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 refueling 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 $150 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 airplanes that close to each other.
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 effective,
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 refueling logistics
depend on what kind of aircraft are being flown.
The U.S. 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 U.S.
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'll 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 fueling
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 refueling 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 refueling 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 refueling
is a complicated and dangerous maneuver
that requires a team of highly trained experts
to trust and rely on one another to execute it properly.