Typhoon receives formal release to service certificate, freeing the aircraft from restrictive flight limitations


The Royal Air Force's Eurofighter Typhoon has received its formal release to service (RTS), freeing the UK's first Tranche 1, Batch 1 production aircraft from restrictive flight limitations imposed late last year under its Case White introduction to service programme with BAE Systems.


Signed on 13 May, the RTS document clears the aircraft for service instructor pilot training, operational test and evaluation and operational conversion unit syllabus validation activities.


An RTS recommendations report was presented on 30 April by the UK's QinetiQ test and evaluation agency which had been contracted to conduct an eight-month assessment of the Typhoon's operational readiness.


The aircraft was initially operated under temporary restrictions that combined airworthiness flight limitations identified by the four-nation Eurofighter consortium with additional limits imposed by the UK Defence Procurement Agency's Typhoon Integrated Project Team (IPT).


According to Ministry of Defence sources, the QinetiQ report identified three areas of concern which could have halted the release of RTS approval, although two of those could be adequately mitigated by imposing operational limitations.


QinetiQ found the aircraft's low-speed warning system was ineffective when used with the manual low-speed recovery procedure, while head-up display limitations made it difficult for pilots to manage the aircraft's energy state during dynamic manoeuvres.


The agency believed these flaws  could lead to the aircraft decelerating to a speed at which its flight control software would be unable to stabilise the aircraft, risking an "irrecoverable departure".


It is also understood to have warned of software bus failures, with the potential loss of all flight reference information, and to have recommended that two pilots operate the aircraft when in instrument meteorological conditions.


Another concern centred on the Typhoon's landing gear computer which, it says, has experienced a series of unpredictable failures leading to spurious landing gear indications and a loss of braking.


Partly as a result of the QinetiQ study, "the Typhoon has been modified, procedures reviewed and limitations put in place", the RAF tells Flight International. No crewing restrictions were imposed in the RAF's final RTS approval and sources close to the Typhoon IPT say the document provides a level of safety unparalleled during earlier fighter acquisitions.


"The RAF has been operating its Typhoons quite aggressively since December 2003 and there are no restrictions affecting the operational evaluation unit's work," says a BAE source. Nor have the UK's partners in the Eurofighter project - Germany, Italy and Spain - imposed limitations on their aircraft as a result of the UK safety study, the source adds.


The first Typhoon to fly in the markings of the RAF's 29(R) Squadron operational conversion unit conducted its debut sortie from BAE's Warton manufacturing site on 20 May.




Source: Flight International