Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- The Boeing 767 Cross Section, Part 1 November 24, 2022
- Movie Review: Devotion November 21, 2022
- China will accelerate development of its commercial aerospace sector November 21, 2022
- Bjorn’s Corner: Sustainable Air Transport. Part 46. eVTOL comparison with helicopter November 18, 2022
- The economics of a 787-9 and A330-900 at eight or nine abreast November 16, 2022
Engine Development. Part 9. Gearbox or not?
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By Bjorn Fehrm
Introduction
October 13, 2022, © Leeham News: In our series, we look at the development of the latest single-aisle engines. Should these be geared? What do you gain and risk with a geared design? Is this a new development, or has it been around for a long time?
We examine the development of single-aisle engines since 2000, their fuel efficiency, and operational reliability.
Summary
- A geared design fixes some fundamental problems in a two-shaft turbofan.
- CFM proves you could just as well further develop what you have.
Pontifications: No engines, billions shy, devastating enviro analysis, Boom’s CEO still exudes optimism
By Scott Hamilton
Sept. 20, 2022, © Leeham News: Blake Scholl, the founder and CEO of Boom, the start-up company, continued to paint an optimistic picture about the Overture Supersonic Transport.
He told the US Chamber of Commerce Aerospace Summit last week that the Overture, a Mach 1.7 88-passenger aircraft concept, will revolutionize international air travel.
But Boom has big challenges ahead—not the least of which is that there is no engine manufacturer so far that has stepped up to provide an engine. The Big Three—GE Aviation, Pratt & Whitney, and Rolls-Royce—have either outright rejected participation or other priorities exist.
Plethora of Challenges
- Rolls says publicly it won’t pursue an engine for Boom. GE told LNA it’s not interested in developing an engine for Boom. P&W is focused on advances for its GTF, developing sustainable technology and military engines.
- The International Civil Aviation Organization (ICAO) in July issued a report on the environment that eviscerated SSTs and the SAF concept outlined for Boom. The report included analysis from the International Council on Clean Transportation (ICCT).
- Scholl claims a market demand for thousands of SSTs but Boom’s 2013 study by Boyd International forecast a market demand over the life of the program of 1,318 Overtures. Some thought this figure was generous.
- Boyd’s report also concludes Boom needs a Mach 2.2 airplane to be commercially viable. Scholl reduced the speed to 1.7. This means that in some cases, airline crews can’t do a round trip from the US to Europe without a relief crew, which upsets some of the economics.
- If Boom were a publicly traded company, all the orders would fall under the ASC 606 accounting rule that questions the viability of those orders.
- Scholl told AIN Online Boom needs $6bn to $8bn to come to market and so far, it has raised $600m.
- And we don’t get into the certification and regulatory hurdles. Among them: In his presentation to the Chamber, Scholl said there are 600 potential SST markets. He included some inland in the US, where there is a ban on SSTs flying over land.
De-carbonisation of air transport is ON
By Bjorn Fehrm
July 20, 2021, © Leeham News: Last week was a game-changing week for air transport. Three events synchronized to trigger it.
EU presented 13 policies to achieve net-zero greenhouse gas emissions by 2050 with concrete steps in-between. On the same day, the airframe and engine OEM’s CTOs said in a Farnborough Connect webcast: “It’s a commitment problem, not a technical problem to achieve the EU goals.”
This happened against a backdrop of European floodings, which made all discussions about climate change or not moot. Super-organized Germany lost over 100 persons to typhoon like rains, never seen before, that produced scenes like these: https://twitter.com/Aviation_Intel/status/1416215953080205321?s=20
Figure 1. Farnborough Connect, from top-left: Moderator Johnson, Boeing’s Hussein, GE’s Lorence, Rolls-Royce’s Stein, SAFRAN’s Dalbier, Raytheon Technologies’ Russel, and Airbus’ Klauke.
CFM announces the RISE engine program
June 14, 2021, © Leeham News: GE and SAFRAN took to the stage today to announce the extension of their CFM joint venture to 2050 and the CFM technology program RISE.
RISE stands for Revolutionary Innovation for Sustainable Engines, and it elevates previous work to new levels and introduces some news.
Figure 1. The RISE Open Rotor engine as presented by CFM. Source: CFM.