Travel Weekly Blog

All Nippon Airways is asking passengers to use the toilet before flying, in an every-little-helps attempt to cut its carbon emissions.

I did some rudimentary maths, which is the only kind I know, based on the following:

• Average adult bladder holds 400-600ml (so say 500ml)
• A litre of water weighs 1kg, so full bladder weight is around 500g
• Assume everyone arrives with a half-full bladder, so around 250g

Basing it on an ANA Boeing 777-300, which carries 514 passengers, ANA's weight saving is...

• 128.5kg, or...
• The weight of 1.6 adult males (at 80kg each)

Like I say, every little helps. Apparently this will scale up to a five-tonne reduction in emissions every month (across the fleet).

Potential passengers will be relieved to hear that the pre-flight pee is not enforced, merely suggested by staff at the gate.

Perhaps O'Leary's pay toilet idea is actually a brilliant piece of behavioural engineering...