Noun
(aviation) The downward, corkscrew-motion of a disabled aircraft which is unrecoverably headed for a crash.
Synonym: graveyard spiral
(figuratively, by extension) The situation or course of action of one who is on a path toward some sort of inevitable catastrophic failure.
Source: en.wiktionary.orgThe American mainstream news media have so far steered well clear of the subject because the phenomenon has been enthusiastically embraced by the talk radio fringe, leading to a death spiral of diminishing credibility. Charles Stross
Is the Collegiate Death Spiral Coming Soon? Source: Internet