*3.1.3 Multirole combat aircraft (multirole, fighter bomber, strike fighter)*

The MRCA roles may include air-to-air combat, bombing operation, aerial photo reconnaissance, etc. The main motivation for developing multirole aircraft is cost reduction in using a common airframe. Multirole means an aircraft with major roles, a primary air-to-air combat role and a secondary role like air-to-surface attack. It may be appreciated that an aircraft optimized for a particular role may not fulfil some other role efficiently; however, they may be gainfully used for secondary roles. For example, air superiority fighters designed for higher manoeuverability over the contemporary aircraft are also capable of ground attack. Similarly an interceptor having high rate of climb and acceleration and equipped with close combat missiles and air guns can also be used to chase enemy aircraft and neutralize them in air. Aircraft roles can be changed by changing on-board armament stores/ role equipment. Some aircraft are retro modified for additional role. The F-14 was envisioned originally for air superiority and fleet interception defence with some variants later receiving secondary ground attack capability.

The Euro fighter Typhoon and Dassault Rafal are classified as multirole fighters. Euro fighter Typhoon was however, originally designed as an air superiority fighter.

### *3.1.4 Electronic warfare (EW) aircraft*

An EW aircraft is a military aircraft equipped with EW system meant to degrade the effectiveness of enemy radar and radio systems by using radar jamming deception methods. EW is a technology to detect, identify the frequency spectrum and locate the source of electromagnetic energy and use of self-protective jammer to deny the opponent access to the EM spectrum. EW can be deployed from land, sea or air. Various types of self-protective jammers like noise/frequency jamming and counter-measure dispensing systems (CMDS) are used. This gives the aircraft stealth capability to deceive the enemy radars. F-35 has very advanced EW capability which enables it to reach well-defended targets and suppress enemy radars that threaten the F-35.

#### *3.1.5 Maritime patrol aircraft*

A maritime patrol aircraft is designed to operate for long duration over coastline/water territory in order to detect, identify enemy ships and submarines and destroy them using air-to-surface weapon, torpedoes and underwater mines. These aircraft are equipped with various sensors including sonar and radars and are also used in maritime search and rescue operations. Jaguar maritime patrol aircraft is one such aircraft that is in use for a long time.

#### **3.2 Fighter aircraft generations**

Aircraft is designed for an economic life of 20 years from the consideration of obsolescence. However, as the cost of procurement of new aircraft is continuously rising, aircraft are operated for longer period, and midlife update is carried out to make the aircraft competitive to contemporary aircraft. This has brought a concept of fighter generation categories created to identify major technology leaps in the historical development of jet fighters. Though there is no sound technological basis, this is more of a creation of aerospace webs and magazines. A general grouping is done based on the operational capabilities, handling qualities and pilot work load as well as the year of design. The aircraft generation is discussed below [6, 7]:

**9**

*Military Aviation Principles*

rockets.

*DOI: http://dx.doi.org/10.5772/intechopen.87087*

a.First-generation fighters (1945–1955)—the first-generation fighters were those built in the beginning of the jet age (World War II). These were fitted with jet but otherwise similar to earlier piston engine aircraft. They were subsonic, did not have radar and had conventional weapons like gun, dumb bombs and

b.Second-generation fighters (1955–1960)—the second-generation fighters were a class superior to the first-generation fighters as regards their speed of operation and combat effectiveness. These were fitted with radar and equipped with guided air to air missiles. This generation also took advantage of the new

c.Third-generation fighters (1960—1970)—the third-generation fighters were designed specifically as multipurpose fighters capable of performing both air defence and ground attack missions. McDonnell Douglas F4H Phantom, British

d.Fourth-generation fighters (1970–1990)—the fourth-generation (4G) fighters are high-manoeuverability multirole fighters with sophisticated avionics and weapon systems and long-range AAM. During this generation, FBW and relaxed static stability FCS concept were introduced. The advance of microcomputers in the 1980s and 1990s permitted rapid upgrades to the avionics over the lifetimes of these fighters, incorporating system upgrades such as AESA, digital avionics busses and infra-red search and track (IRST). 4+ generation fighters (1990–2000) are also sometimes used to indicate more advanced features that might be seen in fifth-generation fighters. F-16, Mirage 2000 and MiG-29 are 4G fighters, while F/A-18 Hornet, Eurofighter Typhoon

and Dassault Rafale can be designated as 4+ generation fighters.

and Indian AMCA is in early stages of development.

**3.3 Fighter aircraft operational profile**

e.Fifth-generation fighters (2000 onwards)—the fifth-generation (5G) designation is used that encompasses the fighter technologies developed during the first part of the twenty-first century. The 5G jet fighters are expected to have 'pilot associates': integrated avionics and computer system capable of networking with other elements that provide the pilot with complete picture of the battlespace and situational awareness. The other features include the use of low-observable 'stealth' and high-performance airframes. Some of 5G fighters are the Lockheed Martin F-22 Raptor with USAF (2005) and the Lockheed Martin F-35 (USAF 2015) and the Chengdu J-20 with the People's Liberation Army Airforce (2017). Sukhoi SU-57 being developed for the Russian Air Force

Combat radius or radius of action (ROA) of military aircraft refers to the maximum distance the aircraft can travel from the operating base with operational load, complete operational mission and return without refueling, allowing for reserve fuel and all other safety requirements. The thumb rule is that ROA is one third the distance an aircraft can fly on full load and total fuel. Operational mission planning is done for offensive roles to maximize the ROA without taking

undue risk of enemy detection and attack. Some considerations are [1, 5]:

a.Low-level flight missions will have smaller ROA due to higher drag and fuel consumption; however, it will have low radar detection probability.

development of electronics in the aircraft systems.

Aerospace Harrier and MiG-23 belong to this class.
