Leeham News and Analysis
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The Exception to the Green Propulsion Rule
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By Bjorn Fehrm
November 30, 2023, © Leeham News: The interest in Green alternative propulsion for airliners started in earnest at Farnborough Air Show 2014, where Airbus flew the E-Fan battery-electric aircraft. What followed was a dense stream of alternative propulsion airliner projects.
They all have in common that nothing much has come out of them. We have a Pipistrel two-seat trainer that can fly for 50 minutes on batteries, but not much else. More elaborate projects have wide slips in their plans, and nine years later, we lack real prototypes for all projects.
We have functional models flying for nine-seat hybrids and 19/30-seat hydrogen fuel cell aircraft that swap one engine for a Green alternative. Of the latter, there is one project that stands out from the rest. It has shown real progress over the last years and has realistic plans for a 55-seat hydrogen airliner that can be operational in three to four years.
We will analyze why the Universal Hydrogen ATR fuel cell project is the exception to the “Green Propulsion Rule,” that nothing comes out of all plans, and why it could be the first Green Propulsion airliner, ending a 10-year draught.
Figure 1. The Universal Hydrogen Dash 8-300 functional demonstrator. Source: Universal Hydrogen.
Summary:
- A Green Propulsion project means the airliner does not use hydrocarbon-burning (Kerosene or SAF) gas turbines.
- The project that breaks the rule that nothing seems to reach practical use this side of 2030 is the Universal Hydrogen ATR project.
Bjorn’s Corner: New aircraft technologies. Part 39. Production
By Bjorn Fehrm
November 23, 2023, ©. Leeham News: We are discussing the different phases of an airliner development program. After covering Conceptual, Preliminary, and Detailed design, the manufacturing of prototypes, and their roles in flight tests, we now look at production.
The focus and work around the production of an airliner has increased over the last decade. Why this renewed focus?
Figure 1. The development plan for a new airliner. Source: Leeham Co.
Bjorn’s Corner: New aircraft technologies. Part 38. Flight tests
By Bjorn Fehrm
November 17, 2023, ©. Leeham News: We are discussing the different design phases of an airliner development program. After covering Conceptual, Preliminary, and Detailed design and the manufacturing of prototypes and their roles, we now look deeper at the flight test phase.
Figure 1. The flight test fleet for the certification of a new airliner. Source: Leeham Co.
Bjorn’s Corner: New aircraft technologies. Part 38. Flight test aircraft
By Bjorn Fehrm
November 10, 2023, ©. Leeham News: We are discussing the different design phases of an airliner development program. After covering Conceptual, Preliminary, and Detailed design, we now discuss prototype manufacturing and testing.
Today, we look at the different flight test aircraft needed and their roles.
Figure 1. The development plan for a new airliner. Source: Leeham Co.
Bjorn’s Corner: New aircraft technologies. Part 37. First flight test prototype
By Bjorn Fehrm
November 3, 2023, ©. Leeham News: We are discussing the different design phases of an airliner development program. After covering Conceptual, Preliminary, and Detailed design, we now discuss prototype manufacturing and testing, Figure 1.
Today, we look at the role of the first flying prototype.
Figure 1. The development plan for a new airliner. Source: Leeham Co.
Bjorn’s Corner: New aircraft technologies. Part 36. Prototype manufacturing and Testing
By Bjorn Fehrm
October 27, 2023, ©. Leeham News: We are discussing the different design phases of an airliner development program. After covering Conceptual, Preliminary, and Detailed design (Figure 1), we now discuss prototype manufacturing and testing, where we today go deeper into structural testing.
Figure 1. The development plan for a new airliner. Source: Leeham Co.
Bjorn’s Corner: New aircraft technologies. Part 35. Prototype manufacturing and Testing
By Bjorn Fehrm
October 20, 2023, ©. Leeham News: We are discussing the different design phases of an airliner development program. The typical phases and their time use and manning are described in the Gant chart in Figure 1.
After covering Conceptual, Preliminary, and Detailed design, we now discuss Prototype manufacturing and Testing.
Figure 1. The development plan for a new airliner. Source: Leeham Co.
Bjorn’s Corner: New aircraft technologies. Part 34. Design for Certification
October 13, 2023, ©. Leeham News: We are discussing the Detailed design phase of an airliner development program. We have discussed program management methods, development techniques, tools for Detailed design, that improved production methods are as important as improved technology, and that the interaction with the suppliers is key.
But another consideration that affects detail design is the influence of the Certification process. Certification has a major influence on the program work in every step of the aircraft program.
Figure 1. The online version of the FAA 14 CFR Part 25 Airliner Airworthiness regulations. Source: US CFR.
Bjorn’s Corner: New aircraft technologies. Part 33. Supply chain
By Bjorn Fehrm.
October 6, 2023, ©. Leeham News: We are discussing the Detailed design phase of an airliner development program. We have discussed program management methods, development techniques, tools for Detailed design and that the production methods today are as important as technology for achieving aircraft performance.
Another decisive part is how to involve and manage the suppliers to a project. The supply chain contributes about two-thirds of the value of an aircraft. Methods and tools to control this part of the project are therefore critical for the program.
Figure 1. The development plan for a new airliner. Source: Leeham Co.
Bjorn’s Corner: New aircraft technologies. Part 29. Detailed design
By Bjorn Fehrm
September 8, 2023, ©. Leeham News: We described the Preliminary design phase of an airliner development program over the last weeks. Now our project is transitioning into Detailed design.
It’s the most challenging part of the project as we now go from perhaps a thousand people involved at the OEM into tens of thousands and even more people at consultancies and suppliers.
Figure 1. A new airliner family development plan. Source: Leeham Co.