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 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
- Updated, May 29, 2025: Department of Justice, Boeing OK to Non-Prosecution Agreement May 23, 2025
- Bjorn’s Corner: Air Transport’s route to 2050. Part 23. May 23, 2025
Bjorn’s Corner: The challenges of hydrogen. Part 25. Auxiliary power
By Bjorn Fehrm
February 19, 2021, ©. Leeham News: Last week we discussed hydrogen aircraft propulsion and found a shaft power producing gas turbine was considerably more weight-efficient than a fuel cell powering an electric motor. Both had the same 55% shaft power efficiency.
Will a gas turbine APU burning H2 be the best choice for auxiliary power as well?
Figure 1. The Honeywell 131-9 APU for the Airbus A320. Source: Honeywell.
Bjorn’s Corner: The challenges of hydrogen. Part 22. Hydrogen fuel cells
By Bjorn Fehrm
January 29, 2021, ©. Leeham News: Over the last weeks, we looked at Center of Gravity (CG) problems with rear fuselage liquid hydrogen tanks as used in Airbus’ ZEROe turbofan airliner concept. We can conclude that the CG shift is manageable for a short-range aircraft (range below 2,000nm).
Now we spend the next Corners diving into hydrogen fuel cell technology and how it can benefit a hydrogen-fueled airliner.
Figure 1, The principle of a hydrogen fuel cell. Source: Airbus.
Bjorn’s Corner: The challenges of hydrogen. Part 17. Hydrogen airliner program
By Bjorn Fehrm
December 11, 2020, ©. Leeham News: We use this Corner to define the time table for our hydrogen airliner program and for what areas we need to conduct risk-reducing research before we embark on an actual design.
As we said in last week’s Corner, we aim to develop a hydrogen airliner for the heart of the domestic market after the COVID-19 Pandemic. It’s a 160 to 180 seat single-aisle turbofan driven airliner, using liquid hydrogen as the fuel.
Figure 1. Airbus ZEROe hydrogen-fueled airliner concepts. Source: Airbus.
Bjorn’s Corner: The challenges of Hydrogen. Part 12. Safety
By Bjorn Fehrm
October 23, 2020, ©. Leeham News: In our series on Hydrogen as an energy store for airliners we look deeper at the safety of a hydrogen airliner.
Do the safety rules for the aircraft or the airport need to be written new or can the existing ones be used with changes?
Hydrogen, electric and hybrid alternatives not here yet
By Scott Hamilton
Sept. 25, 2020, © Leeham News: Commercial aviation has had 70 years to use jet fuel safely. It’s unclear how long it will take to reach the same level of safety with hydrogen, say Boeing.
In a briefing Tuesday, the day after Airbus revealed its hydrogen powered concepts for three potential airliners, the vice president and general manager of product development expressed caution about hydrogen as a fuel source.
Bjorn’s Corner: The challenges of Hydrogen. Part 9. Hydrogen Gas Turbines
September 18, 2020, ©. Leeham News: In our series on hydrogen as an energy store for airliners we analyze the conversion of the present Turbofan and Turboprop airliner engines to hydrogen as fuel instead of carbon-based fuels.
We know it’s possible as the world’s first jet engine from 1937 ran on hydrogen, Figure 1. But what are the problems and how good are the hydrogen-fueled engines in efficiency and emissions?
Figure 1. The world’s first jet engine, Hans von Ohain’s He S-1. The engine’s aerodynamics is pictured below the cut-through. Note the skewed hydrogen injector at c. Source: Wikipedia.
Bjorn’s Corner: Why e in ePlane shall stand for environment, Part 13. Serial Hybrid.
March 13, 2020, ©. Leeham News: In this week’s Corner, we address an often forgotten aspect of Electric and Electric-Hybrid aircraft design.
The battery as an energy source, as the only or assisting source, has the same weight during the whole flight. A fuel (alternate, fossil, or hydrogen) consumes during the flight. You gradually fly a lighter aircraft. Let’s see how this affects the aircraft’s efficiency.
Figure 1. Embraer’s E175-E2, a latest-generation 88 seater jet used for our example. Source: Embraer.
Bjorn’s Corner: Why e in ePlane shall stand for environment, Part 12. Battery risks.
March 6, 2020, ©. Leeham News: We use this week’s Corner to discuss the safety hazards a change to an Electric or Hybrid-Electric airliner introduces.
The trigger is two battery fires in six weeks for the electric aircraft prototypes which are now flooding the market.
Figure 1. Eviation’s Alice battery-driven prototype. Source: Eviation
Bjorn’s Corner: Why e in ePlane shall stand for environment, Part 7. Efficiency of cars versus airliners.
January 31, 2020, ©. Leeham News: We now look at ways to increase the fuel efficiency of our airliner and by it, improve the CO2 situation for our environment.
Let’s start with understanding where we are with the efficiency of our present air transport system. To get a feel for where we are we will compare it to our road transport system.
Figure 1. A principal view of a two-spool airliner turbofan. Source: Wikipedia.
Bjorn’s Corner: Why e in ePlane shall stand for environment. Part 1. Hype versus reality.
December 13, 2019, ©. Leeham News: The first all-electric commercial aircraft, a Harbor Air DHC-2 Beaver, flew over the Fraser River near Vancouver in the week (Figure 1). It was powered by a magniX electric engine fed with energy from batteries.
Despite this progress, this Corner series is about why the e in our future ePlanes should stand for environment and not electric.
Figure 1. Harbour Air seaplane flying with a magniX electric engine feed by batteries. Source: magniX.