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Aviation History
1993
1993 - 1531.PDF
aspect ratio on the Eurofighter 2000 wing is 2.205, compared with the EAP's 2.4, to maintain low supersonic-straight-line and manoeuvre drag. Despite US military manufacturers' preference for keeping "foreplanes on other people's aircraft", the Eurofighter has retained the EAP's canard configura tion. Coupled with a quadruplex digital flight-control system (DFCS), unstable canards provide a subsonic manoeuvre- performance envelope similar to that of a conventional configuration. At supersonic speeds, a canard configuration is more efficient in manoeuvre, with the added advantage of leaving the rear fuselage clean and reducing after body drag. The foreplane area has been reduced, from 3.81m2, to 2.40m2. Pitch-and-yaw control is maintained via the foreplanes combined with the inboard and outboard flaperons on the trailing edge. The rudder provides yaw control. Two-segment leading edge slats, config ured automatically by the DFCS, provide optimum wing camber throughout the angle-of-attack envelope. The Eurofighter's relaxed stability, a pre-requisite for meeting agility demands enshrined in the European Staff Require ment-Draft (ESR-D), necessitates the use of a full-authority digital, rather than conventional, DFCS. The DFCS is being developed by GEC Marconi Avionics (GMAv) and DASA, with the latter acting as team leader. The full-authority quadruplex FCS provides the pilot with "carefree handling" and will also include a "panic button", a feature of current Russian combat aircraft. If a pilot feels that he is moving outside the air craft's envelope in an uncontrolled fash ion, hitting the panic button will return tics Two headlines from Flight International in 1985 read: "EFA — will it hap pen?" and "Last chance for EFA". It was a difficult year for the project. The past 12 months have, if anything, been worse. German coffers for this year are now empty. At least DM300 million ($190 million) needs to be found to tide the programme over. To the delight of German voters, Ger man defence minister Volker Ruhe has appeared determined to drag the Eurofighter to the edge of the abyss and kick it over. UK defence secretary Malcolm Rifkind seems willing to strap his political repu tation to the EFA and deflect Ruhe from his chosen path. Meanwhile, the defence ministers of Italy and Spain remained on the side lines. Ruhe tried to co-opt both by suggesting that they also wanted to dump the EFA. In response, the Italians sent a high-level missive saying that RUhe was mistaken. The outcome of Ruhe's manoeuvring was described by one official as "a name- changing exercise". The EFA was dead. Long live the Eurofighter 2000. Ruhe could wrap himself in the Emperor's new clothes and claim that he had killed the EFA. Costs were reduced, with the Ger man aircraft being stripped of some offen sive and defensive systems. The Eurofighter 2000, however, cannot be called a new aircraft — even by the stretch of a wildly fertile imagination. ^ Industrial and defence ministry studies, launched in the wake of the December meeting, respectively re-examined work share and production and the military requirement. On the industry side, the suggested changes in production mark merely a sensible rationalisation of an arcane and politically driven manufactur ing approach. Anyone who thought that the pro gramme was back on an even keel follow ing the four-nation ministerial meeting on 10 December, 1992 — which agreed the launch of the Eurofighter 2000 — was sadly mistaken, however. Ruhe has continued to snipe at the project, squeezing the budget and refusing to provide more funding. He has done this despite unilaterally giving up DM300 mil lion by setting an unrealistically low 1993 budget. Ruhe and industry, in the shape of German prime contractor Deutsche Aerospace, are discussing how to sur mount this manufactured hurdle. In the short term, industry is likely to have to find at least 50%, with the defence minis try pulling the rest from other projects. The Eurofighter has proved an ex tremely resilient project. Once again, it has survived against the odds, this time helped by Rifkind. Having staked his political credibility on the Eurofighter, Rifkind is now keen to see the aircraft fly. If it does not do so soon, this year may only have provided a stay of execution. the aircraft to straight-and-level flight. The DFCS will also provide gust allevi ation, which is of particular importance in low-level flight regimes, where the ride quality for the pilot is improved, thus reducing fatigue. The four-nation Eurojet EJ200 will make its debut on Eurofighter DA3 Software for the DFCS is being written in the standard computer programming language for defence projects, Ada, with run-time critical sub-routines written in Assembler. Originally, the intention was to implement the complete DFCS in Ada, but concerns over its ability to meet time-critical performance needs saw a shift to Assembler in some areas. Effectively splitting development of the DFCS between DASA and GMAv, with the former carrying out the integration and the latter developing the software, raised eyebrows within industry when the ap proach was first revealed. Such a structure was the result of political requirements, with neither the UK nor Germany willing to surrender involvement in DFCS development. In the late 1970s, the UK had started to study this area with the Sepecat Jaguar fly-by- wire demonstrator programme, while Ger many worked on the Lockheed F-104 control-configured-vehicle project. Concerns over the management struc ture for the DFCS proved to be justified. The DFCS has been one of the main contributors to delays of the aircraft's first flight. Debugging of the FCS has proved particularly arduous. GMAv and DASA have pointed accusatory fingers at each other and at changing requirements. FLIGHT INTERNATIONAL 16 - 22 June, 1993
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