Push the envelope

Posted by Bruce Kahl on September 18, 1999

In Reply to: Push the envelope posted by Tom Logan on September 18, 1999

: I'm wondering the source and derivation of this phrase. Any ideas?

This expression comes out of the US Air Force test pilot program of the late1940's.
The envelope refers to a plane's performance capabilities. The limits of the plane's ability to fly at speeds and altitudes and under certain stresses definewhat is known as its performance envelope. It's an "envelope" in the sense that it contains the ranges of the plane's abilities.
"Pushing the envelope" originally meant flying an aircraft at, or even beyond, its
known or recommended limits.
The expression was popularized by Tom Wolfe in his book "The Right Stuff" and later the movie of the same name.