Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- Boeing’s 737 North Line and the Everett factory: in transition now June 9, 2025
- Bjorn’s Corner: Air Transport’s route to 2050. Part 25. June 6, 2025
- New RISE powerplant benefits from decades of GE research and development June 5, 2025
- Engine makers emphasizing durability, reliability June 4, 2025
- Boeing CEO: Lessons learned are key to certification of 737-7/10 and 777X June 2, 2025
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.
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?
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.
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.
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.
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.
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.
Retrospective: 2011 pros and cons of composite airplanes as Boeing, Airbus look to next 20 years
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By Scott Hamilton
What will the Future Small Airplane look like? Composites, metal, or a combination? Concept Credit: Leeham News.
Aug. 29, 2022, ©Leeham News: Airbus and Qatar Airways are in a nasty court battle over composite degradation on the A350. Lightning strike protection is a major concern in the Qatar lawsuit. Paint begins to strip off composite materials on the A350 and Boeing 787. Building composite airplanes is expensive.
Composites have been on airplanes since the days of the Boeing 727 when the wing-to-body fairings were made of composites. Airbus put composite vertical fins on the A310 and A300-600R. Private airplanes used composites.
But it was the Boeing 787 that became a ground-breaking airliner with its composite wings and composite fuselage. Boeing’s launch of the 787 in December 2003 was what would later be described as a moonshot. It was the first “all” composite airplane. (About 52% by weight was composite.)
It was the first “all-electric” aircraft, meaning all systems were powered by electric energy. Boeing intended that this would be a “snap-together” airplane. Fuselage sections were to be “stuffed” when delivered to the final assembly line in Everett (WA) and “snapped” together, like a prefabricated house. Outsourcing to industrial partners was taken to unprecedented levels at Boeing. (Airbus already largely practiced this for its aircraft.)
Engine Development. Part 2. The early jet engines.
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By Bjorn Fehrm
Introduction
August 25, 2022, © Leeham News: Last week, we started a series about jet engine development for our air transport aircraft. The jet engine came to replace the piston and gas turbine propeller engines when airplanes sought higher cruising speeds.
In the second part of the series, we look at why the jet engines were developed and their advantages and disadvantages compared to what they replaced.
De Havilland Comet, the first jet airliner. Source; Wikipedia.
Summary
- When the propeller engine came to its speed limits, the straight jet engine was the answer.
- While it helped with speed, it created other problems.