A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2019 Jan 21, 13:00 -0800
David Pike, you wrote:
"Incidentally, the earliest Constellations had astro domes. They were also arguably the first pressurised passenger aircraft in regular use. Legend has it that one of these astro domes popped off under the pressure taking the unfortunate navigator with it. This might well have given the impetus for the development of periscopic arrangements in pressurised aircraft. "
It may have been only legend for a few decades in the middle, but it's well-documented now. See March 10, 1947 in this incident list:
https://en.wikipedia.org/wiki/List_of_accidents_and_incidents_involving_the_Lockheed_Constellation. It's come up more than once in NavList discussions.