In September 1998, Swissair Flight 111 used the call during an emergency landing request following a fume event, which turned out to be an electrical fire that subsequently destroyed the aircraft. Also, in the wake of Avianca Flight 52, the call is frequently used to denote situations where fuel is getting low for given conditions, but not yet at a critical emergency state. Qantas Flight QF-74 used the call "pan pan pan" when it had an engine failure on its fourth engine soon after take off from San Francisco. Qantas Flight 72 (QF-72) issued a pan-pan when the aircraft experienced rapid, uncommanded movements in which the plane dropped several hundred feet without instruction from the flight crew. Several passengers and crew suffered major and minor injuries, and so the call was upgraded to "mayday".