General Electric and Safran Group are to collaborate on development of a viable open rotor engine, ‘RISE’, destined to power narrowbody aircraft by the mid-2030’s. The joint venture between the US and French aero engine giants intends to make workable a concept first touted in the 1970s. The open rotor engine dispenses with the traditional pod housing the fan blades seen on high bypass turbofan engines.
The original development of open rotor engines, also known as ‘propfans’ and ‘unducted fans’, never truly gained traction due to several key disadvantages. These ranged from issues with excessive noise to business and economic constraints at the time. In a new era of environmental limitations and pandemics, could the targets aviation has set itself for the next decade prove the perfect breeding ground for the open rotor?
There have been significant advancements in gas turbine technology over the last decade in a bid to reduce engine fuel consumption, most notably the Pratt & Whitney Geared Turbo Fan, Trent XWB and CFM LEAP engines. Aircraft fleets data from IBA’s InsightIQ currently shows 1,090 active aircraft globally powered by CFM LEAP family engines, all of which are Boeing, Airbus or COMAC types. The constant requirement to reduce emissions further has driven investment into developing more disruptive technologies within this aircraft class - enter the open rotor concept.
Concepts for application of the open rotor jet engine. Image: CFM
The open rotor engine aims to reduce fuel consumption by 20% and to reduce noise when compared against conventional gas turbine engines. The project tests key aspects in the design that included aero-acoustic optimisation, pitch control systems, contra-rotating reduction gearbox, lubrication and cooling systems as well as the rotating parts within the nacelle. Notably, noise issues were one of the key barriers to the success of the original open rotor development. The finished product would also be compatible with Sustainable Aviation Fuels, as well as potential Hydrogen fuel capability.
IBA believes the open rotor has the huge potential to disrupt and change the engine market - though it should be noted that with delivery not expected until the middle of the next decade, timelines may prove problematic for some OEMs.
The open rotor GE36 on a McDonnell Douglas MD-80 demonstrator at the 1988 Farnborough Air Show. Image: Andrew Thomas
IBA is an award-winning and leading independent aviation consultancy advising a broad mix of lessors, operators, financiers and investors. Operating globally, we inform decision-making and support operations across the aviation spectrum. Supporting strategic investments, managing aircraft, advising on expansion, or driving efficiency improvements, our mix of intelligence gathering, analysis, proprietary data, technical expertise and decades of aviation experience delivers value across aviation opportunities and challenges.
IBA’s InsightIQ analysis platform flexibly illustrates multiple asset, fleet and market positions, actual and potential, to inform client choices and identify acquisition opportunities. Immediate access to crucial aircraft, engine, lease rate and fleet data eases appreciation of historic and future aircraft concentrations and operator profiles.
As the aviation industry begins to wake from its slumber in a post Covid-19 landscape, many of us have wondered what the future holds for new aircraft technologies. How will the leading OEMs and their respective stakeholders address commitment to a carbon neutral aviation industry by 2050? In recent years, development of battery-powered aircraft concepts has continued, various new start up ventures exploring this propulsion technology, its possible applications and the regulatory hurdles and infrastructure challenges battery-powered aircraft face. There have been no concrete commitments to purely electric aircraft by the leading OEMs owing to the energy density (or lack thereof) vs weight penalties inherent in flying intercontinental routes. This, however, doesn’t mean there isn’t a place in the market for electric propulsion; it has great potential for short regional flights with smaller capacity cabins operating out of airports and aerodromes that would typically not accept commercial traffic.
For CFMI, it would appear that the impact of the 737 MAX grounding has not been detrimental to the LEAP-1B. There remains a strong market outlook for this engine and looking at the Base Value, Half Life, it is performing well and is on par with competing engines in the market. As illustrated in the chart below, there has been no impact on values.