Introduce the concept of King Charles and Queen Camilla, and the numbers go into a tail-spin (even I get queasy).
The motor made an uneven sound, threatening to stall, and the plane went into a tail-spin.
Vainly the pilot strove to avoid the nerve-racking "tail-spin."
"downward spiraling dive of an aircraft," 1916, from tail (n.1) + spin (n.). Figurative sense of "state of loss of control" is from 1928.
in a tailspin