Why do some Boeing 747s have a fifth engine?
The 747 left wing was designed to be able to carry an extra engine, which made moving spare engines between airports for maintenance and delivery a far more convenient process. No expensive air freight or slow over the ground freight to deal with. Airlines bought the original 747 primarily for its range, not its capacity. The advent of long-range twin-engine jets, notably Boeing’s own 777, took away the 747’s range advantage.
What’s the oldest 747 still flying?
Older But Grounded: Mahan Air’s 747-400 EP-MNB While Kalitta’s N740CK holds the title for the oldest operational Boeing 747-400, another 747-400, EP-MNB of Mahan Air. Built and delivered in August 1989, this aircraft preceded N740CK by two months. However, as of 2025, it is currently stored and not flying. Using data from ch-aviation, this aircraft, registered as EP-MEE, took its first flight on August 31st, 1990, and entered commercial service 19 days later, meaning that it will be reaching 35 years of age in 2025. This makes it the oldest passenger Boeing 747 in the skies today.