# Energy efficiency of Boeing 747-400

Updated Nov 5, 2020

The Boeing 747-400:

• covers around 0.0021m/kJ.
• and moves mass at around 0.39 – 0.83 kg.m/J

Contents

## Details

The Boeing 747-400 is a 1987 passenger plane.1

### Distance per Joule

The plane uses 10.77 kg/km of fuel on a medium haul flight.2 We do not know what type of fuel it uses, but typical values for aviation fuel are around 44MJ/kg.3 Thus to fly a kilometer, the plane needs 10.77 kg of fuel, which is 10.77 x 44 MJ = 474 MJ of fuel. This gives us 0.0021m/kJ.

### Mass.distance per Joule

According to Wikipedia, the 747’s ‘operating empty weight’ is 183,523 kg and its ‘maximum take-off weight’ is 396,893 kg.4 We use the range 183,523 kg—396,893 kg since we do not know at what weight in that range the relevant speeds were measured.

We have:

• Distance per kilojoule: 0.0021m/kJ
• Mass: 183,523 kg—396,893 kg

This gives us a range of 0.39 – 0.83 kg.m/J

Primary author: Ronny Fernandez

## Notes

1. “The Boeing 747-400 is a wide-body airliner produced by Boeing Commercial Airplanes, an advanced variant of the initial Boeing 747. The “Advanced Series 300” was announced at the September 1984 Farnborough Airshow, targeting a 10% cost reduction with more efficient engines and 1,000 nmi (1,850 km) more range. ”

“Boeing 747-400.” In Wikipedia, November 2, 2020. https://en.wikipedia.org/w/index.php?title=Boeing_747-400&oldid=986725646.

2. “Fuel Economy in Aircraft.” In Wikipedia, October 22, 2020. https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_aircraft&oldid=984919809.
3. “The net energy content for aviation fuels depends on their composition. Some typical values are:[15]

• BP Avgas 80, 44.65 MJ/kg, density at 15 °C is 690 kg/m3 (30.81 MJ/litre).
• Kerosene type BP Jet A-1, 43.15 MJ/kg, density at 15 °C is 804 kg/m3 (34.69 MJ/litre).
• Kerosene type BP Jet TS-1 (for lower temperatures), 43.2 MJ/kg, density at 15 °C is 787 kg/m3 (34.00 MJ/litre).”

“Aviation Fuel.” In Wikipedia, September 13, 2020. https://en.wikipedia.org/w/index.php?title=Aviation_fuel&oldid=978262126.

4. “Boeing 747-400.” In Wikipedia, November 2, 2020. https://en.wikipedia.org/w/index.php?title=Boeing_747-400&oldid=986725646.

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