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The Concorde burnt five times more fuel per passenger mile than the 747. A huge contributor must have been the immense empty weight per seat, three times that of the B747.

B747-300 Concorde
Empty Weight 174,000 kg 78,700 kg
Passengers 400–660 92–128
EW/Passenger 263–435 kg 615–855 kg

This weight excess is distributed among the slender fuselage, thin wings, long landing gear, big engines, and (possibly) material constraints.

But how much of the weight increase comes from each of these components, and why? I am looking for a comparison with the weight breakdown of a conventional jetliner

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The Concorde mainly transported fuel across the Atlantic so that enough was available to land safely. Passengers were just an extra on top. Also, being first-class only, it held fewer passengers than what low budget airlines have taken to cramming into their planes lately.

To look at the structure relative to passengers is a bit misleading. Let's look at the fuel load and the mass fraction of empty weight relative to MTOW instead:

747-100 Concorde
MTOW 333.4 tons 186.88 tons
Empty mass 162.5 tons 78.9 tons
Fuel 183,380 liters 119,800 liters
Fuel to empty mass 1.1285 L/kg 1.5146 L/kg
Mass fraction of empty to MTOW 48.74% 42.22%

If you compare passengers plus fuel to the empty mass of each airplane, the Concorde actually comes out well ahead of the 747 and looks like a prize of lightweight design. Having structurally efficient delta wings helped and should explain most of the difference.

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  • $\begingroup$ Also, could you give that fuel fail in numbers? $\endgroup$
    – Abdullah is not an Amalekite
    Commented Mar 7, 2021 at 9:00
  • $\begingroup$ @Abdullah What is a fuel fail? $\endgroup$
    – Peter Kämpf
    Commented Mar 7, 2021 at 9:01
  • $\begingroup$ Fuel fail is a portmanteau of "fuel" and "epic fail". It is used to describe a situation where a passenger aircraft becomes a fuel tanker, and the customer of this fuel tanker is the same aircraft, and this fuel is needed to ensure that the aircraft lands in such a way that leftover fuel is not spilled. $\endgroup$
    – Abdullah is not an Amalekite
    Commented Mar 7, 2021 at 9:16
  • $\begingroup$ I was referring to that thing about transporting fuel over the ocean just to land. Sorry for the lazy wording $\endgroup$
    – Abdullah is not an Amalekite
    Commented Mar 7, 2021 at 9:19
  • $\begingroup$ @Abdullah: Carrying fuel for cost difference reason is also known as tankering. $\endgroup$
    – mins
    Commented Apr 1, 2021 at 21:54
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A major factor would seem to be just the square-cube law. The material needed to make a tin can increases as the square of its diameter, but the amount of stuff you can put in it - whether sardines or humans - increases as the cube. Doing the same calculation for e.g. a Citation X (12 passengers) gives about 820 kg empty weight per passenger. Then the Concorde has to be stronger and have more fuel tankage to cope with supersonic flight...

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    $\begingroup$ The square–cube law isn't probably it. The slender MD-80 is only 253 kg/pax (similar to B747) for the typical seating (similar to Concorde). Then again it has two weak engines and tiny wings compared to Concorde. $\endgroup$
    – user14897
    Commented Mar 6, 2021 at 18:37
  • $\begingroup$ @ymb1 Put four afterburning engines on an MD80, plus fuel to feed them pushing the plane to supersonic speeds, plus wings large enough to hold all that fuel, and weight will probably approach Concorde’s. $\endgroup$
    – StephenS
    Commented Mar 6, 2021 at 23:38
  • $\begingroup$ @StephenS: That's the point :) $\endgroup$
    – user14897
    Commented Mar 7, 2021 at 0:22
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    $\begingroup$ The square-cube law makes large aircraft less efficient, not more. The surface grows slower, but you need to make the structure stronger to hold the weight and the wings must grow faster to produce enough lift and be stronger to carry it and that tips the balance the other way. $\endgroup$
    – Jan Hudec
    Commented Mar 7, 2021 at 9:36
  • $\begingroup$ @ymb1: From a quick search, the MD-80 fuselage seems to be rather larger in diameter than the Concorde: 3.34 m vs 2.88 x 3.32 m. en.wikipedia.org/wiki/McDonnell_Douglas_MD-80#Specifications concordesst.com/dimentions.html $\endgroup$
    – jamesqf
    Commented Mar 7, 2021 at 18:19

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