Bjorn’s Corner: The challenges of airliner development. Part 12. The Prelaunch Phase.

By Bjorn Fehrm, Henry Tam, and Andrew Telesca.

July 16, 2021, ©. Leeham News: Last week, we showed the first cut of an overall Program Plan for our 19 seat airliner project.

Now we discuss the Prelaunch Phase activities in more detail, including what type of knowledge, tools and resources we need to get on board for the project.

Figure 1. The Viking Twin-Otter utility-oriented unpressurized 19 seater. Source: Wikipedia.

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The true cost of Electric Aircraft. Part 2.

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By Bjorn Fehrm


July 8, 2021, © Leeham News: Last week, we looked at the cost of running an electric 19 seat airliner based on energy stored in batteries. We found the energy costs were lower than for the equivalent turboprop aircraft, but when we add the maintenance costs for the batteries, the operating costs were higher than today’s 19 seat commuter.

This was under the assumption that the battery aircraft had the same energy consumption as today’s aircraft. We now run this check. The result is eye-opening.

Figure 1. Heart Aerospace ES-19 battery-based airliner. Source: Heart Aerospace.

  • Battery based aircraft weigh significantly more than jet fuel based ones. It increases their energy consumption.
  • Last week’s findings were conditioned on the same energy consumption. This week’s analysis proofs this is not a valid assumption.

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Bjorn’s Corner: The challenges of hydrogen. Part 33. Wrap-up: The Eco-system

By Bjorn Fehrm

April 16, 2021, ©. Leeham News: Last week, we wrapped up the operational part of sustainable air transport using hydrogen as an energy source.

Now we look at where we are with the all-important Eco-system. It has many moving parts and risks a chicken and egg stalemate.Figure 1. The prospective conversion of the European gas pipeline network to hydrogen. Source: EU.

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Pontifications: Recovery plans from the pandemic at ATR, De Havilland

By Scott Hamilton

March 29, 2021, © Leeham News: Aviation stakeholders’ attention understandably focuses on Airbus and Boeing as the industry works its way through the COVID-19 pandemic. Embraer gets less attention than the Big Two.

But two other OEMs must be considered as well: ATR and De Havilland Canada.

Outside of China and Russia, whose home-grown industries sell only to these markets, ATR and DHC are the only manufacturers of turboprops in the 50-90 seat sectors.

LNA revealed on Jan. 12 that DHC would suspend Dash 8-400 production after the small backlog rolled off the assembly line. The privately held company delivered 11 airplanes last year due to the pandemic.

About 900 aging regional turboprop aircraft need to be replaced in the coming years.

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Bjorn’s Corner: The challenges of hydrogen. Part 28. Airbus priorities

March 12, 2021, ©. Leeham News: I had the chance to talk about Sustainable Air Transport with Airbus VP Zero Emission Aircraft, Glenn Llewellyn, in the week.

The discussion centered around Airbus’ overall direction and the targets with their ZEROe project.

Figure 1. Airbus ZEROe airliner concepts. Source: Airbus.

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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.

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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.

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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.

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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?

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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.

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