Engine Development. Part 8. Throttle push or not?

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By Bjorn Fehrm

Introduction

October 6, 2022, © Leeham News: The early years of 2000 saw new engine programs launched for the new Boeing 787 Dreamliner and Airbus response, the A350.

Substantial differences in the life of these aircraft programs made the engine programs develop differently. It was about throttle push or not.

Summary
  • The Dreamliner engines changed as the 787 programs went through many stages.
  • The Airbus A350 program was a standard program in comparison.

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Achieving net zero carbon is a promise you can keep: P&W’s Webb

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By Scott Hamilton

Sept. 26, 2022, © Leeham News: The International Civil Aviation Organization (ICAO) is nearing the next step in support of dramatically cutting emissions by airlines and the aviation industry.

Graham Webb

“ICAO has been working for about the last three years on something called a long-term aspirational goal (L-TAG). That’s regarding a study that was conducted by a number of their scientists to determine if it is feasible for the aviation industry to reduce its carbon emissions specifically, to achieve a net zero standard. That’s what for a long-term aspirational goal is,” said Graham Webb, Chief Sustainability Officer for Pratt & Whitney. “At this point, the study has been completed and has been reviewed by 93 member states. It would appear that the initial motion of the language that is going to be put forward will pass.”

ICAO previously adopted the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA). L-TAG is the next step, Webb said in an interview this month with LNA.

“Once that is in place, it will enable ICAO, much as it already is done with CORSIA, to establish policies that would then be enforced by all its member states in a common, in a related way as opposed to the concern that many people have had, where you would see a patchwork. You would see some countries, such as the United States, providing incentives through vendors’ tax credits. You would see Europe in the form of mandates and taxes. They have this Emissions Trading Scheme that they’ve been putting forward and running through the Parliament. The overall objective is to have this singular global aviation industry, regulatory body, ICAO, that would then set the guidelines for the industry.”

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Engine Development. Part 6. High Bypass goes mainstream

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By Bjorn Fehrm

Introduction

September 22, 2022, © Leeham News: With the introduction of the High Bypass engine for the Boeing 747, Douglas DC-10, and Lockheed Tristar, it was obvious Pratt & Whitney’s low bypass engines on the Boeing 707, 727, 737, and Douglas DC-8, -9 should be attacked with a new High Bypass engine in this thrust class.

French Snecma and GE teamed up to break Pratt & Whitney’s monopoly of the jet engine market outside the widebodies. The CFM56 was born.

Figure 1. The Boeing 737-300, the breakthrough for the CFM56 engine. Source; Wikipedia.

Summary
  • With an exclusive fit on the Boeing 737 and a 10-year introduction advantage on the A320, the CFM56 has dominated over the competing IAE V2500.
  • The CFM56 is the world’s most produced jet engine, with over 32,000 engines produced to date.

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The Airbus and Boeing market outlooks, Part 2

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By Vincent Valery

Introduction  

Credit: Leeham Company LLC

Sept.  19, 2022, © Leeham News: In the first article last week, we focused on the differences in market outlook assumptions between Airbus and Boeing. Despite similar levels of passenger single-aisle and twin-aisle deliveries envisioned over the next two decades, there were significant differences in the underlying assumptions.

We now focus on whether there is enough production capacity to meet the envisioned aircraft demand over the next two decades.

Summary
  • Outlining the delivery forecast assumptions;
  • Converting deliveries into production rates;
  • Estimating production capacity;
  • Is Boeing implying something?

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Engine Development. Part 5. The Turbofans go High Bypass

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By Bjorn Fehrm

Introduction

September 15, 2022, © Leeham News: Last week, we looked at how Pratt & Whitney’s JT8D turbofan came to dominate short-haul airliners while the JT3D had the long-range market.

The introduction of the widebody jets in the 1970s with Boeing 747, Douglas DC-10, and Lockheed Tristar brought GE and Rolls-Royce into the market. It was the start of the high bypass turbofans.

Figure 1. The roll-out of the Boeing 747-100 on September 30, 1968.

Summary
  • The military TF39 for Lockheed C-5 Galaxy military transport set the benchmark for the new generation of high bypass turbofans with its 8-to-1 bypass ratio.
  • Pratt & Whitney, GE, and Rolls-Royce developed civil engines along the lines of the TF39 for the new generation widebodies.

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The Airbus and Boeing market outlooks, Part 1

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By Vincent Valery

Introduction  

Sept.  12, 2022, © Leeham News: Airbus and Boeing published their updated 2022-2041 commercial aircraft outlooks ahead of the July Farnborough Air Show. Unsurprisingly, both OEMs saw robust demand for the next two decades despite recent economic headwinds that lowered long-term fleet growth forecasts.

Credit: Leeham Company LLC, 2022

Airbus and Boeing see a market for delivering 38,600 and 38,110 single-aisle and twin-aisle passenger aircraft over the period. A 1.3% difference over 20 years is well below the margin of error of such long-term forecasts.

However, despite such minor overall differences in long-term delivery forecasts, both OEMs use different assumptions to come up with those numbers.

Also, the recent challenges with increasing production rates on single-aisle aircraft raise the question of whether there is enough capacity to meet the optimistic demand outlook.

The first part of this two-article series highlights the main assumption differences between the Airbus and Boeing market outlooks. The second will translate those assumptions into production rates and assess whether OEMs can meet that demand, notably over the next 10 years.

We will focus on the single-aisle (100 passengers and above) and twin-aisle passenger markets.

Summary
  • One OEM is more optimistic about fleet growth;
  • Another on replacement rates;
  • A (maybe not) surprising up-gauging assumption for one OEM;
  • Higher growth rates than meet the eye.

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Engine Development. Part 4. Turbofans go mainstream.

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By Bjorn Fehrm

Introduction

September 8, 2022, © Leeham News: Last week, we analyzed the change from turbojets to turbofans for civil air transport. The jet engine was developed for high-speed military fighters and was not ideal for subsonic airliner use.

We also dwelled on why the three major engine OEMs came to different solutions for the first-generation turbofans. Now we look at the engine that made turbofans mainstream, the Pratt & Whitney JT8.

Figure 1. The Boeing 727-100 with Pratt & Whitney JT8 engines. Source: Wikipedia.

Summary

  • The JT8 competed with the more developed Rolls-Royce Spey to engine the first US domestic jet airliner, the Boeing 727.
  • After it captured the Boeing 727, it went on to engine all US short and median haul jets of the 1960s.

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ICAO report outlines steps to reduce aviation’s carbon output

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By BRYAN CORLISS

Sept. 5, 2022, © Leeham News: Saying the climate crisis now is at “Code Red for Humanity,” the UN-sponsored International Civil Aviation Organization is calling on nations and companies to increase their investments toward techniques and technologies that can reduce aviation’s climate impact.

It won’t be easy, ICAO said in its Environmental Report 2022, which was released in July. 

The aviation industry will be one of the hardest to ween off carbon-based forms of energy, a recent report concluded. 

“Scaling the production of sustainable aviation fuels (SAF) and other energy sources requires substantial investment and financial support from both fuel suppliers and governments on top of what would be needed for associated infrastructural changes,” the report said. “This is particularly important, considering that the drop-in fuels have the largest potential to reduce the overall emission from international aviation by 2050.”
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Bjorn’s Corner: Sustainable Air Transport. Part 35P. Lilium battery cells. The deeper discussion.

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September 2, 2022, ©. Leeham News: This is a complementary article to Part 35, Lilium battery cells. It discusses the requirement the Lilium jet principle puts on its battery cells and how this is solved, both with a modified cell type and with some operational adaptations.

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Engine Development. Part 3. The early turbofans.

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By Bjorn Fehrm

Introduction

September 1, 2022, © Leeham News: Last week, we looked at the motivation to change from propeller engines to jet engines as higher cruising speeds were sought for airliners.

We learned the straight jet engine, while good for military jets, wasn’t well suited for civil airliners. It was noisy and fuel-thirsty. It was why the subsequent engine development, the turbofan, was quickly accepted by the airlines.

Figure 1. A Boeing 707 with Pratt & Whitney JT3D turbofan engines. Source: Wikipedia.

Summary
  • The first turbofans from Rolls-Royce, Pratt & Whitney, and GE had different designs.
  • The advantages of the turbofan over the straight jet were quickly recognized. The turbofan has been the choice for airliners since the late 1950s.

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