Posted by Ward on February 15, 2005
In Reply to: Re: (to go) tits up posted by Bradley King on February 14, 2005
: Another variation is also used in the same context:
: Belly up - could also be referring to the underbelly of an aircraft or boat.
: : : Do not think this means "to fall over on ones back". Rather, "to go wrong". Believe origin is early floating navigation instruments in aeroplanes designed to turn over when not working so as not to mislead pilot. Undersides resembled a pair of tits.
: : Interesting. I've been Googling old aircraft instruments, and the "attitude indicator" on old planes have a W as you described.
As a pilot I can verify the second post above. In the mid century 2000s, when flying on instruments, it was not uncommon for an instrument to fail. A pilot in clouds or weather would then have a real dilemma, and not know which of the instrument readings to believe. So failure modes were developed that left no question that the instrumnet was inoperative....this was one of the solutions.