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Energy efficiency of Wright model B

Published 05 November, 2020; last updated 10 December, 2020

The Wright model B:

  • flew around 0.10—0.21m/kJ
  • and moved mass at around 0.036 – 0.12 kg.m/J


The Wright Model B was a 1910 plane developed by the Wright Brothers.1


According to Wikipedia2:

  • Empty weight: 800 lb (363 kg)
  • Gross weight: 1,250 lb (567 kg)

We use the range 363—567 kg, since we do not know at what weight in that range the relevant speeds were measured.

Energy use per second

From Wikipedia, we have3:

  • Power: 35 horsepower = 26kW
  • Efficiency of use of energy from fuel: we could not find data on this, so use an estimate of 15%-30%, based on what we know about the energy efficiency of the Wright Flyer.

From these we can calculate:

Energy use per second
= power of engine x 1/efficiency in converting energy to engine power
= 26kJ/s / .15—26kJ/s / .30
= 86.6—173 kJ/s

Distance per second

Wikipedia gives us4:

  • Maximum speed: 45 mph (72 km/h, 39 kn)
  • Cruise speed: 40 mph (64 km/h, 35 kn)

We use the cruise speed, as it seems more likely to represent speed achieved with the energy usages reported.

Distance per Joule

We now have (from above):

  • speed = 40miles/h = 17.9m/s
  • energy use = 86.6—173 kJ/s

Thus, on average each second the plane flies 17.9m and uses 86.6—173 kJ, for 0.10—0.21m/kJ.

Mass.distance per Joule

We have:

  • Distance per kilojoule: 0.10—0.21m/kJ
  • Mass: 363—567kg

This gives us a range of 0.036 – 0.12 kg.m/J

Primary author: Ronny Fernandez


  1. “The Wright Model B was an early pusher biplane designed by the Wright brothers in the United States in 1910. It was the first of their designs to be built in quantity. “

    “Wright Model B.” In Wikipedia, September 16, 2020.

  2. “Wright Model B.” In Wikipedia, September 16, 2020.
  3. “Wright Model B.” In Wikipedia, September 16, 2020.
  4. “Wright Model B.” In Wikipedia, September 16, 2020.
power_of_evolution/evolution_engineering_comparison/energy_efficiency_of_wright_model_b.txt · Last modified: 2022/09/21 07:37 (external edit)