[TylerE]

Incorrect. In level flight the wings have - by definition - 1g of upward load. Regardless of speed or altitude.

[FabHK]

That’s what sand worm was saying - level flight puts less stress on the wings than takeoff (where you accelerate vertically, thus have more than 1g).

Still, you don’t want to take a structurally damaged plane high up.

[nutcracker46]

Consider cabin pressure differential versus the outside ambient air.

[sandworm101]

1g in up/down force. But thicker air means more forwards/back forces. Higher engine power = more force, regardless of G.

[TylerE]

Engine power is a fraction of weight. Even at full thrust (which is rarely used in commercial service, even for takeoff), the engines are only capable of 0.25g or so.