Bjorn’s Corner: New aircraft technologies. Part 42. Improving the learning curve

By Bjorn Fehrm

December 15, 2023, ©. Leeham News: We are discussing the different phases of a new airliner program. After covering Conceptual, Preliminary, and Detailed design, the manufacturing of prototypes, and their roles in flight tests, we now look at the production phase.

Last week, we discussed why production costs vary over time and why they can be up to 500% higher for the first units than for units past 400 to 500 aircraft produced. Now we go deeper into the reasons behind this and what can be done to improve the situation.

Figure 1. The program plan for a new airliner. Source: Leeham Co.

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Bjorn’s Corner: New aircraft technologies. Part 41. Production learning curve

By Bjorn Fehrm

December 08, 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.

Last week, we explained why aircraft projects often fail 100 to 200 aircraft into production. What’s not well understood is the effects of production learning on product cost.

Figure 1. The development plan for a new airliner. Source: Leeham Co.

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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.

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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.

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Further developments of the A321, Part 6

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By Bjorn Fehrm

November 23, 2023, © Leeham News: We do an article series about what can be the subsequent development for Airbus’ most popular aircraft, the A321neo. We looked at different changes to the aircraft in previous articles and the economics in short haul configuration. Now, we compare the capacity and economics of the different variants when configured for long-haul missions.

We use our Airliner Performance and Cost Model (APCM) to look at passenger capacity, seat-mile costs, and range.

Summary:

  • A stretched A321 is limited as a long-haul aircraft, as it needs additional fuel and additional takeoff weight to carry the fuel.
  • Long-haul variants of a stretched A321 will need the XLR center tank or the new, larger wing of an A32x to extend the range to long-haul values.

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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.

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Further developments of the A321, Part 5

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By Bjorn Fehrm

November 16, 2023, © Leeham News: We have done an article series about what can be the subsequent development for Airbus’ most popular aircraft, the A321neo. We looked at different changes to the aircraft in previous articles. Now, we compare the capacity and economics of the different variants.

We use our Airliner Performance and Cost Model (APCM) to examine passenger capacity, range, and seat-mile costs.

Summary:
  • The stretched A321s have improved operating economics.
  • The question is if the cost and time of the projects are motivated versus keeping the A321s “as is” and then make a clean sheet replacement.

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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.

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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.

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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.

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