I enjoy watching this series on Amazon and I need someone smarter than myself to tell me why in a cockpit you cannot add a 50 cent bubble level to the dashboard?

This would be for when there are no visual reference cues and there is a multiple system malfunction the pilots couldn’t look at the bubble before plunging plains into the ground?

While I am very aware system failures are rare, and double failures even more so, this to me seems like a very simple easily added safety feature. What am I missing?

Many episodes I watch involve bad data and pilots reacting to said data when they can’t get a bearing.

I am sure I am overlooking something here and welcome the Reddit education on this matter.

Have at it boys.