VIVAERO

Cranfield Arospace: Say hello to hydrogen!

The unveiling of a newly refurbished hangar at Cranfield Aerospace Solutions marks a new step in its progress to net zero flight. Ed Hill was at the opening ceremony to find out more.

The development of greener forms of flying is a challenging task. Replacing combustion power that has been part of its evolution from the outset means a complete transformation in engine design, fuel types, and aircraft configurations; made even more difficult with net zero targets that impose stringent timescales.

Any organisation taking on this challenge must think hard about what is achievable, practical, and importantly profitable. This approach seems to encapsulate Cranfield Aerospace Solutions’ (CAeS) philosophy when it comes to what it calls Project Fresson. 

The project, partly funded by the Aerospace Technology Institute, aims to replace the existing piston/turboprop powered engines used on the Britten-Norman Islander sub-regional STOL nine-seater aircraft, with hydrogen fuel cell electrical power.

At the newly refurbished hangar on the Cranfield University site, where much of the development work on Project Fresson is being carried out, Paul Hutton, CEO of CAeS, outlined how the task was progressing.

“We decided to take the research and development capabilities that we normally use on behalf of large OEMs and develop our own product,” he begins. “We wanted to develop an environmentally friendly solution, so our first consideration was what type of aircraft would be a credible option to start with?”

There were many reasons why the Islander fits the bill. Firstly, it’s a well-proven light utility aircraft (with its origins dating back to the sixties) used for multiple uses around the world. In fact, the twin-engined workhorse has accumulated more than 20 million flight hours providing vital services to remote communities. Secondly, it’s in the 9-19 passenger size platform where Cranfield believed there were already credible technical solutions to provide net zero power, and thirdly, currently around 85% of the flights that it makes (for example, hopping from one island community to another) are under 60 minutes.

“The first step on this process will be very challenging, whatever technology you choose,” Hutton says. “We rejected an eVTOL option because you don’t have the benefits that wings give you in getting into the air. We considered the best alternative was a sub-regional aircraft because that would attract interest and investment from the market, and lastly it is a segment with fewer competitors.”

Cranfield also believe that as a relatively overlooked market, many of the existing aircraft servicing it are older and in need of replacement.  

Options, options...Initially Cranfield considered an electric, battery powered version to replace the engines on the Islander, but as the calculations were made, it became clear that this would not be operationally viable.

“We considered batteries to give us 60 minutes of flight with 45 minutes reserve, in fact with that option we wouldn’t even be able to make the reserve,” explains Hutton.

Other options such as a hybrid power source with a battery and engine range extender were also proposed but with the added weight this would also substantially reduce the aircraft’s range and would still produce some CO2 emissions.

“There are advocates in the net zero aviation space, who say a particular technology is the only answer, but we are most concerned about what will practically work on an aircraft that is sustainable.

“We chose the Islander because it demonstrated it was likely to have a realistic commercial application, which means it is more attractive to buyers and we can attract the investment required. That is also why we chose hydrogen fuel cell technology with hydrogen gas as the fuel, because it is the best pragmatic solution.”

In the Islander’s case, Cranfield believe the gas – as opposed to liquid hydrogen fuel – offers more benefits, not just for the aircraft but for the convenience of the infrastructure needed to support it.

https://cranfieldaerospace.com