Aspiring to Fifth Generation Fighters

A Royal Australian Air Force F-35A Lightning II flies in formation with RAAF F/A-18 Hornets. (Commonwealth of Australia)

David Oliver – The latest generation of fighters is not only coming to Asia-Pacific, but is being also developed within the region.

In April 1991 the Lockheed Martin F-22 was declared the winner of the United States Air Force (USAF) Advanced Tactical Fighter (ATF) programme for a stealthy multirole combat aircraft. Incorporating low observables technology and supersonic cruise without afterburning, the F-22 Raptor which gained full operational capability (FOC) in December 2007, was the world’s first fifth-generation fighter aircraft.

In October 2001 Lockheed Martin’s X-35 beat Boeing’s X-32 and was selected as the winner of the USAF/US Navy Joint Strike Fighter (JSF) competition and five years later the F-35A Lightning II completed its first flight. Claimed by Lockheed Martin to be the only fifth-generation supersonic multirole fighter in production, it combines advanced stealth capabilities with fully fused sensor information, network-enabled operations and advanced logistics and sustainment. It is also the fighter of choice for many Asia-Pacific air forces.

The Royal Australian Air Force (RAAF) is taking delivery of 72 F-35A Lightning IIs to equip three operational squadrons and an operational conversion unit (OCU), and it has a requirement for up to 100 aircraft.

Japan has ordered an initial 45 F-35As for the Japan Air Self-Defence Force (JASDF) for its F-X programme to replace the F-4EJ Phantom fleet. In 2018 an additional 105 Lightning IIs were ordered, 42 of which will be the short take-off and landing (STOVL) F-35B variant although the planned licence assembly by Mitsubishi has been dropped.

The first Mitsubishi assembled F-35A was unveiled in Nagoya Japan on 5 June 2017. (Lockheed Martin)

As part of South Korea’s increased defence budget, 40 F-35As are being acquired for the Republic of Korea Air Force (ROKAF), also to replace its Phantom fleet. Singapore is already a Security Cooperative Partner (SCP) in the F-35 programme which is a serious sign of interest in the aircraft. The Republic of Singapore Air Force (RSAF) has expressed interest in acquiring the F-35A to replace its fleet of F-16C/Ds but following extensive evaluation of the aircraft, no decision has been made to date for its purchase. Singapore has been building landing helicopter deck (LHD) variant of the navy’s Endurance-class LPDs that would be capable of operating the STOVL F-35B.

However, for those countries that do not have the budgets to acquire the F-35, Eurofighter, Dassault and Saab are offering four-plus generation aircraft with fifth-generation capabilities, namely the Typhoon, and Rafale and Gripen. To date Eurofighter has failed to penetrate the Asia-Pacific market although the Typhoon has been offered to Malaysia and Indonesia while Dassault is on the verge of completing a deal to supply 36 Rafales to replaced the Indian Air Force (IAF) fleet of Mirage 2000s and the type in is the running for Indian Navy’s requirement for 57 advanced fighter aircraft. The Gripen N is being offered for the Navy contract and the Gripen E for the Indian Air Force’s (IAF) requirement for 110 aircraft to replace its MiG-21/23/27 and SEPECAT Jaguar fleets.

Even more protracted is the IAF’s Fifth-Generation Fighter Aircraft (FGFA) programme for the procurement of 144 single-seat aircraft based on the Russian twin-engine Sukhoi T-50. In 2003 India expressed an interest in joining the T-50 development team and in December 2010, India and Russia signed an agreement covering the development of an advanced version for the IAF to fly in prototype form by 2015.

Until mid-2018 India planned to develop its Fifth-Generation Fighter Aircraft (FGFA) from Russia’s Su-57. (UAC)

Although nine T-50 prototypes, now designated Su-57, have flown to date, development has been slow. The first successful test flight with a Su-57 using the new Izdeliye-30 turbofan engine took place on 5 December, 2017. Thrust-vectoring will be standard and allow for the required agility with the new engines the Su-57 is expected to offer kinematic performance comparable to the F-22 Raptor, cruising without afterburner at speeds exceeding Mach 1.5 with a maximum speed of Mach 2.0 with an operational service ceiling of 65,000 feet (19,800 metres). However, the engine will not be in production until 2025 delaying the aircraft’s entry into Russian service to 2027 at the earliest.

In July 2018, India told Russia it was unwilling to go ahead with the joint development of a FGFA primarily due to technical, cost and delivery timeframe problems although negotiations between the two countries have not yet been shelved as India was ready to look again at co-development of the jet if an appropriate cost-sharing formula between the two countries could be agreed.

At the same time India is developing another Indian fifth-generation multirole fighter aircraft programme, the Advanced Medium Combat Aircraft (AMCA). The stealthy single-seat twin-engine double-delta aircraft is being developed by an aerospace industry consortium comprising the Indian Ministry of Defence’s Aeronautical Development Agency (ADA) which is responsible for the design with manufacturing carried out by Hindustan Aeronautics Limited (HAL).

It is intended to be powered by domestically manufactured upgraded Kaveri afterburning turbofans currently undergoing development by the Gas Turbine Research Establishment. The design of the proposed upgraded Kaveri that will be a 90kN thrust class engine, is being assisted by the French manufacturer Safran. The feasibility study on AMCA and the preliminary design stage have been completed and the project awaits approval to begin development with a first flight scheduled for 2032.

India is not the only country in the region to develop an indigenous fifth-generation fighter aircraft. Due to the United States refusal to export the F-22, Japan is launching a new Future Fighter programme to replace the JASDF Mitsubishi F-2 fleet in the 2030s. In April 2016, the Mitsubishi Advanced Technology Demonstrator – X (ATD-X) experimental aircraft for testing advanced stealth fighter aircraft technologies developed by the Japanese Ministry of Defense Technical Research and Development Institute (TRDI) was first flown. The information gained from the ATD-X’s test flights will be fed into the Future Fighter project, tentatively designed the F-3, which will be a heavy single seat aircraft very similar in design to the F-22, and powered by two 33,000 lb thrust Ishikawajima-Harima Heavy Industries (IHI) XF9-1 afterburning turbofan engines.

The Mitsubishi ATD-X experimental aircraft used for testing stealth fighter aircraft technologies for Japan’s Future Fighter Aircraft pro-gramme. (Mitsubishi)

Japan is also been looking for international partners to collaborate with Mitsubishi Heavy Industries and various Japanese sub-contractors on the Future Fighter programme. In July 2018 Japanese Defense Minister Itsunori Onodera confirmed that the Japan and the UK had “an exchange of opinions” on the Tempest Future Fighter Aircraft project noting that the UK is also “looking for international joint development partners.” Northrop Grumman, which lost the USAF ATF competition with is futuristic YF-23, while Lockheed Martin is reportedly offering a development of its ATF winner, the F-22.

South Korea is also developing a fifth-generation combat aircraft, the KF-X. Announced in 2001, the concept was outlined by the Defence Acquisition Programme Administration (DAPA) but the project was put on hold in 2010 due to the country’s financial situation. However, in April 2011 DAPA confirmed the signing of an agreement between South Korea and Indonesia to jointly develop the Korean KF-X next-generation fighter aircraft. Indonesia is undertaking 20 percent of development costs and plans to obtain as many as 80 IF-Xs under the programme to replace its F-16s and Su-27s while the ROKAF plans to obtain 120 aircraft to replace its F-16s.

Korea Aerospace Industries (KAI) is developing the KF-X to replace the ROKAF F-4 fleet with Indonesia as a partner. (KAI)

The KF-X/IF-X will be a medium-class, twin-engine, multirole stealth fighter with AESA radar, internal weapon bays, supercruise and sensor fusion. It will be produced in both single and twin-seat versions and be powered by two 22,000lb thrust General Electric F414-400 turbofan engines which was selected ahead of the EuroJet EJ200 in April 2016. Compared to KF-16, the KF-X will have a 50 percent greater combat radius, 34 percent longer airframe lifespan, better avionics electronic warfare, IRST, and datalink capabilities.

The KF-X/IF-X design is similar in configuration to the F-22, with chined nose and outward-canted fins. Alignment of the leading edges of the wings, root extensions and tailplanes is 40 degrees aft sweep, while trailing edges are aligned 10 degrees forward.

Part of Lockheed Martin’s contract for ROCAF Lightning IIs was an understanding that it would provide technologies associated with the F-35A for the KF-X programme. However, in September 2015, DAPA announced that the US has refused to grant export licenses for four key technologies including AESA radar, Infra-red Search and Tracking (IRST) System, Electro-Optical Tracking System and next generation radio frequency jammers for indigenous production delaying the development until at least 2025.

In January 2016 the Engineering and Manufacturing Development (EMD) phase for six KF-X prototypes was launched to be completed during the first half of 2026 at a cost of $6.9 billion. First KF-X prototype is planned to achieve its maiden flight in mid 2022. The South Korean manufacturer Hanwha Techwin will build the engines locally under license. In May 2017 it was disclosed that DAPA has signed a technology support contract with IAI’s ELTA Systems for the airborne testing AESA radar for the KF-X and in December 2017 Saab signed a contract for an AESA radar development programme in South Korea. Saab will work in co-operation with the South Korea Agency for Defense Development (ADD) and its contractual partner LIG Nex1, a South Korean aerospace manufacturer and defense company.

Meanwhile, PT Dirgantera Indonesia (PTDI) president director Budi Santoso declared that the fifth prototype would be produced in 2022 at the PTDI facility in Bandung, Indonesia. “The IF-X will have a greater range as required by the Indonesian Air Force. For air refuelling, the IF-X will use a probe system while the KF-X will use a boom system. The third difference will be the data link. South Korea will use the US-made Link 16 and probably while we will also develop our own.” According to Santoso, Indonesia plans to have its own data link to allow communications with the Indonesian Air Force’s Russian Su-27/30 fighter aircraft. However, Indonesia is currently negotiating to reduce its 20 percent share of the development costs.

China’s Chengdu J-20A air superiority fighter has entered service with a People’s Liberation Army Air Force flight test and training unit.

One of the drivers behind the Asia-Pacific nations acquiring or developing fifth-generation fighter aircraft in China’s perceived power projection ambitions backed by recent increased defence spending. However, although the stealthy twin-engine Chengdu J-20A air superiority fighter was officially reported to have entered People’s Liberation Army Air Force (PLAAF) service in February 2018, fewer than 20 have been assigned to the 172 Brigade Flight Test and Training Base. The type is not expected to be issued to operational units until production aircraft are fitted with the thrust-vectoring version of the indigenous WS-15, a 30,000lb (134kN) thrust turbofan engine under development.

In the meantime, development of the smaller Shenyang FC-31 multirole fifth-generation fighter has been revived after being delayed by lack of funding. The prototype, designated as the J-31, made its first flight in October 2012. Aimed initially at the export market, the J-31 suffered from a number of design issues which have now been reported to have been rectified and both the PLAAF and the PLA Navy are interested in the FC-31 as a counter-air and deep strike fighter aircraft. The twin- engine J-31 was powered by Russian Klimov RD-93 turbofan engines, although there are plans to power production FC-31 aircraft with the indigenous Guizhou WS-13E, a 22,450lb (100kN) thrust turbofan with afterburner which is another engine under development.

The next decade will see the Asia-Pacific region deploying more fifth-generation combat aircraft anywhere in the world apart from the United States although not all the development programmes of these advanced tactical fighters will reach fruition.

by David Oliver