Reviving supersonic passenger flights will 'harm the environment and create too much noise'

  • Three US-based start-ups are aiming to re-start ultra-fast flights by the 2020s  
  • The companies want to modify existing engines rather than make new ones  
  • But researchers say that these modified engines will cause harm to environment
  • There are also concerns that supersonic jets will create too much noise  

Reviving supersonic passenger flights will harm the environment, cause too much pollution and will be too noisy, according to a new study.

U.S based start-ups Aerion Supersonic, Boom Supersonic and Spike Aerospace are all aiming to re-start ultra-fast flights by the mid-2020s by modifying existing engines rather than spending billions of dollars to make new ones.

They hope to serve a market that has been dormant since Concorde, flown by British Airways and Air France, was retired from service in 2003.

Pictured is a British Airways Concorde that retired from service in 2003 after flying for 27 years 

Reviving supersonic passenger flights will harm the environment, cause too much pollution and will be too noisy, according to a new study. Pictured is a British Airways Concorde that retired from service in 2003 

However, a new study has claimed that reviving these jets will mean they are not likely to be able to comply with existing fuel efficiency.

The US-based International Council on Clean Transportation said that modified engines will burn five to seven times more fuel per passenger than subsonic jets, exceed global limits for new subsonic jets by 40 per cent for nitrogen oxide and 70 per cent for carbon dioxide.

The ICCT said, based on its study, that supersonic jet makers would be unlikely to meet environmental standards unless they used a new engine design with technology like a variable cycle that would operate differently at take-off than in cruise mode.

The alternative is for policymakers to ease standards for supersonic jets, the ICCT adds.

The United States is already pushing for different standards for ultra-fast planes but facing resistance from European nations that want tough rules on noise.

The Aerion AS2, the world's first supersonic business jet, is being developed by Lockheed Martin Corp partnering with plane maker Aerion Corp of Reno

The Aerion AS2, the world's first supersonic business jet, is being developed by Lockheed Martin Corp partnering with plane maker Aerion Corp of Reno

Daniel Rutherford, aviation director at the U.S.-based independent non-profit research organisation said: 'There are reasons to be worried about the environmental impact of reintroducing supersonic aircraft.

'A modest first step is for manufacturers to commit to meeting existing standards for new aircraft.

But finding an efficient engine for supersonic jets is tough in an industry that has for decades been catering to subsonic planes by improving fuel efficiency, expanding range and reducing noise through the use of larger fans.

Supersonic jets are most efficient at cruising altitude with smaller engines that are far noisier on takeoff, like those on fighter jets or old 727s that do not meet modern airport noise standards.

Smaller engines help reduce aerodynamic drag when flying above mach speed - the speed of sound.

Lockheed Martin Corp-backed Aerion has selected a GE engine core used in F-16 fighter jets and Boeing Co 737s as the basis for the engine on its planned jet, which will have a top speed of Mach 1.4.

Boom and Spike, which plan top speeds of Mach 2.2 and Mach 1.6 respectively, have yet to select engines.

Daniel Edgington-Mitchell, an aerospace engineering lecturer at Melbourne's Monash University, said: 'Even if you built something new, I think you are going to be struggling.

A British Airways Concorde after its last flight in 2003. It had a maximum speed over twice the speed of sound at Mach 2.04 (1,354 mph or 2,180 km per hour at cruise altitude) and could seat 92 to 128 passengers

A British Airways Concorde after its last flight in 2003. It had a maximum speed over twice the speed of sound at Mach 2.04 (1,354 mph or 2,180 km per hour at cruise altitude) and could seat 92 to 128 passengers

'I think that is why there is such a push in the United States to reconsider the standards particularly for supersonic aircraft because it is just going to be really difficult.'

Concorde, the last supersonic passenger jet, entered service in 1976 and continued flying for 27 years. It is one of only two supersonic transports to have been operated commercially.

It had a maximum speed over twice the speed of sound at Mach 2.04 (1,354 mph or 2,180 km per hour at cruise altitude) and could seat 92 to 128 passengers.

Concorde was jointly developed and manufactured by Aérospatiale and the British Aircraft Corporation (BAC) under an Anglo-French treaty.

Air France and British Airways each received seven aircraft.

Concorde was retired in 2003 due to a general downturn in the commercial aviation industry after the type's only crash in 2000, the September 11 attacks in 2001, and a decision by Airbus, the successor to Aérospatiale and BAC, to discontinue maintenance support.