The air forces of EU member states operate a wide range of military systems and hardware. This is primarily due to the independent requirements of each member state and also the national defence industries of some member states. However such programmes like the Eurofighter Typhoon and Eurocopter Tiger have seen many European nations design, build and operate a single weapons platform. 60% of overall combat fleet was developed and manufactured by member states, 32% are US-origin, but some of these were assembled in Europe, while remaining 8% are soviet-made aircraft. As of 2014, it is estimated that the European Union had around 2,000 serviceable combat aircraft (fighter aircraft and ground-attack aircraft).