The widebody weight premium

[exclaimedleech8]

You might think that a bigger plane would need less fuel to haul a given number of passengers than a small one given the square cube rule (as a plane gets bigger, the wetted surface per passenger and hence drag, gets smaller). But you would be wrong

The Airbus A380 has a manufacturer empty weight (MEW) of 285,000 kg and is certified to fly a maximum of 853 passengers for an MEW/pp of 334 kg. The final passenger Boeing 747 had an MEW of 220,000 kg and maximum passenger capacity of 605 for an MEW/pp of 360 kg. Boeing's 777-9, despite having a smaller passenger capacity of 495, delivers nearly the same MEW/pp. The Airbus A350 in its larger variant manages 322 kg of MEW/pp. The composite bodied 787-10 does 307 kg.

Moving into narrow bodies, everything changes. The 737 Max 8 has an empty weight of just 45,000 kg and can carry up to 210 passengers, that's only 214 kg per person. The A320neo does 220 kg per person. And even the very long and now defunct 757-300 could achieve 216 kg per person.

It's pretty consistent; a widebody carries 50% more structural weight per passenger than a narrowbody, presumably because as the diameter of the fuselage increases, you wind up with a lot of vertical space in the cabin that isn't really utilized. This explains why widebodies are so uncommon for domestic flights, even where passenger volumes are very high.

Perhaps if new manufacturing and materials advances allowed for fuselages that were less circular, we would see a move to more widebodies.

 

[red admiral]

Empty weight per passenger as a metric is missing the advantage of the longer range of these widebody aircraft. It's a payload-range difference and not just payload.

 

[Scott Kenny]

Cost per seat-mile is what the airlines care about.

 

[OliverSedlacek]

You can always improve MEW/pp if you reduce range.......

 

[exclaimedleech8]

Cost per seat-mile is what the airlines care about.

And clearly narrow-bodies are cheaper

 

[DWG]

The Airbus A380 has a manufacturer empty weight (MEW) of 285,000 kg and is certified to fly a maximum of 853 passengers for an MEW/pp of 334 kg. The final passenger Boeing 747 had an MEW of 220,000 kg and maximum passenger capacity of 605 for an MEW/pp of 360 kg. Boeing's 777-9, despite having a smaller passenger capacity of 495, delivers nearly the same MEW/pp. The Airbus A350 in its larger variant manages 322 kg of MEW/pp. The composite bodied 787-10 does 307 kg.

You can't compare specs between aircraft without considering range. Even comparing empty weight doesn't work because larger tanks mean larger structure, and then there's hold space to consider. Then there's different structural techniques and the gradual transition from metal to composites, different wing optimisations, different flight controls (neutral stability in pitch means more efficient flight if you have the controls to exploit it, which means less fuel/mile). And so on.

It's not something you can plot on a 2D graph of MEW/pp, it's a real multivariate optimisation, and everyone is looking for a different optimum.

 

[Scott Kenny]

And clearly narrow-bodies are cheaper

It's certainly why twinjets have taken over the industry.

But the long distance routes are widebody territory. LA-Tokyo, for example. Narrow-bodies cannot fly that far.

 

[exclaimedleech8]

It's certainly why twinjets have taken over the industry.

But the long distance routes are widebody territory. LA-Tokyo, for example. Narrow-bodies cannot fly that far.

That doesn't help me on flights from PHX to BOS or EWR to see family

 

[Scott Kenny]

That doesn't help me on flights from PHX to BOS or EWR to see family

Exit Row seats, or pay the premium for Business/First Class.

Same thing I have to do.