension of 16 ft by 6 feet, weighing 149 kg (329 lb).The fins are located at the back end of the plane and when viewed from the side, the large fin blocks the heat radiation of the aircrafts engine exhausts as well as any radar search scan.


The surfaces and edges are positioned on the F-22 in groups. The horizontal aileron edges are aligned parallel with the main wings, as well as the fins which are angled the same as the sloped body sides of the plane looked at from the front.The vertical fins contain besides the steering rudders, several antenna's and sensors, used by the avionics for target acquisition as well as communications .The air intakes are located to the sides of the narrower part of the fighter's nose. The inner tubes, where gas and liquid flow, curves inward then upward, to cover the front part of the engine. Looking at the F-22 from the front, the face of the engine is completely invisible dramatically decreasing the chance of radar detection.

How an aircraft is made stealth and how is it designed to be low observable on radar. To know read a detailed article. Click on the link below.

Secrets of Stealth

Computerized flight control system and full authority digital engine control (FADEC)make the aircraft highly departure resistant and controllable. The Raptor’s relaxed stability and powerful thrust-vectoring engines enable the aircraft to turn tightly and perform very high alpha (angle of attack) maneuvers such as the Herbstmaneuver(J-turn) and Pugachev’s Cobra. The aircraft is also capable of maintaining over 60° alpha while having some roll control.

Because of having superior radar system and superior accuracy than legacy Fourth Generation Fighters. The F 22 naturally requires less weapons to carry with itself. Thus the decreased weapon storage capacity in stealth mode against large weapon carrying capability of big fourth generation aircrafts is still not a negative factor.

-Production

Lockheed Martin in Marietta constructs the forward fuselage, the fins, flaps, ailerons and front-end flaps and for mating the three major fuselage components. In fortworth they build the Mid Fuselage. This is the largest and most complex of the F-22 assemblies. It is approximately 17 feet long, 15 feet wide, and six feet high and weighs about 8,500 pounds as shipped. Most of the wiring and tubing for the aircraft subsystems is integrated here. While Boeing builds the Aft fuselage, main wings, power supplies, auxiliary power units, auxiliary power generation systems, airframe-mounted accessory drives and the fire-protection system. Boeing oversees the aircraft's environmental control system and fuel, electrical, hydraulic and engine subsystems. A completed aft fuselage weighs 5,000 pounds and measures 19 feet long by 12 feet wide. The aft fuselage is 67 percent titanium, 22 percent aluminum and 11 percent composite by weight.

The F-22 program also heralds the first application of titanium castings in the aircraft primary structure. Using an advanced process that involves subjecting castings to intense heat and pressure in an autoclave, the F-22 team was able to cast multiple complex shapes as a single high-strength titanium structure. The process avoids weight by eliminating mechanical joints and reduces material costs and machining time. Laser-guided precision drilling eliminates expensive tooling, ensures quality and eliminates the costly rework associated with manual drilling.

The wings are the first to contain spars produced by resin-transfer molding (RTM), an advanced process for manufacturing complex composite parts that reduces cost and improves quality and consistency. Also, the spars use a corrugated "sine-wave" design that makes them stronger and lighter than the traditional "I-beam" design. The wings, along with the first F-22 rear fuselage, herald industry's first use of an automated, laser-guided drilling machine. Developed by Boeing, the system uses lasers with a targeting feature and automated data feedback software to guide the drill exactly to the correct location before drilling. It does so by measuring the relative position of the drill to the structure and automatically making positional adjustments. Holes are drilled to within .007-inch tolerance of engineering specifications and their location, size and depth are controlled by engineering data fed into a computer. Operated by machinists, the system drills about 7,000 holes in each wing. The holes are used for wing-skin, fairing and door attachments.

-Avionics

The F-22's avionics and software system were the most advanced ever integrated into an aircraft when it was inducted. It is the first aircraft to use integrated avionics, where the radar, weapons management system and electronic warfare system work as one, giving the pilot unprecedented situation awareness.

Most fighters currently in use do have similar sensing capabilities and subsystems as used for the F-22, although these fighters avionics have a so-called federated systems architecture. This means that each avionics function has its own processor and essentially works independently. This makes the pilot the integrator of data and the manager of all the supporting subsystems, distracting him/her from more relevant tasks during air-combat. The F-22 avionics concept however, integrates all of the various systems like radar, communications, navigation, identification, electronic warfare, stores management, sensor control and the displays that are the primary means of communication with the pilot.

The package of avionics include BAE Systems EI&S AN/ALR94 radar warning receiver (RWR), Lockheed Martin AN/AAR-56 infrared and ultraviolet Missile Launch Detector (MLD) and Northrop Grumman AN/APG-77 active electronically scanned array (AESA) radar. The MLD features six sensors to provide full spherical infrared coverage. The capabilities if these avionics are explained here. These unique avionics are one of a kind and provide an edge to F 22 over it's adversaries who dies not possess such capabilities.

1 Northrop Grumman AN / APG -77 AESA Radar.


The radar featuresalow-observable, active aperture, electronically scanned array that can track multiple targets under any weather conditions. Radar emissions can also be focused to overload enemy sensors as an electronic-attack capability. The radar changes frequencies more than1,000 times per second to lower interception probability and has an estimated range of 210 km. though planned upgrades will allow a range of 400 km or more in narrow beams.

This radar system can sometimes identify targets “many times quicker than the AWACS”. The IEEE 1394B bus developed for the F-22 was derived from the commercial IEEE 1394 “FireWire” bus system. In 2007, the F22’s radar was tested as a wireless data transceiver, transmitting data at 548 megabits per second and receiving at gigabit speed, far faster than the Link 16 system.

to know more about this awesome radar, its different modes click on the button below.

AN/APG 77 RADAR MODES

2 Computer Integrated Processor CIP


Radar information is processed by two Raytheon Common Integrated Processor (CIP)s, each capable of processing up to 10.5 billion instructions per second. In a process known as sensor fusion, data from the radar, other sensors, and external systems is filtered and combined by the CIP into a common view, reducing pilot workload.


The Hughes-built Common Integrated Processor (CIP) is the 'brain' of the avionics system. The CIP, which is quite literally the size of a oversized bread box, supports all signal and data processing for all sensors and mission avionics. There are two CIPs in each F-22, with 66 module slots per CIP. They have identical backplanes, and all of the F-22's processing requirements can be handled by only seven different types of processors. Currently, 19 of 66 slots in CIP 1 and 22 of 66 slots in CIP 2 are not in use and can be used for future growth.

Each module is limited by design to only 75 percent of its capability, so the F-22 has thirty percent growth capability with no change to the existing equipment. There is space, power, and cooling provisions in the aircraft now for a third CIP, so the requirement for a 200 percent avionics growth capability in the F-22 can be met easily.


CIP also contains mission software that uses tailorable mission planning data for sensor emitter management and multisensor fusion; mission-specific information delivered to system through Fairchild data transfer equipment that also contains mass storage for default data and air vehicle operational flight programme; General purpose processing capacity of CIP is rated at more than 700 million instructions per second (Mips) with growth to 2,000 Mips; signal processing capacity greater than 20 billion operations per second (Bops) with expansion capability to 50 Bops.CIP contains more than 300 Mbytes of memory with growth potential to 650 Mbytes.

3 BAE Systems EI&S AN/ALR 94 radar warning receiver (RWR)


The RWR is a passive radar detector with more than 30 antennas blended into the wings and fuselage for all-round coverage. The most technically complex piece of equipment on the aircraft. The range of the RWR (250+ nmi) exceeds the radar’s, and can cue radar emissions to be confined to a narrow beam (down to 2° by 2° in azimuth and elevation) to increase stealth. Depending on the detected threat, the defensive systems can prompt the pilot to release countermeasures such as flares or chaff. The ALR-94 can be used as a passive detection system capable of searching targets and providing enough information for a radar lock on. The RWR also pics up signals of enemy navigation systems being interfaced. Enemy's ground interface links and even enemy's data links.

4 Lockheed Martin AN/AAR-56 infrared and ultraviolet Missile Launch Detector (MLD)


Lockheed Martin’s AN/AAR-56 Missile Launch Detector (MLD) is a mature, affordable, defensive system capable of providing long-range detection and declaration of both airborne and surface-launched threats. An MLD shipset for each aircraft is comprised of six sensors, three common interface processing cards, and six low observable window frame assemblies. Currently in production for the U.S. Air Force, the MLD is suited to high speed, fixed-wing aircraft. PD079-163 Top view of digital signal processor MLD integrated onto F-22 Window frame assembly PD079-164 PD079-165 An established and tested algorithm provides maximum performance that matches the aircraft platform mission with threat environment. Lockheed Martin continues to advance the modular design of MLD with the development of both high resolution and multi-spectral sensors and an expanded algorithm that incorporates situational awareness and defensive Infrared Search and Track (IRST).

Features

• IR staring focal plane sensors for long range threat detection and declaration

• Low observable windows for improved survivability

• State-of-the-art image processing

• Real-time threat warning

• Mature missile detection algorithms

• On-camera rate sensors for improved threat tracking

• Two-level maintenance for reduced life cycle cost

• Modular design for technology refresh

5. Communication Navigation Identification.


The F-22's Communications/Navigation/Identification (CNI) 'system' is really a collection of communication, navigation, and identification functions, once again employing the CIP for signal and data processing resources. Each CNI function has its associated aperture installed throughout the aircraft.

Boeing 757-200 F-22 Avionics testbed, N757A. The aircraft was used as a testbed for CNI and various other avionics.

6. Inter / Intra-Flight Data Link (IFDL)


Included in the CNI system is an Inter/Intra-Flight Data Link (IFDL) that allows all F-22s in a flight to share target and system data automatically and without radio calls. One of the original objectives for the F-22 was to increase the percentage of fighter pilots who make 'kills'. With the IFDL, each pilot is free to operate more autonomously because, for example, the leader can tell at a glance what his wing man's fuel state is, his weapons remaining, and even the enemy aircraft he has targeted. This link also allows additional F-22 flights to be added to the net for multi-flight coordinated attack.

7. Litton LN-100F ring laser gyroscopes


Two Litton LN-100F ring laser gyroscopes in the forward fuselage provide the aircraft a self-contained method of knowing where it is. These inertial measurement units, placed nose to nose behind the radar on the aircraft's centerline, are operated off separate data buses to provide independent measurement data. In normal flight, IRS data is fused with Global Positioning System (GPS) data to provide an extremely reliable navigational capability.
The IMUs are the only completely reliable source of data for the aircraft at attitudes above 30 degrees angle of attack (AOA). One of the IRS units feeds data directly into the CIP for gun control steering.

image just for representation.

- CockPit

The new F-22 cockpit redefines the standard of the way fighter aircraft cockpits are supposed to look. It will be designed to let the pilot act as a tactician, as opposed to a simple sensor operator. Pilots of the F-22 will do what humans execute flawlessly, think. The pilot will totally utilize the computer power of the F-22. A few distinct improvements worth mentioning are:

• The first baseline (NVG) Night Vision Goggle compatible cockpit
  
• Traditional analog/ standby dials and gauges, are absent. The F-22 will have the first all modern glass cockpit in a tactical fighter.
  
• Canopy is the made of the largest piece of polycarbonate material in the world. # 1 quality and compatibility with Helmet Mounted systems which enable the pilot to keep his head focused on the target at all times.
  
• Inherent design for growth and development of HMS's.
  

The F-22 features a side-stick controller (like an F-16) in addition to two throttles that are the aircraft's primary flight controls. Located on the right console, the GEC-built stick also serves as a swing-out, adjustable arm rest. The stick is force sensitive and has a throw of only about one-quarter of an inch. The throttles are located on the left console.


An on-board oxygen generation system (OBOGS) that supplies breathable air to the pilot. An integrated breathing regulator/anti-g valve (BRAG) that controls flow and pressure to the mask and pressure garments. A chemical/biological/cold-water immersion (CB/CWI) protection ensemble. An upper body counter pressure garment and a lower body anti-G garment acts a partial pressure suit at high altitudes. An air-cooling garment, which is also going to be used by pilots on the Army's RAH-66 Comanche helicopter provides thermal relief for the pilot. Helmet and helmet-mounted systems including C/B goggles and C/B hood; and the MBU-22/P breathing mask and hose system. The Boeing-led life support development and its suppliers designed the life support system with the F-22's advanced performance capabilities in mind.

The separate components of the life-support system must simultaneously meet pilot protection requirements established by the Air Force in the areas of higher altitude flight, acceleration, heat distress, cold water immersion, chemical and biological environments, fire, noise, and high-speed/high-altitude ejection. Escape-system tests have demonstrated that the life-support system will protect pilots when exposed to wind speeds of up to 600 knots. Current life-support systems are designed to provide protection only up to 450 knots. The head mounted portions of the life-support system are approximately 30 percent lighter than existing systems, which improves mobility and endurance time for pilots. With its advanced design, the HGU-86/P helmet that will be used by F-22 pilots during EMD reduces the stresses on a pilot's neck by 20 percent during high-speed ejection compared to the current HGU-55/P helmets.

The F-22's canopy is approximately 140 inches long, 45 inches wide, 27 inches tall, and weighs approximately 360 pounds. It is a rotate/translate design, which means that it comes down, slides forward, and locks in place with pins. It is a much more complex piece of equipment than it would appear to be. The F-22 canopy's transparency (made by Sierracin) features the largest piece of monolithic polycarbonate material being formed today. It has no canopy bow and offers the pilot superior optics (Zone 1 quality) throughout (not just in the area near the HUD) and it offers the requisite stealth features. The canopy is resistant to chemical/biological and environmental agents, and has been successfully tested to withstand the impact of a four-pound bird at 350 knots. It also protects the pilot from lightning strikes. The 3/4" polycarbonate transparency is actually made of two 3/8" thick sheets that are heated and fusion bonded (the sheets actually meld to become a single-piece article) and then drape forged.

- Stealth

The F 22 is the first air superiority aircraft which is designed on the concept of stealth. Grammatically stealth means hiding in surrounding in a way that your enemy won't be able to see you clearly. At longer ranges A Fighter aircraft sees another Fighter aircraft by means of a Radar. The USAF therefore emphasised to build an aircraft that absorbs the waves of enemy's radar and deflects the remaining waves in a direction other than back to radar. The USAF's previous experiences with U 2 spy plane , F 117 night hawk having displayed reliability during spy missions and precision strikes missions. The USAF operates B 2 Spirit which is extremely stealthy and has been uninterceptable till now.

The Joint of Vertical Stabiliser and Horizontal stabiliser with aft body of F 22 has been thoughroughly optimised to reduce radar reflection.

The F-22 was designed to be highly difficult to detect and track by radar. Measures to reduce radar cross-section include airframe shaping such as alignment of edges, fixed geometry serpentine inlets that prevent line-of-sight of the engine faces from any exterior view, use of radar absorbent material (RAM), and attention to detail such as hinges and pilot helmets that could provide a radar return. The F-22 was also designed to have decreased radio emissions, infrared signature and acoustic signature as well as reduced visibility to the naked eye. The aircraft’s flat thrust vectoring nozzle reduces infrared emissions to mitigate the threat of infrared homing (“heat seeking”) surface-to-air or air-to-air missiles. Additional measures to reducetheinfrared signature include special paint and active cooling of leading edges to manage the heat buildup from supersonic flight.

The F 22 Raptor's frontal aspect radar cross section is assumed to be 0.0001 m² and the overall aspect radar cross section is assumed to be 0.00016 m². This makess F 22 look of the size of a honey bee. Actually even honey bees have greater radar cross section than F 22 raptor. The current fourth generation Su 27 derivatives of Russia and China and their onboard PESA radars are surely incapable of seeing a honey bee mid air. In a battle they would be completely surprised by seeing a missile launch warning and missile approach warinig very near to them.

Various access panels , doors of internal weapon bays, doors of landimg gear compartments have been shaped with sawtooth edges to reduce radar reflection.

Compared to previous stealth designs like the F-117, the F-22 is less reliant on RAM, which are maintenance intensive and susceptible to adverse weather conditions. Unlike the B-2, which requires climate-controlled hangars, the F-22 can undergo repairs on the flight line or in a normal hangar. The F-22 features a Signature Assessment System which delivers warnings when the radar signature is degraded and necessitates repair. The F-22’s exact radar cross-section (RCS) is classified; however, in 2009 Lockheed Martin released information indicating it has an RCS (from certain angles) of −40 dBsm –equivalent to the radar reflection of a “steel marble”. Effectively maintaining the stealth features can decrease the F-22’s mission capable rate to 62–70%.

-Engine

For a fifth generation fighter it was necessary to have superiority kinematic performance and superior thrust of engine. The F 22 can achieve speeds of Mach 1.8 without firing it's afterburners and can achieve even more than Mach 2 with afterburners. This is because of the super duper engine of F 22.


Each F-22 is powered by two of these 35,000-pound-thrust-class engines. By comparison, the engines powering the Air Force’s current F-15 and F-16 fighters have thrust ratings ranging from 23,000 to 29,000 pounds. The F119 can push the F-22 to supersonic speeds above Mach 1.4 even without the use of afterburner, which gives the fighter a greater operating range and allows for stealthier flight operation. The product of more than 40 years' research into high-speed propulsion systems, the F119 is proof that high-technology doesn't have to be complicated. The F119 engine develops more than twice the thrust of current engines under supersonic conditions, and more thrust without afterburner than conventional engines with afterburner.

Features


Integrally bladed rotors: In most stages, disks and blades are made from a single piece of metal for better performance and less air leakage.


Long chord, shroud less fan blades: Wider, stronger fan blades eliminate the need for the shroud, a ring of metal around most jet engine fans. Both the wider blades and shroud less design contribute to engine efficiency.


Low-aspect, high-stage-load compressor blades: Once again, wider blades offer greater strength and efficiency.


Alloy C high-strength burn-resistant titanium compressor stators: Pratt & Whitney's innovative titanium alloy increases stator durability, allowing the engine to run hotter and faster for greater thrust and efficiency.


Alloy C in augmentor and nozzle: The same heat-resistant titanium alloy protects aft components, permitting greater thrust and durability.


Floatwall combustor: Thermally isolated panels of oxidation-resistant high cobalt material make the combustion chamber more durable, which helps reduce scheduled maintenance.


Fourth-generation full-authority digital electronic engine control (FADEC): Dual-redundant digital engine controls - two units per engine, two computers per unit - ensure unmatched reliability in engine control systems. The same experience that introduced full-authority digital control to fighter engines works with the aircraft system to make engine and aircraft function as a single flight unit.


No visible smoke: Reduces the possibility of an enemy visually detecting the F-22.


Improved Supportability: All components, harnesses, and plumbing are located on the bottom of the engine for easy access, all line replaceable units (LRUs) are located one deep (units are not located on top of one another), and each LRU can be removed with just one of the six standard tools required for engine maintenance.

to know more about propulsion systems in detail click on the link below.

Description of Propulsion

F-22 Engine Nozzle


The F119 engine nozzle for the F-22 is the world's first full production vectoring nozzle, fully integrated into the aircraft/engine combination as original equipment.


The two-dimensional nozzle vectors thrust 20 degrees up and down for improved aircraft agility. This vectoring increases the roll rate of the aircraft by 50 percent and has features that contribute to the aircraft stealth requirements.


Heat-resistant components give the nozzles the durability needed to vector thrust, even in afterburner conditions.
With precision digital controls, the nozzles work like another aircraft flight control surface. Thrust vectoring is an integrated part of the F-22's flight control system, which allows for seamless integration of all components working in response to pilot commands.
The nozzle is manufactured at Pratt & Whitney's West Palm Beach facility, home to the company's military engine design and prototype construction.

- Upgrades

The upgrade programs of F 22 called as increments are executed in a planned and periodic manner. Although by 2012, the update schedule had slipped seven years due to instability in requirements and funding. In 2012 the F-22 was upgraded with a backup oxygen system, software upgrades and oxygen sensors to address the frequent oxygen deprivation issues and normalize operations. In 2013, the faulty flight vest valves were replaced and altitude restrictions lifted; distance restrictions will be lifted once a backup oxygen system is installed.


Other upgrades being developed include infra-red search and track functionality for the AN/AAR-56 Missile Launch Detector (MLD) and integration of a helmet-mounted cuing system (HMCS) to enable off-boresight missile launches by 2020. The upgrades / increments are as follows.

Increment 2

The first F-22 upgrade program, was implemented in 2005 and enabled the aircraft to employ Joint Direct Attack Munitions (JDAM).


Increment 3.1

It provided improved ground-attack capability through synthetic aperture radar mapping and radio emitter direction finding, electronic attack and the GBU-39 Small Diameter Bomb (SDB); testing began in 2009 and the first upgraded aircraft was delivered in 2012.


Increment 3.2

It is a two-part upgrade process

Increament 3.2A focuses on electronic warfare, communications and identification, while 3.2B will allow the F-22 to fully exploit the AIM-9X and AIM-120D missiles.


Increment 3.2B

This upgrade planned for 2018 will include a new stores management system to show the correct symbols for the AIM-9X Sidewinder and AIM-120D AMRAAM and improved control of them.

​
Increment 3.3


They may include the adoption of an open avionics platform and air traffic control updates.

Upgrades in 2015 will allowed the F-22 to employ the AIM-9X and have full Link 16 reception and transmission capability, and an upgrade scheduled in 2018 will integrate the AIM-120D into the weapons suite. The F-22 fleet is planned to have 36 Block 20 training and 149 Block 30/35 combat aircraft by 2016.

The upgrades may also include a stealth optimised external wing station carried ordnance pod

- Challenges from the New Russian and Chinese Designs

The Advanced Tactical Fighter program proposers I think may not have thought that the USAF would still be using their fourth generation F 15 and F 16 even in the second decade of 21st century. Where America's prime enemies Russian Federation and People's Republic of China has grown tougher and challenging the superiority which the ATF would acchive. The Russian designed Sukhoi PAK-FA whose production version would be named Sukhoi Su 50 and mass deployed by 2020 would posses a greater challenge. Although not as stealth as F 22 but by having substantial stealth to look almost the size of a tennis ball forcing the F 22 to come closer in a WVR fight. The design trend of Sukhoi Design Bureau of making Fighters of high kinematic performance and tapping F 22's inability to properly employ 2D thrust vectoring while stall has made the Sukhoi PAK-FA a formidable design level challenge in combat.

Read what a Eurofighter Pilot wants to say after having a combat exercise with F 22 Raptor. Click on the button below.

HERE.

Out of the produced F 22 36 are for Training and 149 are for combat deployment. With service availability rate of nearly 60 to 63%, 93 of them could flown to missions at any time anywhere in the world at short notice. On the other hand RuAF would never be having more than 3 squadrons of Sukhoi Su 50 because of the crippled Russian economic condition. The service availability rate is also expected to be around 65%. Hence at any given time only 39 Su 50s would be available for combat deployment. This much number isn't enough either to deter F 22 or prevent it's fleet's from performing any mission even close to Russian borders. Despite having superior capability Sukhoi PAK-FA won't be strategically challenging for F 22 Raptor unless deployed in heavy numbers.

to see awesome Sukhoi Pak-Fa in detail , click

Sukhoi PAK-FA

The PLAAF poses a different challenge for USAF and F 22 raptor at strategic levels. The Chengdu J 20 made operational in 2016/2017 was managed according to China's Anti Access/ Area Denial strategy. The J 20 would be a mass produced fighter along with Shenyang J 31 whose additive manufacturing technique significantly reduces maintenance and manufacturing time. There aren't any numbers available for statistical guessing but with no doubt a large number of J 20s and J 31s would be deployed in South China Sea. After analysing the research papers published in Chinese scientific journals the Stealth capabilities of J 20 and J 31 was assumed to be stealthy enough to force F 22 into a WVR fight.

To see Chinese Shenyang J 31 in detail click

Shenyang J 31

Being capable of deployment in large numbers any fight between a fleet of F 22 and a fleet of J 20. It could be analysed from similar from findings of a similar study made by Rand corporation. That F 22 would run out of missiles. More J 20s would be available for combat than the number of missiles being carried by F 22. It would at the end be just a simple thing for J 20 to penetrate deep into US air defences and do a non retrievable considerable damage. The Chinese know that they don't need an aircraft to match the capabilities of F 22. They just need numbers to deny access to the South China sea. While pitching aircraft like Shenyang J 31 for exports to cut customers of F 35.

F 35 lightning ll

( click here to see details of F 35 )

- Variants

Their are four known possible variants of this aircraft.

1. YF 22

A technology demonstrator meant for ATF competition. 2 were bulid.

2. F 22 Raptor


The main production version.

3. F 22B

It was planned two seat variant , but was cancelled in 1996 to save development costs.

4. FB 22

A fighter bomber variant based on F 22. It is also called strike raptor. The FB-22 was a proposed medium-range bomber for the USAF. The FB-22 was projected to carry up to 30 Small Diameter Bombs to about twice the range of the F-22A, while maintaining the F-22’s stealth and supersonic speed. However, the FB-22 in its planned form appears to have been canceled with the 2006 Quadrennial Defense Review and subsequent developments, in lieu of a larger subsonic bomber with a much greater range possibly the B 21

5. X 44 Manta

A tailess design based on F 22 for study purpose. The X-44 MANTA, or multi-axis, no-tail aircraft, was a planned experimental aircraft based on the F-22 with enhanced thrust vectoring controls and no aerodynamic surface backup. The aircraft was to be solely controlled by thrust vectoring, without featuring any rudders, ailerons, or elevators. Funding for this program was halted in 2000.

6. Naval Variant of F 22

A carrier-borne variant of the F-22 with variable-sweep wings for the U.S. Navy's Navy Advanced Tactical Fighter (NATF) program to replace the F-14 Tomcat. Program was canceled in 1993. Actually design work was even started and it was a variable wing version of Raptor which was to be designated as F 24.

- Armament

1. M61A2 Vulcan 20 mm cannon

The M61 Vulcan is a hydraulically or pneumatically driven, six-barrel, air-cooled, electrically fired Gatling-style rotary cannon which fires 20 mm rounds at an extremely high rate (typically 6,000 rounds per minute). The M61 and its derivatives have been the principal cannon armament of United States military fixed-wing aircraft for fifty years.

The door opening of the gun

Each of the cannon's six barrels fires once in turn during each revolution of the barrel cluster. The multiple barrels provide both a very high rate of fire—around 100 rounds per second—and contribute to prolonged weapon life by minimizing barrel erosion and heat generation. Mean time between jams or failures is in excess of 10,000 rounds, making it an extremely reliable weapon. The success of the Vulcan Project and its subsequent progeny, the very-high-speed Gatling gun, has led to guns of the same configuration being referred to as "Vulcan cannon", which can sometimes confuse nomenclature on the subject.

2. AIM 9x

The AIM-9 Sidewinder is a short-range air-to-air missile developed by the United States Navy in the 1950s. Entering service in 1956, variants and upgrades remain in active service with many air forces after six decades. The United States Air Force purchased the Sidewinder after the missile was developed by the United States Navy at China Lake, California. It is one of the most widely used missiles in the world: The AIM-9 is equipping most western-aligned air forces, as well as indirectly many nations which received the Soviet K-13 missile, a reverse-engineered copy of the AIM-9.

AIM 9X Missile in the side weapon bays

​The guidance and control unit (GCU) contains most of the electronics and mechanics that enable the missile to function. At the very front is the IR seeker head utilizing the rotating reticle, mirror, and five CdS cells or "pan and scan" staring array (AIM-9X), electric motor, and armature, all protruding into a glass dome. Directly behind this are the electronics that gather data, interpret signals, and generate the control signals that steer the missile. An umbilical on the side of the GCU attaches to the launcher, which detaches from the missile at launch. To cool the seeker head, a 5,000 psi (35 MPa) argon bottle (TMU-72/B or A/B) is carried internally in Air Force AIM-9L/M variants, while the Navy uses a rail-mounted nitrogen bottle.


The AIM-9X model contains a Stirling cryo-engine to cool the seeker elements. Two electric servos power the canards to steer the missile (except AIM-9X). At the back of the GCU is a gas grain generator or thermal battery (AIM-9X) to provide electrical power. The AIM-9X features high off-boresight capability; together with JHMCS (Joint Helmet-Mounted Cueing System), this missile is capable of locking on to a target that is in its field of regard said to be up to 90 degrees off boresight. The AIM-9X has several unique design features including built-in test to aid in maintenance and reliability, an electronic safe and arm device, an additional digital umbilical similar to the AMRAAM and jet vane control.

3. AIM 120 AMARAAM

​The AIM-120 Advanced Medium-Range Air-to-Air Missile, or AMRAAM (pronounced "am-ram"), is a modern beyond-visual-range air-to-air missile (BVRAAM) capable of all-weather day-and-night operations. Designed with 7-inch diameter instead of 8-inch diameter form-and-fit factors, and employing active transmit-receive radar guidance instead of semi-active receive-only radar guidance, it is a fire-and-forget upgrade to the previous generation Sparrow missiles. When an AMRAAM missile is being launched, NATO pilots use the brevity code Fox Three.

AMRAAM has an all-weather, beyond-visual-range (BVR) capability. It improves the aerial combat capabilities of US and allied aircraft to meet the threat of enemy air-to-air weapons as they existed in 1991. AMRAAM serves as a follow-on to the AIM-7 Sparrow missile series. The new missile is faster, smaller, and lighter, and has improved capabilities against low-altitude targets. It also incorporates a datalink to guide the missile to a point where its active radar turns on and makes terminal intercept of the target. An inertial reference unit and micro-computer system makes the missile less dependent upon the fire-control system of the aircraft.

​Once the missile closes in on the target, its active radar guides it to intercept. This feature, known as "fire-and-forget", frees the aircrew from the need to further provide guidance, enabling the aircrew to aim and fire several missiles simultaneously at multiple targets and perform evasive maneuvers while the missiles guide themselves to the targets. The missile also features the ability to "Home on Jamming," giving it the ability to switch over from active radar homing to passive homing – homing on jamming signals from the target aircraft. Software on board the missile allows it to detect if it is being jammed, and guide on its target using the proper guidance system.

4. GBU 39 SMALL DIAMETER BOMB


Since stealth aircraft have a restricted size of weapon bays. It needs a bomb that has smaller cross section. Without compromising lethality. The solution is Small Diameter Bomb.

The GBU-39 Small Diameter Bomb (SDB) is a 250 lb (110 kg) precision-guided glide bomb that is intended to provide aircraft with the ability to carry a higher number of more accurate bombs. Most US Air Force aircraft will be able to carry (using the BRU-61/A rack) a pack of four SDBs in place of a single 2,000 lb (907 kg) bomb. The Small Diameter Bomb II (SDB-II) / GBU-53/B, adds a tri-mode seeker (radar, infrared homing, and semiactive laser guidance) to the INS and GPS guidance of the original SDB. The original SDB is equipped with a GPS-aided inertial navigation system to attack fixed/stationary targets such as fuel depots, bunkers, etc. The second variant (Raytheon's GBU-53 SDB II) will include a thermal seeker and radar with automatic target recognition features for striking mobile targets such as tanks, vehicles, and mobile command posts.

​The small size of the bomb allows a single strike aircraft to carry more of the munitions than is possible using currently available bomb units. The SDB carries approximately 38 lb (17 kg) of AFX-757 high explosive. It also has integrated "DiamondBack" type wings which deploy after release, increasing the glide time and therefore the maximum range. Its size and accuracy allow for an effective munition with less collateral damage. Warhead penetration is 3 feet (0.91 m) of steel reinforced concrete and the fuze has electronic safe and fire (ESAF) cockpit selectable functions, including air burst and delayed options.

5. GBU 32 JOINT DIRECT ATTACK MUNITION


The JDAM is an improvement over Laser Guided Bombs which are susceptible to failed targeting due to bad weather. It is a guidance kit that converts unguided bombs, or "dumb bombs", into all-weather "smart" munitions. JDAM-equipped bombs are guided by an integrated inertial guidance system coupled to a Global Positioning System (GPS) receiver, giving them a published range of up to 28 km. JDAM-equipped bombs range from 227 kg to 907 kg.


The term GBU Guided Bomb Unit is attached when JDAM kit is attached to a bomb. Their ate many GBUs , but the particular one used in F 22 is GBU 32. Its length is 303.5 cm. Weight is 460 kgs and wingspan of 49.8 cm.

JDAM is a guided air-to-surface weapon that uses either the 2,000-pound BLU-109/MK 84, the 1,000-pound BLU-110/MK 83 or the 500-pound BLU-111/MK 82 warhead as the payload. JDAM enables employment of accurate air-to-surface weapons against high priority fixed and relocatable targets from fighter and bomber aircraft. Guidance is facilitated through a tail control system and a GPS-aided INS. The navigation system is initialized by transfer alignment from the aircraft that provides position and velocity vectors from the aircraft systems.


Once released from the aircraft, the JDAM autonomously navigates to the designated target coordinates. Target coordinates can be loaded into the aircraft before takeoff, manually altered by the aircrew before weapon release, or automatically entered through target designation with onboard aircraft sensors. In its most accurate mode, the JDAM system will provide a weapon circular error probable of 5 meters or less during free flight when GPS data is available. If GPS data is denied, the JDAM will achieve a 30-meter CEP or less for free flight times up to 100 seconds with a GPS quality handoff from the aircraft. JDAM can be launched from very low to very high altitudes in a dive, toss or loft and in straight and level flight with an on-axis or off-axis delivery. JDAM enables multiple weapons to be directed against single or multiple targets on a single pass.

- General Characteristics

• Crew: 1

• Length: 62 ft 1 in (18.92 m)

• Wingspan: 44 ft 6 in (13.56 m)

• Height: 16 ft 8 in (5.08 m)

• Wing area: 840 ft² (78.04 m²)

• Airfoil: NACA 64A?05.92 root, NACA 64A?04.29 tip

• Emptyweight: 43,340 lb (19,700 kg)

• Loaded weight: 64,840 lb (29,410 kg)

• Max. takeoff weight: 83,500 lb (38,000 kg)

• Powerplant: 2 × Pratt & Whitney F119-PW-100 pitch thrust vectoring turbofans

• Drythrust: 26,000 lb (116 kN) each

• Thrust with afterburner: 35,000+ lb (156+ kN) each

• Fuel capacity: 18,000 lb (8,200 kg) internally, or 26,000 lb (12,000 kg) with two external fuel tanks Performance

• At altitude: Mach 2.25 (1,500 mph, 2,410 km/h) [estimated]

• Supercruise: Mach 1.82 (1,220 mph, 1,960 km/h)

• Range: >1,600 nmi (1,840 mi, 2,960 km) with 2 external fuel tanks.

• Combat radius: 460 nmi (with 100 nmi in supercruise clean)

Hope you have recieved something , which is not usually available. Feel free to ask any query if you have. Have a look around the website.

Images and Info Sources

Largely taken from F22fighter.com F16.net, Lockheed Martin, Thai Military and Asian Region Blog, Wikipedia, The Aviationist , The Busissiness Insider

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