Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- RTX Q1 2025 Earnings: GTF Talk Takes A Back Seat To Tariffs April 22, 2025
- Tariffs Tumult Takes Over GE Aerospace Q1 2025 Earnings Call April 22, 2025
- Boeing reports mixed results of latest employee survey, but middle management and officers remain key obstacles April 22, 2025
- Hopes for 1Q financial progress turns into bumpy ride for Boeing April 21, 2025
- Bjorn’s Corner: Air Transport’s route to 2050. Part 18. April 18, 2025
Bjorn’s Corner: Aircraft technology developments. Part 1.
By Bjorn Fehrm
February 24, 2023, ©. Leeham News: In the Sustainable Air Transport series we finished last week, we described new aircraft technologies developed to reduce Green House Gas (GHG) emissions.
There was one area we didn’t discuss, the progress on conventional technologies to reduce the fuel burn of an airliner.
We now start a series, digging deeper into what we can do with conventional technologies to reduce the fuel burned per passenger kilometer and, thus, GHG emissions.
Figure 1. Truss braced wing, a way to reduce aircraft drag. Source: Boeing.
The Airbus A220-500, a deep-dive analysis, Part 2
Subscription required
By Bjorn Fehrm
Jan. 23, 2023, © Leeham News: Following Thursday’s article about an up-and-coming Airbus A220-500, we now look at the operational cost for the A220-500 and compare it with the A320neo it should replace.
We put the data we discussed in Thursday’s article in our Aircraft Performance and Cost model, fly the aircraft on a typical single-aisle mission and look at the results.
Figure 1. A rendering of an A220-500 that takes 157 passengers. Source; Leeham Co.
Summary:
- The A220-500 would be a viable replacement for an A320neo.
- With the changes/improvements we discussed, it beats the A320neo on operational costs. The differences are not of the speculated level, however.
2023 outlook for Sustainable Aviation
Subscription required
By Bjorn Fehrm
Jan. 16, 2023, © Leeham News: In the years from 2015, Sustainable Aviation awareness has grown from “something interesting, but will it be needed?” to “how do we fix the environmental issues we have fast enough.” Scientists saw what happened 20 years ago, but the general public didn’t react until it affected everyday life.
The development of more Sustainable Aviation solutions has taken a similar route. Until 2015 the changes to morph aviation into a more sustainable path were a scientific discussion. At Le Bourget Air Show 2015, Airbus presented the E-Fan (Figure 1) that would cross the English Channel the following month. It started an intense debate about sustainable propulsion concepts for aircraft.
Eight years later, where are we today, and what will happen in 2023?
Figure 1. Airbus E-Fan at the 2015 Le Bourget Air Show. Source: Wikipedia.
Summary:
- The year will witness the “separation of the wheat from the chaff.” Viable concepts will prove themselves, and thin concepts, technically or funding-wise, will fail.
- We have a number of first flights from interesting projects. Several are in the “wheat” category.
Universal Hydrogen’s ATR72 Project
Subscription required
By Bjorn Fehrm
Dec. 22, 2022, © Leeham News: Last week, we wrote about Universal Hydrogen’s (UH2) plans to fly a hydrogen-fueled demonstrator aircraft in early 2023, followed by a certified conversion kit for an ATR72 airliner mid-decade.
The plans for the ATR72 hydrogen conversion are at an advanced state. As the first publication, we can describe the overall design and the technical details. The ATR72 implementation brings improvements in several areas compared with what’s been revealed before.
Figure 1. Hydrogen tank modules are loaded onto an ATR 72 using standard freight handling equipment. Source: Universal Hydrogen.
Summary:
- The target ATR72 conversion improves hydrogen capacity and handling compared to earlier concepts.
- The influence on the ATR seating capacity is reduced due to more efficient packaging on the aircraft.
Universal Hydrogen could be first with Hydrogen Airliner
Subscription required
By Scott Hamilton and Bjorn Fehrm
Dec. 15, 2022, © Leeham News: Universal Hydrogen (UH2) is perhaps weeks away from its first flight of a demonstrator that equips a De Havilland Canada Dash 8-300 with tanks of hydrogen and a fuel cell electric propulsion unit. The project shall prove the feasibility of hydrogen-fueled airliners.
The first flight’s date hasn’t been firmly set, but officials at UH2 told LNA it should be soon. Taxi tests of the aircraft will begin in the coming weeks. The flight will occur at Moses Lake in Central Washington State.
Universal Hydrogen supplies its hydrogen to the aircraft in prefilled barrel-sized tanks, called capsules, to avoid the lengthy and costly investment in storing and filling infrastructure at airports. The proof of concept is with a Dash 8, followed by a complete hydrogen conversion kit for an ATR-72 turboprop airliner.
Figure 1. Hydrogen tank pallets are loaded onto an ATR 72 by standard cargo loaders. Source: Universal Hydrogen.
Summary:
- The core business of Universal Hydrogen is the prefilled hydrogen tanks that load onto the aircraft in pallets.
- Universal Hydrogen builds the complete hydrogen fuel and propulsion system to prove and bootstrap the concept of hydrogen airliners.
Bjorn’s Corner: Sustainable Air Transport. Part 49P. eVTOL production costs. The deeper discussion.
Subscription required
By Bjorn Fehrm
December 9, 2022, ©. Leeham News: This is a complementary article to Part 49, eVTOL production costs. It discusses the typical production costs of a certified eVTOL when produced in large quantities.
eVTOLs will be produced under aeronautical production certification conditions, using aeronautical grade material and system. Our production cost model predicts such costs, including learning curve effects for each material type.
The Economics of the 767 and A330 at Seven and Eight abreast
Subscription Required
By Bjorn Fehrm
Introduction
Dec. 8, 2022, © Leeham News: In a previous article, we started speculating what an NMA type of aircraft would look like based on a Boeing 767 cross-section. An airliner’s cross-section decides the design of a large number of parts in an airplane.
In essence, a fuselage is a tube with a constant cross-section where the constant parts are repeated framewise to form the fuselage. It’s finished with a tapering forward cockpit and a rear tapering empennage.
We now look at what could have been a passenger version of an NMA that would have used the Boeing 767 cross-section with adaptations. To understand its economic impact, we make a comparison where we take a standard 767-300ER, then modify it to an NMA type fuselage and compare it to the competition in the size class, the A330-200 and -800.
As before, we do this by flying the world’s busiest long-haul route, London Heathrow, to New York JFK.
Summary
- An NMA based on an improved 767 fuselage cross-section would have been a very competitive airliner
- I would be the ideal replacement for the Boeing 757, 767, and 787-8.
Bjorn’s Corner: Sustainable Air Transport. Part 40. VTOL mission.
By Bjorn Fehrm.
October 7, 2022, ©. Leeham News: Last week, we discussed the reality of mass fractions for certified aircraft. There is an abundance of statistics on projects that have gone through the arduous development and certification phase, which always turns out heavier than projected.
Using such statistics, we have a base from which to fly a typical hover and cruise eVTOL design and see what we get in terms of energy consumption and range.
Figure 1. The Vertical Aerospace VX4 in an early rendering with similar looks to the eVTOL we discuss. Source: Vertical Aerospace.
Bjorn’s Corner: Sustainable Air Transport. Part 36. Battery Management.
By Bjorn Fehrm
September 9, 2022, ©. Leeham News: Over the last weeks, we have discussed the cells that make up the battery system for an eVTOL.
The battery system has 10,000 cells or more. All these must, on an individual level, be managed to ensure they operate inside their allowed values. The Battery Management System, BMS, has this responsibility. It’s one of the most critical safety systems in an eVTOL.
Figure 1. The Battery Management System and battery packs from EP Systems. Source: EP Systems.
Bjorn’s Corner: Sustainable Air Transport. Part 33P. eVTOL batteries. The deeper discussion.
Subscription required
August 19, 2022, ©. Leeham News: This is a complementary article to Part 33, eVTOL batteries. It discusses the trickiest system on an eVTOL, the battery system.
While Lithium Ion batteries have come a long way since the electric flight ideas took off in 2015, the battery system is still the biggest challenge for eVTOL designers, not only for total energy content but for a range of parameters.