The Eurofighter Typhoon is in service with seven nations: United Kingdom, Germany, Italy, Spain, Saudi Arabia, Oman and Austria. It has been ordered by Kuwait and Qatar, with orders for all eight customers still pending as of September 2017. The aircraft has, as of 2016, been provided in a basic air-defense form and has been upgraded to newer production standards which include internal IRST, air-to-ground precision strike capability (with Royal Air Force Typhoons participating in air strikes destroying tanks in Libya in 2011 as their combat debut), and HMSS (helmet-mounted symbology system) helmets. Most of the major systems including the CAPTOR radar and the Defence Aids Sub-System (DASS) are expected to be improved and updated over time, with the radar being updated to an AESA, being the CAPTOR-E/CAESAR, of which the Kuwait Air Force will be the inaugural operator, with first deliveries of their 28 new-built aircraft to commence in 2019. Development aircraft Seven development aircraft (DA) were built with varying equipment fits and flight test roles. DA1 DA1's main role was handling characteristics and engine performance. DA1 was assembled in 1992 and first flew on 27 March 1994 with Luftwaffe serial 98+29. The military evaluation phase commenced in 1996. In 1997 after 123 flights, DA1's RB199 engines were replaced by EJ200s, it also was refitted with the Martin-Baker Mk.16A ejector seat and a full avionics fit. Following these modifications it rejoined the flight test programme in 1999. Following the loss of DA6, DA1 was transferred to Spain to undertake the remaining development work including IRIS-T trials. The aircraft was retired on 21 December 2005, eleven years, eight months, and 24 days after its first flight. It is on display at the Flugwerft Schleißheim (external site of the Deutsches Museum) near Munich, Germany. DA2 DA2 undertook envelope expansion, flight control assessment and load trials. The aircraft first flew on 6April 1994 as ZH588. The flight control assessment included development of the Eurofighter's "carefree handling". On 23 December 1997 DA2 became the first Eurofighter to achieve Mach2 and in January 1998 undertook refuelling trials with a RAF VC10. Like DA1, DA2 was upgraded in 1998 with new engines, ejector seat and avionics and rejoined the test programme in August. In 2000 the aircraft was covered with 490 pressure transducers; due to the fact that they were covered by black pads and had associated wiring the aircraft was painted in a gloss