Point of no return


The point of no return is the point beyond which one must continue on one's current course of action because turning back is dangerous, physically impossible or difficult, or prohibitively expensive. The point of no return can be a calculated point during a continuous action. A particular irreversible action can be a point of no return.

Origins and spread of the expression

The phrase "point of no return" originated as a technical term in air navigation to refer to the point on a flight at which a plane is no longer capable of returning to the airfield from which it took off.
It can also mean the instance in which an aircraft taxis down a runway, gaining a certain speed, and must become airborne in lieu of a crash or explosion on the runway —for example, Charles Lindbergh's takeoff in The Spirit of St. Louis in 1927 in which there was uncertainty about the plane's ability to take off from a 5,000 foot mud soaked runway while fully loaded with aviation fuel.
The first major metaphorical use of the term in popular culture was in the 1947 novel Point of No Return by John P. Marquand. It inspired a 1951 Broadway play of the same name by Paul Osborn. The novel and play concern a pivotal period in the life of a New York City banker. In the course of the story, the character faces two "point of no return" realities: first, that his quest for a big promotion will mean either triumph or a dead end to his career, and second, that he can never go back to the small-town life he abandoned as a young man.

Related expressions

There are a number of phrases with similar or related meaning:
The Point of Safe Return is the last point on a route at which it is possible to safely return to the departure airfield with the required fuel reserves still available in the tanks. Continuing past the PSR, the aircraft must either land at the aircraft's intended destination, or to divert and land at another nearby airfield should an emergency arise.
The following expressions also express the idea of a point of no return.