The four partner nations in the Eurofighter Typhoon are trying to firm up their roadmap for continual upgrades of their design, partly to seek export markets and partly to stay up with the current state of air warfare. Europe expects to be flying Typhoons beyond 2040 and knows this will only be possible if they are continually refurbished and upgraded. To simplify logistics, the Europeans want to be operating only two sub-types of Typhoon at any given time. Current plans call for buying 148 Tranche-1 aircraft (these are under contract) followed by 236 improved Tranche-2 fighters. (Budget problems will probably force the number of Tranche-2s below 200.) The Tranche-3 design is to begin production in 2010 and to have considerable improvements. At about that time, the Tranche-1 aircraft will be upgraded to Tranche-3 (or sold off and replaced by new production). The Europeans envision buying 236 new Tranche-3 aircraft, but as a contract for them is years away it is anyone's guess how many will actually be bought. Tranche-3 will include an electronically-scanned radar, allowing it to function as a superiority fighter and cruise missile killer. It will also have precision ground attack capabilities. As time goes by, the Europeans expect to replace the engines on their Typhoons with new designs with thrust-vector technology.--Stephen V Cole