Originally Posted by
Geriaviator
Agreed, but my point was why Sperry made an instrument that displayed the reverse of all other AH.
At the time, there was no standard. If you're one of the first to come up with something there is no body of work to compare yourself against. Most attitude indicators at the time only showed a single horizon line so Sperry had a choice as to how to portray the sky/ground image on their instruments. Their choice did not end up becoming the industry standard. It is tempting to look back and say 'they did something different' but you're applying hindsight bias when you do that.
