Flight 19 was a group of five United States Navy TBM Avenger torpedo bomber aircraft from the 20th century. They disappeared without trace on a training flight on 5 December 1945, never to be seen again.
Their disappearance came about when the Monk's TARDIS crash-landed in the Bermuda Triangle, severely damaged by the Titanic. The Seventh Doctor rescued him before the Monk's TARDIS exploded, consuming Flight 19. (COMIC: Follow That TARDIS!)