Winner: Eurocopter
Location Marignane, France
Achievement Co-operative development of the advanced EC120 light helicopter with emphasis on very low levels of noise emission. Eurocopter's use of new technologies to create an advanced light helicopter with very low noise emissions, came to fruition in the first half of this year as the EC120 Colibri made its way through the final stages of European certification.
The five-seat, single-engined EC120 offers the lowest external noise levels of any civil helicopter, a fact that was recognised at the start of 1997 by a special award from the French environment ministry. The noise levels are 6.6dB below the legal limits set down by the latest regulations from the International Civil Aviation Organisation.
The use of new technologies was crucial to reducing noise, as well as making the EC120 one of the most advanced aircraft in its class.
A new main blade with thin tips and parabolic swept planform design helps to reduce noise from the main rotor system, while recent modifications to the cyclic gear train have given an 18dB abatement on the main gearbox.
The new-generation "spheriflex" articulated rotor head has also been used to minimise the number of main-rotor parts, with no roll bearings and so no lubrication.
The "quiet fenestron" enclosed tail-rotor system has also been incorporated into the EC120 design, helping to cut noise and increase safety from foreign object damage. The fenestron's rotor blades are spaced unequally, which helps to generate a phase modulation, so spreading out the acoustic energy over a wider range of frequencies.
Also to reduce noise, the air intake of the 376kW (504shp) Turboméca Arrius 2F engine has been installed under the upper fairing. Other new features include extensive use of composites throughout the airframe, including a completely composite tail boom.
Besides the noise-reduction technology, the Awards judges note that the project represents a major international collaboration, with the involvement of Chinese and Singapore aerospace industries as risk-sharing partners.
Finalist: Masquito Aircraft
Location Roosdaal, Belgium
Achievement Development of a ultra-light and low-cost, two-seat helicopter without any major backer
Stefaan and Paul Masschelein have certainly proved that the pioneering spirit is still alive and well in aviation. The two Belgian brothers, one an industrial designer and the other an electronics engineer, have set about developing and building a unique ultra-light helicopter, without any major outside help.
The result is the Masquito M58, an ultra-light, two-seat helicopter that uses a powerplant of only 48kW (64shp), the Rotax 582.
The prototype has only recently begun flight testing, but the 25h logged to date have confirmed the design validity. So far the helicopter has proved agile and extremely stable in hover, with surprisingly little structural vibration, which the designers believe is in part due to the high rotor revolution speeds.
Virtually all of the major components have been designed, fabricated and assembled by the two brothers, including main and tail rotors, using only their own experience and reference works on helicopter aerodynamics. No outside help has been brought in, partly because it is simply not readily available in Belgium but also because of the prohibitive cost for the fledgling Masquito Aircraft company.
Yet the M58 has shown an impressive power-efficiency and stability, as well as including some interesting design features. These include the composite laminar profile of its small-diameter 4.6m teeting main rotor; composite virtual-hinge rotor head with elastomeric collective pitch thrust bearings; hydraulically driven tail rotor, with built-in over-torque protection; and semi-reclined seating for pilot and passenger.
The Awards judges felt that the M58 represented an excellent innovation from a small but determined company.
Source: Flight International
