Silent transporter

An ultra-quiet aircraft, capable of taking off from strips of land one tenth the length of conventional runways, could be used to provide air taxi services within cities, according to its UK developer.


An ultra-quiet aircraft, capable of taking off from strips of land one tenth the length of conventional runways, could be used to provide air taxi services within cities, according to its UK developer.


The Jetpod concept, the brainchild of London-based Avcen, is a Very Quiet Short Take-Off and Landing (VQSTOL) aircraft.


Although still at the design stage, Avcen believes the plane will be capable of taking off and landing within 125m. This will allow it to use small strips within city centres, where space is at a premium, and, as it is also capable of using stretches of grass or dirt strips, countryside locations where there is no proper runway.


To make it acceptable to city-dwellers, the aircraft also uses noise attenuation technologies, which can reduce the noise generated by the latest and quietest jet engines by an extra 17 to 20dB, according to Avcen managing director Mike Dacre.


‘The engines themselves are over-wing so you have obviously got some noise attenuation there, but most of the attenuation comes from the materials that we are using (to absorb acoustic energy) and the technologies we have developed to direct the thrust outside of the engine,’ said Dacre.


The firm has developed thrust management technology, including under-wing nozzles, to direct the thrust downwards through the wings. This reduces the amount of noise heard from the ground.


‘The thrust is in its standard horizontal mode as it goes out through the back of the aircraft, but it also goes through the wing as well,’ he said.


‘We call it thrust management, because it is managed after it comes out of the engine, that is where we take over. We do nothing to the engine, we take the thrust after it comes out of the mixer.’


The company believes the twin-jet, unpressurised aircraft will be capable of travelling at low altitudes at speeds of up to 300 knots (350mph), allowing it to transport people into London from out-of-town ‘park and fly’ sites in just two minutes. Demand for small aircraft capable of providing pay-on-demand transportation services into major cities is expected to rise as traffic congestion increases. To this end NASA is also leading its own Small Aircraft Transportation System (SATS) project.


The Avcen team, consisting of just five specialists, will now begin the proof-of-concept phase and build an aircraft ready for flight trials, the first of which is likely to be in around 18 months, said Dacre.


Once the basic concept has been proved, in terms of the noise produced, take-off and landing distances and flight speeds, the company will apply to the European Aviation Safety Agency in Cologne for certification. This process, which costs around e800,000 (£556,000) can take from five to seven years from first application.


Avcen has funding available to develop and trial the aircraft, but will need further investment to begin production.


The company has also designed concepts for a personal jet, as well military and unmanned versions of the aircraft. The military version could be used to transport commanders or wounded troops quickly to and from the front line, or for small Special Forces teams thanks to its low noise and ability to land in rugged conditions. It could also be launched from Aircraft Carriers without the need for a catapult or arrester, the company claims. A civilian air ambulance version of the aircraft has also been designed, which could land on cordoned-off hospital access roads rather than requiring a special strip.


The UAV design is capable of hovering, allowing it to be used to rescue someone while being controlled by a crew up to 300 miles away – an operation never attempted before.


An alternative unmanned version of the aircraft has also been designed to perform tasks such as light re-supply, construction and engineering repair while hovering alongside oil rigs, large ships and high rise buildings.



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