Investigators continue seeking clues to determine what caused the crash of Asiana Flight 214 in San Francisco on Saturday, in which two girls were killed but 305 passengers and crew survived. Airplane crashes are commonly identified by flight number. Do airlines retire those numbers?
Usually, yes. After a fatal accident, most airlines quietly stop using the associated flight number. The four flight numbers involved in the Sept. 11 attacks—United Flights 93 and 175 and American Airlines Flights 11 and 77—are all permanently retired. (A computer error temporarily revived United Flights 93 and 175 in 2011, but the airlines quickly apologized.) Both Delta and American have stopped using flight number 191, after planes under that flight number crashed in 1985 and 1979, respectively. There are many other examples, such as Southwest 1248, Delta 1141, and American 587. The decision-making process behind flight number retirement, however, is completely opaque. No airline would speak with the Explainer about when and why a number goes out of service. A review of historic accidents, however, suggests that the decisions are made on a case-by-case basis, seemingly guided in part by how familiar the public is with the flight number.
Fatalities don’t seem to be a requirement. US Airways stopped using flight number 1549after Capt. Chesley “Sully” Sullenberger’s “miracle” landing on the Hudson saved all 155 people onboard the crippled plane. American Airlines isn’t currently using number 2253, after a 2010 runway overrun that damaged the aircraft but resulted in no injuries. (It’s also worth noting that airlines regularly change flight numbers for purely logistical reasons, like mergers and changes to the timetable, so the disappearance of flight number 2253 may simply be a coincidence.)
At the time of this writing, Asiana is still using flight number 214. (The flight arrived just over one hour late on Monday.) The continued use of the now infamous number indicates that retirement isn’t an automatic decision.
Brian Palmer is a writer for Slate.