Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- Hopes for 1Q financial progress turns into bumpy ride for Boeing April 21, 2025
- Bjorn’s Corner: Air Transport’s route to 2050. Part 18. April 18, 2025
- Natilus: Composite BWB, entry-into-service by 2029, 570 on order April 17, 2025
- China bans Boeing, US parts imports in tariff war April 15, 2025
- Boeing welcomes COMAC competition as Asia-Pacific demand soars April 15, 2025
Bjorn’ s Corner: New aircraft technologies. Part 48. Maintenance Program for the A320/A321
By Bjorn Fehrm
March 1, 2024, ©. Leeham News: We are discussing the Operational phase of a new airliner family. For the operational phase, the airplane must pass scrutiny for Continued Airworthiness. The biggest item in a regulator’s Instructions for Continued Airworthiness is the required Maintenance program to keep an airliner airworthy. We discussed the modern MSG-3 maintenance program for an airliner last week, why it was created, and its main analysis principles.
Now we look at maintenance data designed to the MSG-3 standard, the Maintenance Planning Document (MPD) for the Airbus A318/A319/A320/A321.
Figure 1. The front page of the A318/A319/A320/A321 MPD no 45. Source: Airbus.
Bjorn’ s Corner: New aircraft technologies. Part 47. MSG-3 Maintenance
By Bjorn Fehrm
February 2, 2024, ©. Leeham News: We are discussing the different phases of a new airliner program. After covering the Design and Production, we now look at the Operational phase of a new airliner family.
For the operational phase, the airplane must pass scrutiny for Continued Airworthiness. The biggest item in a regulator’s Instructions for Continued Airworthiness is the required Maintenance program to keep an airliner airworthy. We started last week with how maintenance went from ad-hoc to a Hard Timed maintenance program in the late 1950s and early 1960s.
Figure 1. The maintenance manual for the Boeing 747. Source: Boeing.
Bjorn’ s Corner: New aircraft technologies. Part 46. Maintenance Program
By Bjorn Fehrm
January 19, 2024, ©. Leeham News: We are discussing the different phases of a new airliner program. After covering the Design and Production, we now look at the Operational phase of a new airliner family.
For the operational phase, the airplane must pass scrutiny for Continued Airworthiness. Today, we discuss the biggest item in a regulator’s Instructions for Continued Airworthiness: the required Maintenance to keep an airliner airworthy.
Figure 1. A typical maintenance program for an airliner. Source: ATR.
Bjorn’ s Corner: New aircraft technologies. Part 44. Operation and Continued Airworthiness
By Bjorn Fehrm
January 5, 2024, ©. Leeham News: We are discussing the different phases of a new airliner program. After covering the Design and Production, we now look at the Operational phase of a new airliner family.
For the customer, the design and production are exciting and interesting, but it’s the information and services around the operational phase (Fleet Support in Figure 1) of the airliner that are most important to the airline customer.
Figure 1. The development plan for a new airliner. Source: Leeham Co.
Bjorn’ s Corner: New aircraft technologies. Part 43. Delivery
By Bjorn Fehrm
December 22, 2023, ©. Leeham News: We are discussing the different phases of a new airliner program. After covering the Design, Prototype phase, and Production, we now look at the first deliveries.
After about seven to nine years of development and production preparation, it’s finally time for the first delivery of the new aircraft.
Figure 1. The development plan for a new airliner. Source: Leeham Co.
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.
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.
The Exception to the Green Propulsion Rule
Subscription required
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.
Further developments of the A321, Part 6
Subscription required
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.