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Bjorn Fehrm

Bjorn Fehrm

@bjorn-fehrm · 8 positions · On ppll ↗

Aeronautical engineer, former fighter pilot and airline executive, now an analyst at Leeham Company writing the weekly Bjorn's Corner on aircraft economics and design. He works from an aircraft performance model and has spent years checking the arithmetic of electric, hybrid and hydrogen aviation projects against it.

Bjorn Fehrm did not write this page.

We collected these quotes from things they published elsewhere, and every quote links to where it was said. They have no account here and have not endorsed this site. Quotes are word for word; the short line under each one is our own restatement, not their wording. Their own site. Is this you? Claim it or ask us to remove it. Or tell us what is wrong here.

2 of Bjorn Fehrm's claims fit 2 mental models. Most often: Bottlenecks, First principles.

Models we see in what they say

Our reading: their claim applies the idea without naming it. The claim is theirs; filing it here is ours.

Bottlenecks

A system moves only as fast as its narrowest point; speed up anything else and nothing changes.

Used by 89 others

Sustainable aviation fuel cannot be scaled to the size of the fleet, because its feedstock competes with growing food.

  1. Bjorn Fehrm Aeronautical engineer, former fighter pilot and airline… There won’t be enough of it for the 25,000 planes flying each day, the feedstock will compete with food production. Bjorn’s Corner: The challenges of hydrogen. Part 31. Wrap-up: Where we standleehamnews.com · 2 Apr 2021All korrents from this piece
    Their wordsThere won’t be enough of it for the 25,000 planes flying each day, the feedstock will compete with food production.

    ↗Bjorn’s Corner: The challenges of hydrogen. Part 31. Wrap-up: Where we standleehamnews.com

    2 Apr 2021

First principles

Reason up from what is known to be true, not from what is usually done or said.

Used by 20 others

Battery-electric airliners do not work even on optimistic assumptions, and the arithmetic said so before anyone built one.

  1. Bjorn Fehrm Aeronautical engineer, former fighter pilot and airline… Having done the sums before hitting the keys, I was a skeptic. It just didn’t work, even with optimistic assumptions around the parameters for the aircraft and its batteries. Bjorn’s Corner: The challenges of hydrogen. Part 31. Wrap-up: Where we standleehamnews.com · 2 Apr 2021All korrents from this piece
    Their wordsHaving done the sums before hitting the keys, I was a skeptic. It just didn’t work, even with optimistic assumptions around the parameters for the aircraft and its batteries.

    ↗Bjorn’s Corner: The challenges of hydrogen. Part 31. Wrap-up: Where we standleehamnews.com

    2 Apr 2021