FIFI, believed to be the world's last flying B-29 Superfortress, has been grounded as a direct result of engine problems. High repair estimates and associated costs with keeping the storied Boeing aircraft in the skies could mean we've seen the last of a bomber that became an icon of World War II and "the greatest generation." The United States relied heavily upon the B-29 during the latter stages of WWII, utilizing the airship to drop two atomic bombs on Japan before the country ultimately surrendered. Boeing's Superfortress also flew in less violent circumstances: modified versions of the B-29 were used in a number of record-breaking transatlantic flights. Yet as flight technology evolved, the B-29 quickly fell obsolete and would be phased out by the US Air Force in the 1960s.

Until now, FIFI had been something of a flying museum that made stops at air shows and other tour appearances throughout the US. It offered visitors young and old a firsthand look at what had been an incredible feat of engineering in its time, later rising to become an even bigger piece of history. Sadly, repairing the B-29 could cost upwards of $250,000 and that's in addition to massive volunteering efforts required to keep the aircraft operational. For every hour of flight, FIFI commands $10,000 and 100 volunteer hours. Nonetheless a donation campaign has been established in hopes that future generations will have the opportunity to see FIFI as she was intended: in the air.