Another one of those Schrödinger’s jokes.

*Technically* they were engineered from the ground up to send a small projectile as far as possible using a chemical reaction.

I’m referring to this bit: they are not technically engineered to simply shoot a projectile. They are engineered for a specific purpose, which is to kill people. Your comment sounds like you want to downplay the role of requirements in the engineering process, like a lot of people here do.

You don’t know the first thing about requirements engineering. Technically, these assault rifles are primarily designed to kill/injure people, it’s 100% part of the stakeholder/requirements analysis in their systems engineering workflow.

An airliner is not designed to fly through the air. It’s designed to transport people and cargo from A to B within a given amount of time. Flying is just a means to achieve it.