[thaumasiotes]

> For ashtrays being removed.

I don't think it's safe to generalize from this to a functional aspect of the plane. Removing the ashtrays serves no purpose, so there's no cost to letting it wait for a decade or two. Improving the aerodynamics does serve a purpose and might be done faster.

[bombcar]

At least one total loss was caused by a waste fire in the lavatory from a cigarette-the ashtrays are mandatory safety equipment and the FAA won’t let you fly without them operable.