Blue Whale Quad-tiltrotor [QTR]

The Quad-tiltrotor [QTR] "Blue Whale", a project revealed in 2013 by the China Helicopter Research and Development Institute, is among the more ambitious aircraft in the works, and not much has been heard of this project since around 2015. Different from CV-22 Osprey, Blue Whale will have four rotors. Able to tilt its four rotors from a horizontal to vertical position, it promises to reach speeds of more than 700km/h - which would make it the fastest "tiltrotor" in the world, 40 per cent faster than Boeing's V-22 Osprey, according to the institute. With a cruising speed of 538km/h, developers say the Blue Whale will lift 20 tonnes of cargo and fly more than 3,100 kilometres without refuelling. It will fly as high as 8,600 meters, also higher than the V-22.

The research on tilting rotorcraft in China started late, and many key technologies are still in the exploration stage. However, in addition to key technological breakthroughs, what is more needed is the bloom of innovation. In order to stimulate the innovative spirit of designers, the Helicopter Institute established the Director's Project Fund in 2009. The �Director Fund� is to support the application of basic research and key technology research, and to establish a good research environment, encourage original innovation, train helicopter high-tech talents, and promote helicopter technology advancement and development.

Chinese helicopter designers are focusing on the development of an ultrafast tilt-rotor aircraft capable of flying 500 kilometers per hour, the nation's top helicopter researcher said 21 December 2016. Wu Ximing, chief helicopter designer at State-owned aircraft giant Aviation Industry Corp of China, told China Daily that researchers at the company's Helicopter Research and Development Institute are developing the Blue Whale tilt-rotor aircraft, China's equivalent of the United States' Bell Boeing V-22 Osprey.

"We will design two variants of the Blue Whale - a medium-duty type and a heavy-duty one. The medium-duty model will have a maximum takeoff weight of 20 metric tons, and the heavy-duty model 40 tons. They can fly as fast as 500 km/h," Wu said. Modern helicopters usually have a maximum speed ranging from 250 to 300 km/h.

The aircraft will be able to conduct vertical takeoff and landing in tough terrain like a conventional helicopter, and will have a longer range and higher cruising speed that can compare to turboprop jets, Wu said, adding it can also carry heavier payloads than helicopters. With four rotors, the Blue Whale will have better reliability, maneuverability and safety than its US counterpart, the V-22 Osprey, he added.

Wu expected the tilt-rotor to conduct a wide variety of tasks, such as disaster relief, supply airdrop and other emergency response operations. AVIC sees the importance of developing the ultrafast tilt-rotor aircraft, he said, adding, however, that it will be a long time before they are ready for mass production due to the technological complexity. An earlier report by China Aviation News, a newspaper owned by AVIC, quoted engineers at the Helicopter Research and Development Institute as saying that the Blue Whale will have a flight range of 3,100 km and meet demands of rapid troop deployment of the Chinese army and navy.

The "Blue Whale" rotorcraft uses a four-tilt rotor configuration, with a flight speed expected to reach 700 kilometers per hour. The Blue Whale has a cruise speed of 538 kilometers per hour, can carry 20 tons of cargo, and can fly more than 3,100 kilometers with one refuel. Its practical ceiling is 8615 meters. With a combat radius of 815 kilometers, it has vertical take-off and landing capabilities, and has a backup power distribution unit in case of engine failure. The tilt-rotor is made of composite materials, has advanced photodynamic flight control systems, and "smart" avionics systems also help reduce pilot workload.

The successful development of the tilt-rotor aircraft in the last 30 years (Bell XV-15, Bell/Boeing V-22 and Bell/Agusta 609) make the tilt-rotor configuration a commercially viable starting point for efficient Vertical Take-Off and Landing (VTOL) aircraft. Tilt-rotor aircraft are aircraft which use the lift of rotors to hover and VTOL. These aircraft tilt their rotors so that in forward flight the lift is provided by the wing and the forward thrust by the rotors. The term "proprotor" can also be used to describe rotors that function as a propulsive device in forward flight and as lifting device in helicopter mode. The cruise efficiency of aircraft as measured by its payload carried times the distance traveled per consumed fuel (for example Lb of Payload.times.Mile traveled/Lb of consumed fuel) is proportional to the ratio between lift and drag of the aircraft in cruise.

In the concept of scientific research personnel, the "Blue Whale" adopts a retractable landing gear, with vertical take-off and landing and landing and landing ability, equipped with four engines, and the redundancy design ensures that the two engines can fly safely after failure. The distributed integrated avionics system is used to enhance mission capability and anti-jamming capability, and the optical transmission control system is combined with multi-modal mission flight control and intelligent integrated cockpit technology to reduce pilot load, greatly improve the proportion of composite materials applied, and have fault prediction and health management ability.

In addition to high speed, large loading, and long range, compared with conventional helicopters, "Blue Whale" also has the characteristics of small vibration, low noise, low fuel consumption and low transportation cost. In the "Blue Whale" structure, the rotor is placed at the tip of the wing away from the fuselage, and the diameter of the rotor is small, so the vibration level of the cockpit is lower than that of the conventional helicopter, and due to the main noise source - the rotor, away from the cockpit, Therefore, the noise in the cockpit is much smaller than that of a normal helicopter. Researchers have analyzed that when the "Blue Whale" hovered at a height of 150 meters, its noise is only 80 decibels, which is only equivalent to the noise emitted by trucks 30 meters away, which is especially suitable for passenger transportation. According to scientific research personnel, considering the advantages of �blue whale�, such as low fuel consumption, fast speed, large range and heavy load, the transportation cost is only 1/2 of that of conventional helicopters.

The tilting rotorcraft has both rotor and organic wings, and the rotor is tilted from a vertical position to a horizontal position or from a horizontal position to a vertical position. Therefore, it not only basically combines the technical features of the helicopter and the turboprop, but also has a rotor. Many technical features exist during the tilting process. Its structure, aerodynamics, control and other technologies are much more complicated than ordinary aircraft or helicopters, and it has various technical difficulties possessed by fixed-wing aircraft and helicopters, and also brings many unique technical problems of tilting rotorcraft. In summary, the technical difficulties of tilting the rotor mainly show that the aerodynamic interference of the rotor-wing has a great influence on the payload, the unsteady aerodynamic characteristics of the rotor tilting process is complex, the structural design of the tilting rotorcraft is complex, and the tilting rotorcraft is complicated.

Over the years, there is no further news about this aircraft.