Fifth generation jet fighter
Fifth-generation fighters are characterized by being designed from the start to operate in a network-centric combat environment, and to feature extremely low, all-aspect, multi-spectral signatures employing advanced materials and shaping techniques. They have multifunction Active Electronically Scanned Array radars with high-bandwidth, low-probability of intercept (LPI) data transmission capabilities. Infra-red Search and Track sensors are incorporated for air-to-air combat as well as for air-to-ground weapons delivery. These sensors, along with advanced avionics, glass cockpits, helmet-mounted sights, and improved secure, jamming-resistant LPI data links are highly integrated to provide multi-platform, multi-sensor data fusion for vastly improved situational awareness while easing the pilot's workload. Overall, the integration of all these elements is claimed to provide fifth-generation fighters with a "first-look, first-shot, first-kill capability".
The AESA radars in addition to its high resistance to ECM and LPI features, it enables the fighter to function as a sort of "mini-AWACS," providing high-gain electronic support measures and electronic warfare jamming functions.
Other technologies common to this latest generation of fighters includes integrated electronic warfare system (INEWS) technology, integrated communications, navigation, and identification (CNI) avionics technology, centralized "vehicle health monitoring" systems for ease of maintenance, fiber optics data transmission and stealth technology.
Maneuver performance remains important and is enhanced by thrust-vectoring, which also helps reduce takeoff and landing distances. Supercruise may or may not be featured; it permits flight at supersonic speeds without the use of the afterburner – a device that significantly increases IR signature when used in full military power.
A key attribute of fifth-generation fighters is very-low-observables stealth. Great care has been taken in designing its layout and internal structure to minimize RCS over a broad bandwidth of detection and tracking radar frequencies; furthermore, to maintain its VLO signature during combat operations, primary weapons are carried in internal weapon bays that are only briefly opened to permit weapon launch. Furthermore, stealth technology has advanced to the point where it can be employed without a tradeoff with aerodynamics performance.
Previous generation stealth aircraft, such as the B-2 Spirit and F-117 Nighthawk, lacked LPI radars and LPI radio networks and so were limited to attacking ground targets because engaging other aircraft would have them revealed.
The primary characteristics of this sub-generation are the application of advanced digital avionics and aerospace materials, modest signature reduction (primarily RF "stealth"), and highly integrated systems and weapons. These fighters have been designed to operate in a “network centric” battlefield environment and are principally multirole aircraft. Key weapons technologies introduced include beyond-visual-range (BVR) AAMs; GPS-guided weapons, solid state phase-array radars; helmet-mounted sights; and improved secure, jamming-resistant datalinks. Thrust vectoring to further improve transient maneuvering capabilities have also been adopted by many 4.5th generation fighters, and uprated powerplants have enabled some designs to achieve a degree of “supercruise” ability. Stealth characteristics are focused primarily on frontal-aspect radar cross section (RCS) signature-reduction techniques including radar absorbent materials (RAM), L-O coatings and limited shaping techniques.
Fourth-generation jet fighter
The main features of this generation of aircrafts are capability to perform "fast transients" – quick changes in speed, altitude, and direction – as opposed to rely chiefly on high speeds alone, “relaxed static stability” made possible by introduction of the "fly-by-wire" (FBW) flight control system (FLCS), which in turn was enabled by advances in computers and system integration techniques. Analog avionics, required to enable FBW operations, Full Authority Digital Engine Controls to electronically manage powerplant performance, pulse-Doppler fire-control radars, head-up displays (HUD),”hands on throttle-and-stick” (HOTAS) controls, and multi-function displays (MFD). Infrared search and track (IRST) sensors became widespread for air-to-ground weapons delivery, and appeared for air-to-air combat as well. "All-aspect" IR AAM are standard air superiority weapons, which permitted engagement of enemy aircraft from any angle.
Reference : www.wikipedia.org
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