- The US Air Force uses a process called aerial refuelling to transfer fuel midair from one aircraft – the tanker – to another aircraft – the receiver.
- It is an inherently dangerous manoeuvre to get two aeroplanes that close to one another and s ome of the refuelling logistics depend on the type of aircraft.
- Watch the video above to see how it’s done.
Narrator: Fighter jets can perform what seem like impossible maneuvers, high above the clouds. But one of the most amazing moves is how it can refuel in midair.
Aerial refuelling is the process of transferring fuel from one aircraft, the tanker, to another aircraft, the receiver. It allows the Air Force to conserve fuel by not forcing fighters to seek out and land on a runway in the middle of a mission. It’s not that easy. If you think threading a needle is hard, imagine doing it while piloting a $US150 million fighter jet.
Mike Vilven: This is all in the name of safety, obviously, because it’s an inherently dangerous activity when you get two aeroplanes that close to each other.
Narrator: That’s Major Mike Vilven. He evaluates pilots who have trained on the KC-135 Stratotanker.
Vilven: Before we even take off, there is anywhere from two to four hours of mission planning and preparation that go into what we’re actually going to do.
Emily Kubusek: It is paramount that our pilots are safe, and they are challenges, and they know exactly the procedures that they’re doing before they actually execute.
Narrator: And Major Emily Kubusek is a KC-135 instructor training the next generation of pilots. Some of the refuelling logistics depend on what kind of aircraft are being flown. The US Air Force uses a flying boom system, where a long, thin tube extends from the tanker into a receptacle on the receiving aircraft.
To begin, the pilots consider what they call altitude block, which are like little roads in the sky, permanently laid out at different altitudes all over the US The pilots agree on a starting point, an end point, and a meetup time.
The tanker generally arrives about 15 minutes before the receiver, who will arrive about 1,000 feet lower than the tanker. But they will close that distance pretty quickly.
Vilven: And they’re flying what we call a racetrack pattern, where they’re just flying in a circle, waiting for the receiver to show up. Both the tanker and the receiver will continue down the track. They’re a mile behind the tanker, a thousand feet below, and then they usually start to close in. They decrease that altitude separation until they get to the astern position, which is about 50 feet behind the aircraft, at which point the boom operator, they are directing the receiver at that point to close in for the contact.
Kubusek: That’s when the boom operator will take over and will tell them come in, go out, go faster, go slower, up or down, until they’re in the sweet spot, and then that boom operator can make the contact with that boom.
Narrator: The boom is what will run the fuel from the tanker to the receiver. Jets like the F-22 and F-35 have boom receptacles for receiving the fuel from the boom.
Kubusek: Generally, while the boom operator is in the back doing all of the hard work, the pilots are up front. One person is actively flying or actively monitoring the autopilot, and then the second pilot is usually off-loading the gas when everything aligns correctly.
Narrator: The boom operator has full control over the boom, and can extend and retract it as needed. The operator can disconnect the boom when fuelling is complete, but if the receiving plane moves off track, the system triggers an automatic disconnect.
This is very helpful, because inclement weather, turbulence, unexpected turns, and air traffic can all make it difficult to stay connected.
Sometimes the planes will have to separate and rejoin in the middle of the process. Once the refuelling is finished, the receiving plane drops 1,000 feet, then coordinates with the tanker for departure from the formation.
The planes can then continue on their respective missions. A slightly easier aerial refuelling method is the drogue probe, used on almost all of the Navy and Marine fighter jets. A drogue fire hose with a parachute on the end comes out of the tanker, while the receiver extends a thin probe into the parachute, like a bullseye.
No matter the method, aerial refuelling is a complicated and dangerous manoeuvre that requires a team of highly trained experts to trust and rely on one another to execute it properly.
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