May 3, 2024, ©. Leeham News: We do an article series about engine development. The aim is to understand why engine development now has longer timelines than airframe development and carries larger risks of product maturity problems.
To understand why engine development has become a challenging task, we need to understand engine fundamentals and the technologies used for these fundamentals.
We have in previous Corners discussed geared versus direct-drive turbofans. Now the time has come to discuss Open Rotor engines.
April 26, 2024, ©. Leeham News: We do an article series about engine development. The aim is to understand why engine development now dominates new airliner development when it comes to the needed calendar time and risks.
To understand why engine development has become a challenging task, we need to understand engine fundamentals and the technologies used for these fundamentals.
We discussed geared versus direct-drive turbofans last week. Now, we’ll examine some design problems for these engines.
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By Bjorn Fehrm
April 4, 2024, © Leeham News: Korean Air confirmed an order for 33 Airbus A350 in the week, 27 of which are the larger A350-1000. The order is significant on two accounts:
First, 27 A350-1000 and only 6 A350-900, where analysts have for years asked why the -1000 isn’t selling.
Secondly, for a carrier that has a rather 50-50 fleet of Airbus and Boeing planes, its large widebody was the Boeing 777-300ER, whereof it has 27 out of 37 Boeing 777 in total. Korean Air now chooses the A350-1000 to replace the 777-300ER. Why not the 777-9?
Was this a question of availability (the 777-9 should have been delivered in 2020 but has had several delays; the present plan says 2025), or was there a technical-economic reason for Korean Air’s decision? We examine the characteristics of the two planes to find the answers.
March 29, 2024, ©. Leeham News: We finished our article series about New Aircraft Technologies last week. It dealt with the different new technologies that a next-generation airliner could use to increase efficiency and by it environmental emissions.
An area that we touched upon but didn’t dig deeper into was engine development. When airframe development historically decided how long a new generation of aircraft took to develop, it gradually changed to engine development being the more calendar-time-consuming and riskier development for the last generations. This article series will discuss why and what can be done about it.
March 15, 2024, ©. Leeham News: We started the series a year ago about the New Aircraft Technologies that can be used when replacing our present single-aisle airliners.
We have covered a lot, including the typical development phases, from initial studies to preparing for the aircraft’s in-service phase.
Let’s make a resume of what we have discussed.
March 8, 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 discussed airframe maintenance in the last article. Now, we look at engine maintenance.
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.
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.
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.