This five-engine Boeing 747 is among the rarest aircraft ever built, and it has a very specific role
Published on Jul 31, 2025 at 8:12 AM (UTC+4)
by Keelin McNamara
Last updated on Jul 30, 2025 at 7:13 PM (UTC+4)
Edited by
Tom Wood
This five-engine Boeing 747 is one of the rarest aircraft that you will ever see.
The shorter, stubbier 747 (the Boeing 747SP) was the choice for airlines that wanted a smaller widebody and more range.
Today, just two of the five-engine Boeing 747 engines remain in active service.
And they both serve a very specific and important role in the skies.
DISCOVER SBX CARS: The global premium car auction platform powered by Supercar Blondie
Five-engine Boeing 747 serves key purpose
Seeing a Boeing 747 is a truly treasured sight for any range of airplane fan.
But seeing its forgotten sibling is like catching a white whale in the wild.
The five-engine Boeing 747SP currently has just two planes still actively flying today.
Both of these five-engine Boeing 747 planes are owned by Pratt and Whitney Canada.
But these planes are far from museum relics – in fact, they are the opposite.
These final five-engine plane units are used for a very special and important purpose.
Pratt and Whitney’s 747SP units are known as flying testbeds.
And that is because they are used as flying laboratories that test new engines.
The development process for a jet engine is, naturally, a very long and comprehensive one.
It requires substantive amounts of testing before it can be deemed airworthy.
Due to its capacity, the five-engine jet is able to help with this process.
The process starts with a static test, whereby the engine’s modules and componentry are tested without the engine running.
Once the first phase is passed, the new engine is put through its paces on a giant engine stand on the ground.
Engineers put the engine through its paces inside a building or a wind tunnel, and make the appropriate changes.
Installing an engine onto a testbed aircraft allows engineers to pull live data from the engine as it’s running.
Boeing 747SP born out of request from airline
The Boeing 747 itself is arguably the most iconic airplane in the history of air travel.
Production of the 747 began in 1967, with its first test flights taking place in 1969.
The first units of the 747 began being delivered to Pan-Am at the beginning of 1970.
Pan-Am is also the legendary airline responsible for creating the five-engine 747SP.
The SP, which stands for ‘Special Performance’, was specifically requested by Pan-Am.
Pan-Am wanted an airplane that was capable flying from the U.S. to the Middle East non-stop.
Boeing obliged – and the five-engine Boeing 747 was born.
Today, Pratt and Whitney’s two examples remain the only two active in the skies.
Keelin McNamara is a content writer at Supercar Blondie from Ireland, covering cars, technology, and lifestyle. Despite being a Law graduate, he discovered his passion for journalism during the COVID-19 pandemic, and has worked in the industry ever since. Outside of work, he is an avid MotoGP fan, and is a self-confessed addict of the sport.
