Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- Bjorn’s Corner: Air Transport’s route to 2050. Part 19. April 25, 2025
- How good is the C929? Part 2. April 24, 2025
- Boeing First Quarter Results Update: China is 10% of the backlog, with 500 in “Unidentified” April 24, 2025
- Boeing First Quarter Results: Tariffs, Return flights, $10.55bn asset sale April 23, 2025
- RTX Q1 2025 Earnings: GTF Talk Takes A Back Seat To Tariffs April 22, 2025
Narrowbody and Widebody engine developments, Part 2
By Bjorn Fehrm
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Introduction
April 19, 2018, © Leeham News: In an article last week, we discussed the reason the new narrow-body engines are catching up to the fuel consumption of the wide-body engines.
Today we dig a bit deeper into the efficiency changes of the different engines and discuss which parameter changes have caused what changes in engine efficiency.
We will use our engine modeling software GasTurb to analyze what happens in a Turbofan when we change certain parameters.
Summary:
- The engine’s Core or Thermal efficiency changes with Turbine Entry Temperature (TET).
- To fully utilize such an increase in efficiency we need to adapt the overall design of the engine.
Déjà vu all over again
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Introduction
April 16, 2018, © Leeham News: There’s high turnover in the executive ranks. Major delivery delays cause disruption and unhappy customers. Airlines are cancelling and switching orders. Product strategy is challenged. Your competitor is taking advantage and making significant inroads.
If this sounds familiar, it is.
It’s déjà vu all over again.
FAA AD may severely limit ETOPS of some RR-powered 787s: sources
British Airways Boeing 787 without engines on the Boeing Paine Field line. Photo taken April 12 by Jennifer Schuld.
April 14, 2018, © Leeham News: An airworthiness directive from the US Federal Aviation Administration is expected as early as Tuesday that could severely restrict flight operations some of Rolls-Royce-powered Boeing 787s.
The AD is expected to require inspections and a reduction in the ETOPS long-range operation to 140 minutes from the nearest airport from 330 minutes, sources say. Inspections have to be made by May 20, according to preliminary information. If inspections fail, ETOPS may be reduced to 60, two airlines tell LNC. A third source didn’t have the numbers but said the AD is expected to be “onerous.”
Until the AD is issued and published, the numbers and conditions could change, one source tells LNC on background.
EASA, the European safety agency, issued its AD yesterday, with an April 20 effective date.
About 25% of the 787s are powered by Rolls-Royce engines, but not all engines are affected.
Narrowbody and Widebody engine developments
By Bjorn Fehrm
Subscription Required
Introduction
April 12, 2018, © Leeham News: In an article yesterday about Long-Haul LCC costs we observed how the new Narrowbody engines are catching up to the fuel efficiencies of the Widebody engines.
Traditionally the Widebody engines were the efficiency leaders. The Narrowbody companions were designed to be durable rather than efficient.
Figure 1. Cut through of the Narrowbody LEAP engine. Source: CFM
We use the engine modelling software GasTurb to understand why this catching up of the Narrowbody engines has happened.
Summary:
- The new Narrowbody engines for Airbus’ A320 series and Boeing’s 737 MAX are close in specific fuel consumption to the new Widebody engines.
- We use the GasTurb engine modelling software to find the root cause of this change.
Is Long-Haul LCC viable? Part 3
By Bjorn Fehrm
April 11, 2018, © Leeham News: In the second article if Long-Haul LCC is a viable business, we described the cost items which have to be part of a Revenue versus Cost analysis.
In a subsequent article, we used our performance model to develop the typical costs for the aircraft types we study. We now look at these typical costs, discuss their background and relative importance.
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Is Airbus’ A330-800 the longest range widebody under 300 seats?
By Bjorn Fehrm
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Introduction
March 29, 2018, © Leeham News: Boeing’s 787-9 has opened new ultra-long routes such as Qantas’ first flight from Perth in Australia to London Heathrow last weekend (a 7,900nm, 17-hours flight). The 787-9 has been the undisputed long-haul star under 300 seats, with Airbus A350-900ULR underbidding the Boeing 777-200LR’s fuel burn for over 300 seats ultra-long haul flying.
But the competition for below 300 seat ULR alternatives will change in two years. Airbus A330-800 is then available in its 251t version. It will fly longer than the 787-9, according to Airbus.
The range of 7,635nm given by Boeing for the 787-9 and 8,150nm by Airbus for the A330-800 is not using the same seating and fuel reserve rules. We use our performance model to weed out the differences, to make an apples-to-apples comparison of the 787-9 and A330-800 as ULR aircraft.
Summary:
- The choice between the 787-9 or A330-800 for Ultra Long-haul Routes (ULR) will depend on the passenger loads which can be expected.
- For thin routes, the A330-800 will be the cheaper aircraft to operate.
- It will also fly longer on thin routes, as its large tanks mean passenger capacity can be traded for more fuel further than for a 787-9.
- When the 787-9 can be filled, it’s the choice with the better seat-mile cost, as it should; it’s the larger aircraft, spreading fixed costs over more paying passengers.
Focus on NMA engines: all OEMs vying for Boeing’s approval
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Now open to all readers.
Introduction
March 22, 2018, © Leeham Co.: As Boeing enters the final stretch whether to launch the New Midrange Aircraft (NMA, aka 797) market focus should shift to the 
engines more than the airframe and even the market demand.
It all comes down to this: no engines, no plane.
Monday’s post outlined some of the issues to consider.
But there are larger implications as well.
Summary
- Market sources are tossing about various scenarios about the future GE Aviation and CFM.
- Rolls-Royce won’t have its Trent 1000 problems fixed until 2021 or 2022, at great cost.
- Pratt & Whitney won’t have its Geared Turbo Fan final PIP packages for its problems sorted out until around 2021.
- Resources—both financial and with engineering—are stretched now.
- Sequencing current engine problems, and in the case, GE’s GE9X, are a factor, in the eyes of some.
GE/CFM in “lockstep” with Boeing on NMA
David Joyce
March 22, 2018, © Leeham News: GE Aviation/CFM International are in “lockstep” with Boeing for development of an engine for the New Midrange Aircraft (NMA, or 797), the CEO of GE Aviation told a JP Morgan Aviation conference last week.
David Joyce acknowledged that there are technical issues and production delays for the new CFM LEAP 1A and 1B that power the Airbus A320neo and Boeing 737 MAX families respectively. Production is running up to six weeks late, but should be caught up by the end of this year, he said.
Technical issues, while affecting at least 100 engines, nevertheless are far less of an issue than those plaguing rival Pratt & Whitney’s Geared Turbo Fan.
Airbus launches the longest range widebody in the below 300 seat market
By Bjorn Fehrm
March 20, 2018, ©. Leeham News, Toulouse: Airbus launched the 251t version of the A330neo in Toulouse today. The new weight variant increases the range of the A330-800 and A330-900, making the A330-800 the longest range airliner in the 250- to 300-seat segment.
Airbus also presented an update on the progress of the A330neo program, now in the middle of flight tests.
Figure 1. A330neo changes from the A330ceo. Source: Airbus.
NMA focus needs to be on engines
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Now open to all readers
Introduction
March 19, 2018, © Leeham Co.: As the market awaits a decision by Boeing whether to launch the New Midrange Aircraft (NMA, or 797), focus has been on the aircraft’s definition and market demand.
It should be on the engines.
It doesn’t matter whether Boeing designs a fabulous airplane that’s the next best thing to sliced bread. What matters is whether the engines will be ready in time for Boeing’s suggested entry-into-service and if they are, whether they will be reliable out of the box.
The recent track record isn’t all that encouraging. Neither is Boeing’s preferred timing.
Summary
- CFM, GE, Pratt & Whitney and Rolls-Royce each had problems with their new engines. All continue.
- The Boeing NMA requires brand new engines, not derivatives.
- Engine development and certification within the Boeing preferred timeline is sporty at best.