burnt toast
n.— «Smoke in the cockpit is so common that pilots even have a name for it: “burnt toast.” Usually a pilot can find the source of the smoke and get rid of it—much like unplugging the toaster at home—but if not, smoke can have tragic consequences.…“Burnt toast is not that thick of a smoke, but any time you’ve got a burnt toast source that gets enough fuel, it can become a dense and continuous smoke.”» —“Smoke in cockpit is fairly common, pilots say” by Melissa Griggs, M.C. Moewe News-Journal (Daytona Beach, Florida) July 24, 2007. (source: Double-Tongued Dictionary)