Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- Boeing CEO: Lessons learned are key to certification of 737-7/10 and 777X June 2, 2025
- Digital twin is a key to JetZero’s hopes for Blended Wing Body entry June 2, 2025
- Bjorn’s Corner: Air Transport’s route to 2050. Part 24. May 30, 2025
- Does an A220-500 need a new wing and engines? Part 3. May 29, 2025
- Boeing’s future depends on FAA approvals May 26, 2025
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.
Engine Development, Part 1: Launch to Entry into Service
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By Vincent Valery
Introduction
Pratt & Whitney Geared Turbofan
Aug 18, 2022, © Leeham News: LNA analyzed the evolution of commercial aircraft development timelines last month. The time between a program launch and entry into service significantly increased over time, including for derivatives.
The increase in development time is primarily the result of more complex and safer airplanes. Introducing new materials, notably a more extensive use of composites, also explain longer development timelines.
LNA now starts a new series on the topic of commercial aircraft jet engines. The goal is to go through significant innovations from the beginning of the jet age.
This first article analyses whether engine development time between launch and entry into service increased significantly over time.
Summary
- Military development led to the first commercial jet engines;
- The divergence between military and commercial programs;
- Pushing the envelope of the same fundamental engine architecture;
- Harder to identify development timeline evolution.
P&W, Collins Aerospace launch hybrid-electric demonstrator
By Scott Hamilton
July 18, 2022 (BST), © Leeham News: Pratt & Whitney and sister company Collins Aerospace announced the launch of a hybrid-electric technology demonstrator, it was announced today at the Farnborough Air Show. This program is for future advanced air mobility vehicles.
Collins and Pratt & Whitney Canada, the turboprop engine unit, also announced the completion of the preliminary design of a 1MW motor for the demonstrator. A De Havilland Canada Dash 8-100 will be the platform for the commercial hybrid-electric application.
Pontifications: Next new mainline jet likely will be conventionally powered
By Scott Hamilton
May 9, 2022, © Leeham News: Pratt & Whitney thinks a hybrid-electric propulsion system might be ready for installation on the next new airplane from Boeing or Airbus by 2031. But more likely is that the new airplane, whatever design it is, will more likely be powered by a conventional engine that is capable of running on 100% Sustainable Aviation Fuel (SAF).
Graham Webb, the chief sustainability officer at Pratt & Whitney, said PW is “obviously investing in our Geared TurboFan. That’s our bread and butter. We are working to infuse a large number of technologies, including ceramic matrix composites, and aerodynamic improvements to the turbines and the compressor. We’re working on improving the cooling optimization and sealing, and the traditional core efficiency suite of technologies to enable us to get to the higher overall temperatures we need for the next generation cycles.
“We’ve already completed a suite of work with the FAA and our clean aviation program that enabled us to expand the bypass ratio of our Geared TurboFan engine further from where we are till now. We’re going to use that technology to grow the engine. We’ll put a different fan-drive gear system technology as a result of that expansion. That’s kind of like the traditional engine efficiency piece,” Webb said at the Aviation Week’s MRO Americas event in Dallas. LNA spoke with Webb on the sidelines of the huge event, attended by more than 13,000 people.
Under the FAA CLEEN Phase I program, PW developed ultra-high bypass ratio technologies beyond the current 12:1 present in today’s GTF engines. These technologies are ready for deployment for a future new aircraft. The specific bypass ratio of this new engine will be optimized to each installation on the new airframe configurations being developed by the airframers, a spokesperson added.
Pontifications: The soup du jour
March 14, 2022, © Leeham News: You might call it the soup du jour.
By Scott Hamilton
EcoAviation is all over the place at aviation conferences these days. It was a key topic at last October’s Annual General Meeting of the International Air Transport Association (IATA). Likewise at last month’s annual conference of the Pacific Northwest Aerospace Alliance (PNAA). EcoAviation also was an element of the Speed News conference in Los Angeles early this month and at another event the following week. Investor Day events now routinely include ecoAviation discussion.
This is all well and good, but at last, some key members of the industry are putting caution and realism to the pie-in-the-sky stuff that is sucking up investment like the Dot Com era a few decades ago. Only a few ideas and technologies will be successful.
HOTR: Collins Aerospace sustainability
Feb. 22, 2022, © Leeham News: The headlines and debate over ecoAviation focus on the airframe and engine manufacturers, for good reason. But the aerospace supply chain is mindful of its ESG (Environmental, Social, and Governance) issues as well.
Pratt & Whitney makes the engines that emit emissions and burn fuel. It works to reduce fuel burn and emissions. PW also is exploring electric, hybrid and hydrogen alternatives. Sister company Collins Aerospace works to find solutions to reduce emissions in other areas.
“We play a big role in sustainability,” says LeAnn Ridgeway, Vice President, Sustainability. Collins purchased FlightAware, which is perhaps best know for flight tracking in competition with FlightRadar24. But FlightAware provides route planning and ADS-B services, among others.
For next new airplane, Pratt appears to trail CFM for next new engine
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By Scott Hamilton
Feb. 21, 2022, © Leeham News: As Boeing ponders whether to launch a new airplane program and industry consensus seems to be that this must happen in 2023 or 2024, Pratt & Whitney seems to face a dilemma.
Pratt & Whitney Geared Turbo Fan engine. Credit: Pratt & Whitney.
Convinced that the Geared Turbo Fan technology is the path to future engines, nevertheless, public statements indicate that by 2035, the GTF in the conventional form will fall short of the Open Fan being developed jointly by GE Aviation and Safran. GE and Safran are 50-50 partners in CFM International, which will sell the engine.
Rick Deurloo, the chief commercial officer for PW, told LNA last October that by 2031 (at the time, 10 years in the future), the GTF will have a 10% improvement in fuel burn and emissions compared with today’s GTF. PW will have a 1% improvement by 2024.
GE’s Travis Harper, who is the program manager for the Open Fan “RISE” engine under development, told LNA earlier this month that the RISE will reduce fuel consumption and emissions by 20% and be ready for entry into service by 2035.
If the goals outlined by Deurloo and Harper are taken at face value and achieved, this means the GTF will be up to 10% short of CFM’s engine ready for EIS four years later.
This was the question LNA put to other representatives of GE and PW at the Pacific Northwest Aerospace Alliance conference Feb. 10.
P&W, Embraer pause E175-E2 engine; MTU writes off investment, sees no revenue in future for SpaceJet engine
By Scott Hamilton
Exclusive: Dec. 21, 2021, © Leeham News: Pratt & Whitney and Embraer agreed to suspend further development and production of the PW1700G for three years, LNA learned.
Another airplane without an engine.
PW and Embraer did not respond to inquiries. Separately, the aerospace company MTU reported earlier this year that it wrote off its entire investment in the PW1200G and expects no revenue from the program in the future.
Update: P&W provided this statement Dec. 22: “As already informed to the market, Embraer and P&W are evaluating E175-E2 program timing given market conditions and scope clause.“
The engine was developed for the Mitsubishi MRJ. Development of the MRJ90 and follow-on MRJ70 were refined to the M100 SpaceJet when analysis concluded the MRJ90 wasn’t economically competitive with the E190-E2. A myriad of technical flaws also was discovered in the flight test vehicles that rendered the original design uncertifiable.
Mitsubishi Heavy Industries indefinitely suspended the SpaceJet program in 2020. Embraer rescheduled the entry-into-service of the E175-E2 from 2021 twice, now targeting EIS for 2025. This depends on US pilot unions relaxing an airplane weight restriction in the labor contracts. The E175-E2 weight exceeds that allowed in the contracts.
Engine OEMs pushing ahead for next airplane, even as Boeing pauses
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By Scott Hamilton
Nov. 1, 2021, © Leeham News: David Calhoun may not be anywhere near ready to launch the Next Boeing Airplane (NBA), but the engine makers are actively researching and developing engines to hang of whatever that NBA will be.
Calhoun, the CEO of Boeing, repeatedly said the NBA will be more about reducing production costs through advanced design and production methods. For some time, Calhoun said the next engines available on the assumed timeline—to about 2030—will have only 10% better economics than today’s engines.
And 10% isn’t enough for the airlines or the commensurate reduction in emissions.
CFM/GE Aviation/Safran are developing an “open fan” engine that will reduce fuel burn and emissions by 20%. A target date for entry into service is in the 2030 decade. The open fan builds on R&D of open rotors that have been underway since the era of the Boeing 727 and McDonnell Douglas MD-80.
Pratt & Whitney sees an evolution of its Geared Turbofan engine. The GTF was under development for 20 years before an operating engine made it onto the Bombardier C Series (now the Airbus 220), the Airbus A320, and United Aircraft MC-21. The GTF also was selected for the Mitsubishi MRJ90, which launched the GTF program. However, Mitsubishi pulled the plug on the MRJ/SpaceJet program last year. PW remains committed to the GTF for future engines.
Rolls-Royce is developing the Ultra Fan and Advanced engines. GE’s Open Fan and RR’s engines adopt geared turbofan technology pioneered by PW but add new technology.
LNA takes a look at the new engines for the NBA or any other competing airplane in a series of articles.
IATA AGM: Airplanes, engines SAF capable coming; feedstock lags by years
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By Scott Hamilton
Introduction
Oct. 4, 2021, © Leeham News: Engine and airframe makers are well on their way to becoming fully capable of using Sustainable Aviation Fuel (SAF). But the industries providing SAF are way behind in meeting the potential demand.
Rick Deurloo of Pratt & Whitney
Rick Deurloo. Sr. VP & Chief Commercial Officer at Pratt & Whitney said one major US airline would use all currently available SAF in one day.
“The challenge will be the feedstock. How do we grow that technology or grow that ability to provide the feedstock so when we do have 100% SAF-capable aircraft and engines, we have the energy to go with it?” Deurloo said in an interview with LNA at the IATA AGM this week in Boston.
Airlines around the world are partnering with different companies to develop this technology, he said.
PW is already 50% capable and has a “clear path” to getting 100% capable within two years. But there is not enough feedstock in the world today do fill the 50% capability.