There is a reason that luggage has to be weighed. If you watch Mentour Pilot, there's a not insignificant number of plane accidents (and outright disasters) that occur due to the plane weight being calculated incorrectly, and thereby running out of fuel.

https://www.evionica.com/blog/blog/how-much-the-passenger-we...

Hehe, I remember doing stuff like wearing 8 t-shirts back in the day to try and travel for £1 around Europe.

Currently feel like I'm living on the edge by 1-bagging an Osprey Farpoint 40. My heart races every time I'm at the gate, and I feel I've perfected a masterclass in illusion by angling my body, distracting the gate staff, moving my hands to draw attention, etc (note: I probably look like an idiot - but it's fun to dream).

The optimal solution is just to weigh everybody as they board the plane and bill them accordingly, lol. But I don't think that'd go down too well.

If these jackets can hold 5kg, and there's 200 passengers donning them, that's a ton of weight, which is about $100 per flight in extra fuel?

Wonder if the fairest way to charge for this is aa ringfenced externality tax on the product itself; calculating the average amount of fuel such products burn in an average lifespan. Would be preferable to airlines dictating what you can and can't wear...