The National Aerospace Laboratory (NLR) has invented a convertible power control mechanism for use in the cockpits of tilt-rotor aircraft. The mechanism allows the rotor driving power (engine capacity) of this new type of aircraft to be regulated in different ways or modes. This is the first European patent granted to NLR.
With its rotating engine nacelles, each one containing an engine which drives a rotor, the tilt-rotor aircraft combines the best properties of airplane and helicopter. By turning the nacelles upward, the tilt-rotor can take off and land vertically like a helicopter, and does not require a runway. When the engine nacelles with rotors are slowly rotated forward, the tilt-rotor acquires the properties of a standard fixed-wing (turbo-prop) aircraft, with the associated speed and range.
One of the questions the developers must answer regarding the tilt-rotor aircraft is: who will fly the tilt-rotor aircraft? Will it be helicopter pilots or fixed-wing pilots? Pilots of commercial fixed-wing aircraft are accustomed to flying with a power lever that they move forward and backwards in a throttle box. Helicopter pilots, however, regulate the rotor power/thrust using a collective lever that they raise and lower. In order to convert from one mode of operation to the other, NLR developed a convertible power control, which allows the pilots to regulate the engine power and/or rotor thrust of the tilt-rotor aircraft in a ‘natural’way from helicopter to airplane mode or in-between (‘conversion’mode), or have it set fixed to the mode of operation they are accustomed to (i.e. fixed-wing airplanes or helicopters).
Since 2000, the European aviation sector has been working to develop a tilt-rotor aircraft for civil use, of a scale and size slightly smaller than the existing military Boeing V-22 Osprey, a tilt-rotor used by the US Marine Corps.
The aviation industry has expressed great interest in NLR’s invention. The granting of this patent adheres to the NLR’s general patent policy. In order to encourage NLR personnel to apply for patents, NLR has recently started offering bonuses to inventors.
This patent stems from research NLR conducts in the context of the NICETRIP project, which started in 2006, and in which NLR collaborates with various European research institutes and helicopter manufacturers in the development of a European tilt-rotor aircraft. NICETRIP stands for ‘Novel Innovative Competitive Effective Tilt Rotor Integrated Project’.
