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.
April 12, 2024, ©. Leeham News: We have started an article series about engine development. The aim is to understand why engine development now dominates the new airliner development calendar time and the risks involved.
To understand why engine development has become a challenging task, we need to understand engine fundamentals and the technologies used for these fundamentals. We started last week with thrust generation, now we develop this to propulsive efficiency.
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.
Subscription Required
By Chris Sloan and Gordon Smith
January 11, 2033, © Leeham News: In 2023, a slew of problems plagued propulsion providers, with Pratt & Whitney’s GTF Engine and supply-chain shortcomings grabbing the bulk of negative headlines and customer complaints. There were bright spots for all the big three with a slew of significant orders, emerging technologies, and critical management shifts.
As the calendar turns to 2024, all eyes will be on a return to fulfilling enormous backlogs, supporting OEM production rate increases, and returning GTF-propelled planes to the skies – while edging towards new technologies, both incremental and revolutionary.
Editor’s Note: As Airbus and Boeing consider new airplanes, their current generation aircraft are plagued with technical issues. The engines on the A320neo and 737 MAX families continue to have problems years after entry into service. The Boeing 787, which had ground-breaking technology when it was designed, has production issues. Flight testing early on revealed technical problems with the engine on the 777X, prompting the president of Emirates Airline to publicly suggest he won’t accept delivery until the engines are fully “mature.”
Aviation Week’s Check 6 podcast last week examined Boeing’s path toward a new airplane. Boeing CEO David Calhoun insists on waiting for new technology. But “new technology,” while in theory is a great idea, the phrase also scares people. LNA reported on this in March 2020. We’re reposting this article from then.
Related Stories
Now Open to All Readers
Subscription Required
By Scott Hamilton
March 16, 2020, © Leeham News: “I can tell you from our perspective, we’re kind of sick and tired of new, new technology. It’s not proven to be the home run.”
This blunt assessment comes from the chief executive officer of the big aircraft lessor, Avolon.
Domhnal Slattery, the CEO, was giving his critique of whether Boeing should launch a new airplane once the 737 MAX crisis is over. (Update: Since this interview, Slattery retired from Avolon.)
Boeing was on a path to decide whether to launch the New Midmarket Airplane when the MAX was grounded one year ago this month.
Airbus was waiting for Boeing to move before deciding how to respond.
Subscription required
June 16, 2023, ©. Leeham News: This is a complementary article to Part 17. Airframe with lower induced drag. It discusses in detail the simulations we have done on a Truss Braced Wing, using our Aircraft Performance and Cost model to compare it to today’s wings and alternative future concepts.
May 30, 2023, © Leeham News: “The need for radical fuel improvements will only increase over time.”
That’s the definitive conclusion of Arjan Hegeman, GE Aerospace’s general manager of advanced technology.
GE is working on Performance Improvement Packages (PIPs) of its current engine lineup used on Airbus and Boeing airliners. It’s also developing the GE9X, now in testing on the Boeing 777X, and concepts of a hybrid-electric and hydrogen-fueled engine.
But the big bet is on the Open Fan “RISE” (Revolutionary Innovation for Sustainable Engines). “The Open Fan technology—it’s a go,” Hegeman declared earlier this month at a press briefing in advance of the Paris Air Show next month.
The Open Fan is an evolution of the Open Rotor engine tested in the 1980s. The concept shows a dramatic reduction in fuel consumption compared with the engines of the day. But the counter-rotating rotor design was very noisy. Coupled with other technical challenges and a sudden drop in fuel prices, GE (and rival Pratt & Whitney) dropped the concepts.
But research and development continued. Today, PW thinks its Geared Turbo Fan engine will suffice for the future. Rolls-Royce is also pursuing traditional engine designs. But GE believes the problems of the Open Rotor have been solved for the Open Fan.
How?
It comes down to supercomputing, said Mohamed Ali, GE Aerospace vice president of engineering.
May 9, 2023, © Leeham News: Last week, I provided an overarching view of the business model the engine makers used for decades to sell their engines and services to the airlines and leasing companies. Today, we discuss this in more detail and move to other issues facing engine makers as well.
Aviation Week’s MRO Americas last month was the venue for the engine panel.
Related article
The panelists include two from the manufacturers, Becky Johnson, I’m the Director of Marketing for CFM commercial programs at GE Aerospace, and Sam Raby, who is Associate Director at Pratt & Whitney for aftermarket marketing and strategy. Two other panelists were from the MRO sector: Russ Shelton, president of GA Telesis Engine Services, and Sebastian Torhorst, Head of Sales for Energy Services for the Americas for Lufthansa Technik.
As LNA wrote last week, the business model relies on selling engines at a steep, steep discount—sometimes up to 80%, and in rare instances, the engine maker gave (as in free) engines to customers. In either case, the quid pro quo was to enter into long-term service contracts for parts and maintenance, repair and overhaul (MRO). Deeply discounted sales meant it could take 10-15 years for the engine makers to recover development costs.
Subscription Required
By Scott Hamilton and Bjorn Fehrm
May 8, 2023, © Leeham News: India’s GoFirst Airlines filed for bankruptcy last week. The carrier pointed to around 29 of its 50 Pratt & Whitney Geared TurboFan-powered Airbus A320neos being grounded as the reason.
The aircraft have been grounded for months. Despite negotiations with PW and a favorable arbitration ruling, GoFirst says PW failed to provide replacement engines. As a result, GoFirst paid about $196m in lease rates for the grounded aircraft, without being able to fly them for revenue.
Lufthansa Group last week complained that a third of its Swiss Airbus A220 fleet, also powered by the GTF, are likewise grounded with technical issues. As LNA previously reported, Air Baltic, Egyptair and Air Senegal also have A220s grounded. Iraqi Airlines has some A220s that are grounded. And now there’s news that Embraer E195-E2s at KLM’s regional airline are also grounded due to GTF issues.
India’s Indigo Airlines also has a large number of A320neos grounded with GTF problems. About 11% of the nearly 3,000 A320neos in service are grounded or fly one a week, an Aviation Week analysis revealed.
PW’s reputation was already badly damaged before the GoFirst bankruptcy. However, an LNA analysis shows that forward orders for engines on the A320neo already were suffering.
Summary
Related Articles