‘4.5 Generation’ Fighters – Multi Role Aircraft in Search of a Role

Europe’s leading manufacturers are competing with each other to sell the latest generation fighters. But in an age of decreasing defence budgets, air forces around the world are being more cautious with their new purchases. 

The Eurofighter Typhoon, Saab JAS-39 Gripen and Dassault Rafale continue to compete furiously for export orders. Shrinking European defence budgets mean companies such as BAE Systems, Saab and Dassault have to rely on export orders to make their fighter jet programmes affordable. In December 2013, Brazil confirmed the latest deal with Swedish Gripen. In January 2013, India named the Rafale as the preferred bidder for a 126 aircraft deal. This was hotly contested by the Typhoon consortium which in 2006 won a similar competition to supply seventy-two aircraft to the Kingdom of Saudi Arabia.

It is noteworthy how long these competitions last. The Brazilian F-X2 competition took four years to decide between the shortlisted Rafale, Gripen and Boeing F/A-18E/F Super Hornet. Whilst this protracted timescale is partly a result of the politics integral to international defence sales, the difficulty in choosing between these aircraft is also caused by the difficulty for any foreign air force in specifying exactly what roles these aircraft are needed to perform. The respective merits of the ‘4.5 Generation’ fighters are well known so multiple competitive fly-offs should not be required.

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Eurofighter TyphoonDassault RafaleSaab GripenBoeing F/A-18E/F

Maximum payload16,500 lb20,900 lb15,800 lb18,000 lb

Thrust/Weight Ratio1.150.9880.970.93

Maximum Altitude65,000 ft50,000 ft50,000 ft50,000+ ft

Estimated Unit Cost$115m$95m$60-70m$55-65m

The Competitors

In simplest terms, if an air force wants a current-generation ‘no-frills’ fighter for sky policing and limited air-to-ground capability then the Gripen is the obvious choice. The Rafale is the most capable strike platform of the three whilst still offering impressive air-to-air capability, although its small radar aperture and underpowered Snecma M88-2 engines are limiting factors. The Typhoon has the edge over both Gripen and Rafale in terms of Beyond Visual Range (BVR) combat, top speed, acceleration, manoeuvrability, service ceiling and climb rate. It is widely considered to be the most capable air superiority fighter of the three and is also a potent strike aircraft with excellent sensors but slightly reduced ordinance-carrying capacity compared to the Rafale.

Due to the, often deliberate, confusion over what is included in a quoted price tag for modern fighter aircraft it is nearly impossible to precisely compare the costs of Gripen, Rafale and Typhoon.  However, rough flyaway unit costs in US$ at 2013 exchange rates are $60-70M for Gripen, $90-100M for Rafale and $110-120M for Typhoon.

‘Omni-Role’ capability and 4.5 Generation Performance

Financial constraints make it hard for any air force to justify procuring a single role, high-end military aircraft. The Pentagon’s 2009 decision to cap F-22 Raptor air-superiority fighter production at 195 aircraft and concentrate on the more versatile F-35 Joint Strike Fighter shows that even the US Air Force cannot afford large numbers of ‘pure’ fighter aircraft. It is no surprise, therefore, that a key requirement in all recent export competitions has been the capability to excel in air-to-air combat whilst also being capable of accurate and powerful strikes against distant and defended targets. However, whilst Saab, Dassault and the Typhoon consortium all claim that their aircraft are superbly capable in both roles; claims that a single aircraft can perform both missions effectively during a single sortie deserve careful scrutiny.

On 23 January 2014 Dassault proudly announced that their Rafale aircraft had completed its first test flight in ‘heavily armed’ configuration, taking off with six air-to-surface missiles, six air-to-air missiles and 6000 litres of extra fuel in external tanks. The company claims that a pair of Rafale aircraft so armed represents the same potential combat capability as six legacy Mirage 2000 jets. However, it seems logical to assume that even an aircraft as advanced as the Rafale will struggle to deliver top level air-to-air combat potential whilst burdened with one and a half times its empty weight in external stores, given the resultant thrust-to-weight and drag penalties.

The distinguishing capabilities of so called ‘4.5 Generation’ fighters such as the Typhoon, Rafale and Gripen include low-observability to radar; the ability to supercruise (fly at supersonic speed without using afterburners); and extreme manoeuvrability at all speeds. The excellent beyond-visual-range (BVR) and within-visual-range air combat capabilities of all three European fighters revolve around supercruising at very high altitude using powerful sensors and long range missiles, as well as being able to sustain high energy levels during extreme manoeuvres in a dogfight. Neither set of capabilities is possible with a heavy load of strike munitions and extra fuel tanks so the ‘omni-role’ mission profile advertised by 4.5 generation fighter manufacturers is misleading unless that mission is undertaken against an enemy force with weak air defence systems and out of date interceptors. In such a case, a legacy fighter such as the F/A-18E/F or Tornado GR.4 would be capable of carrying out the mission whilst being much cheaper to acquire.

An Uncertain Role for 4.5 Generation Fighters

Outside a head-on aerial confrontation between national air forces, which for most operators of such aircraft is a highly remote possibility, there are few missions that a 4.5 generation fighter might be required to perform which could not be undertaken by cheaper, combat-proven legacy fighters. Sky policing and close air support are cases in point. The argument that Typhoon and Rafale are better able to penetrate defended airspace in a strike or reconnaissance role during a limited conflict is weakened by their lack of true stealth technology and their high cost which makes the risk of losing even a few to enemy action a serious disincentive.

Only a fifth generation fighter such as the F-35 is likely be able to penetrate the air defence of a near-peer enemy with a politically acceptable risk level as systems like the Russian S-400 mobile SAM and Su-27/30 fighter range proliferate over the next 10-15 years. South Korea and Japan who face a potential peer opponent in the shape of China have both rejected 4.5 generation offerings in favour of waiting for F-35 at higher cost.

While the performance gains offered by the three European aircraft over their predecessors are highly impressive, it is far from clear exactly what missions are likely to require them. Obviously there is a political need to provide conventional deterrence and maintain a visibly formidable air force for defence and expeditionary purposes but if an air force faces the genuine possibility of a limited conflict with a peer enemy which clearly justifies serious defence expenditure, it is more likely to wait and buy F-35 or Russia’s PAK FA than to choose Typhoon, Rafale or Gripen.  

The views expressed here are the author's own and do not necessarily reflect those of RUSI.


Professor Justin Bronk

Senior Research Fellow, Airpower & Technology

Military Sciences

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