Key Deficiencies of Rafale Design
To reach the potential capabilities of Typhoon, Rafale requires a couple of minor alterations:
1) More powerful engines (say some extra 20% thrust)
2) A new radar (an active e-scan to replace the poor performing passive e-scan)
Both items have been requested by the UAE, as they have realised pretty quickly the key shortcomings of the French design.
An AESA radar should be available from 2012, but a new engine is still far away, if it will ever come.
Typhoon will eventually re-establish its superiority in radar performance with the new AESA radar due around 2015. This will be maintained going forward, as Typhoon´s antenna diameter is bigger than Rafale´s and thus can house more receive/transmit modules. Size matters!
For a prospective buyer considering the two jets one can summarise that Rafale will never be able to reach Typhoon´s air-to-air capabilities (aerodynamics and sensors in particular), whereas Typhoon will easily match Rafale´s air-to-surface roles. Just a matter of time and customer´s requests.
Another major difference with Typhoon (and most modern fighters) is the lack of towed decoys, which have proved very effective in enhancing the platform survivability.
Some of the reasons the original five-nation European Fighter went two separate ways are evident from what said above:
1) French strong bias towards air-to-ground vs Eurofighter optimisation on air superiority
2) French insistence on an electronic scan radar whose technology was flawed (and lack of appreciation of antenna size)
3) French insistence on their national engine (underpowered)
Last but not least the governance issue (French leadership of the project).