Eurofighter Typhoon ISPA4

ISPA4 is one of the five Instrumented Series Production Aircraft (ISPA) of the Eurofighter programme: airframes diverted from the production line, as the IPAs were, but carrying less telemetry instrumentation than those. On the ISPAs the internal gun bay is used to house the test avionics, which are connected to the aircraft's fibre-optic bus, and the modification is reversible, so that the aircraft can be returned to series standard. Unlike the development aircraft and the IPAs, the ISPAs are legally the property of the user nations and are only lent to industry for the duration of the trials; this is why each partner nation provided one: the British ISPA1 and the Italian ISPA2 from Tranche 1, and the Spanish ISPA3, the Italian ISPA4 and the British ISPA5 from Tranche 2.

ISPA4 was the second Italian instrumented series production aircraft. It is a single-seat F-2000A of Tranche 2, construction number IS038, which first flew under the provisional test registration CSX7306 and later received the definitive military serial MM7306. It was delivered in May 2011 as a Tranche 2 aircraft and assigned to the PIRATE and inertial navigation system test campaign; Italian sources summarise its task as the development of the FLIR function. PIRATE (Passive Infrared Airborne Track Equipment) is the Typhoon's infrared sensor, combining a forward-looking infrared (FLIR) function with infra-red search and track (IRST); it is mounted on the port side of the fuselage ahead of the windscreen and is produced by the EuroFIRST consortium, in which Italy's Leonardo is the lead contractor and design and technical authority alongside Thales Land & Joint Systems of the United Kingdom and Tecnobit of Spain. That the sensor test-bed fell to the Italian partner follows from this industrial leadership: PIRATE flight testing had begun in 2001 with trials of the FLIR function on flights between Turin and Sardinia, and the first Typhoon fitted with the sensor was a Tranche 1 Block 5 aircraft delivered to the Aeronautica Militare in August 2007. ISPA4 carried that line of work onto a Tranche 2 airframe, with its new computers and avionics, at the point where the integration of the sensor with the cockpit displays and with inertial navigation required a series aircraft representative of the standard the air forces would actually receive.

Once its test duties were complete, the aircraft was handed over to the Aeronautica Militare in January 2014, where it has served as a line F-2000A with the code 37-18 in the 18° Gruppo of the 37° Stormo. Photographic records also show it wearing the code RS-21 while operated by the Reparto Sperimentale Volo (311° Gruppo), the Italian Air Force's flight test unit, and on deployments and displays outside Italy, such as Leeuwarden in the Netherlands in September 2011, still in its test phase, or Fairford in the United Kingdom once in service. The career of ISPA4 illustrates the ISPA ownership model: the same aircraft passes from industry test-bed to the air force's experimental unit and finally to an operational squadron, without the user nation ever giving up title to the airframe.