EUROPEAN TILTROTOR PROGRAMME
Beginning in 1987, the European Commission sponsored feasibility and definition studies for a tiltrotor transport, then known as EuroFAR. It was hoped by Eurocopter that this ground-work could be incorporated in a forthcoming venture, announced in October 1998, for which other European partners were sought. Eurocopter envisaged a 19/20 seat aircraft with an MTOW of 25,000 kg (55,116 lb) and a service-entry date of around 2015. In early 1999 it undertook a study, sponsored by the French defence ministry, into the military potential of tiltrotors.
By 1999, 33 companies from nine European countries had joined with Eurocopter to apply for EC funding, initially to build a test rig for a proposed 10,000 kg (22,046 lb), 12/19-seat tiltrotor, provisionally known as Eurotilt. Envisaged shares in the project, which could have led to a prototype flying in 2004-05 and entry into service in 2008, included France 36 per cent, Spain 25.7 per cent, Germany 22.3 per cent and Italy 11.6 per cent. Work-shares included Fiat Avio for transmission, CASA for wings and Rolls-Royce Turbomeca for RTM 332 engines. Performance parameters were 300 kt (556 km/h; 345 mph) cruising speed over ranges between 200 and 800 n miles (370 and 1,481 km; 230 and 920 miles) and a service ceiling of 7.620 m (25,000 ft). Development cost (1999) estimated as US$1.05 billion, of which US$87.5 million for ground test rig.
Meanwhile, in July 1999, Agusta announced the 10-tonne, 20-seat Erica Tiltrotor and was seeking €90 million of funding from EU's 5th Framework research programme to build a ground test vehicle (GTV). Testing was envisaged five years after GTV go-ahead; prototype first flight in further two years. Backing received from 16 companies, including GKN Westland (UK), ZF Luftfahrttechnik (Germany), IAI (Israel), Aermacchi (Italy), NLR (Netherlands), Gamesa (Spain) and Saab (Sweden).
Erica was second-generation tiltrotor, incorporating improvements over BA609 and V-22. Engines mounted inboard, underwing, driving connecting shafts to proprotors at wingtips. outboard half of wing was to tilt with proprotors, obviating blocking effect of fixed wing and increasing vertical lift by 12 per cent. This improvement would permit smaller proprotor diameter, increasing cruising speed and allowing almost conventional rolling landings, with outboard wing tilted by only 5 to 7° to prevent ground contact.
In October 1999, European Commission rejected separate funding of competing European tiltrotors and urged merger of Erica with Eurotilt.
Common research project, known as 2Gether (second-generation European tilting highly efficient rotorcraft), submitted to European Commission on 31 March 2000 by Eurocopter, Westland and Agusta (since merged as AgustaWestland). Timetable envisaged initial €95 million study between 2000 and 2004, followed by demonstrator first flight in 2005 (additional €250 million) and production programme (€1,000 million) leading to series manufacture beginning in 2010. Launch version would have had 10-tonne MTOW and carried 20 passengers.
European Commission rejected 2Gether as too costly and insufficiently innovative. New development proposal submitted in March 2001; cost €40 million to €60 million, with industry providing half; features tilting outer wing, as proposed by Agusta; early research devoted to overcomming additional technical difficulties of this configuration; flight demonstration could begin in 2007-08. Study team also to include Mecaer and Teleavio of Italy; Gamesa and Sener of Spain; UK's FHL; ZF of Germany; ONERA, DLR, NLR and CIRA research institutes; Israel Aircraft Industries; and Pratt & Whitney Canada. These joined by Flight Science and Technology Laboratory at Liverpoll University, UK, which inaugurated in June 2001 a flight simulator to be used in developing a control system for Eurocopter's Eurotilt submission.
Various research efforts merged into RHILP (Rotorcraft Handling qualities, Interaction and Load Prediction) project, combining Eurocopter (in France) and Eurocopter Deutschland, plus research organisations CIRA (Italy), DLR (Germany), NLR (Netherlands), ONERA (France) and University of Liverpool (UK). Evaluation and risk-minimisation project began March 2000 and so far embraces four work packages; WP1 for handling qualities definition, employing moving base simulator at Liverpool (first four with Bell XV-15 parameters, but progressing to Eurotilt in August 2002); WP2 analysing specific flight phenomena using 1:7 scale model at Eurocopter, Marignane; WP3 for loads alleviation; and WP4 use of Marignane's SPHERE simulator for piloted simulation tests. Completion due in 2003, although RHILP is only one of several Critical Technology Projects envisaged up to 2005 and its results will be incorporated in HOST flight mechanics software configured to represent Eurotilt.