- The autopilot relies on a series
of sensors all around the aircraft collecting data.
- [Narrator] This is Captain Sonya Laxo,
a 23-year veteran at American Airlines.
She, like other pilots,
uses autopilot on every flight,
and while it controls.
- The ailerons, the flaperons and the spoilers
on both wings, the elevator on the tail
and then as well as the rudder.
- [Narrator] Autopilot isn't autonomous.
She's here to explain just what it actually is,
how the technology behind autopilot works,
and how it helps her and her fellow pilots get you
to your destination.
(lively music)
Quick note, Laxo flies Boeing aircraft
and will be using Boeing terminology
but autopilot works similarly on other commercial aircraft.
- The technical name for the autopilot
is the Auto Flight Control System, the AFCS.
- [Narrator] The AFCS, or autopilot,
is just one of an increasing number
of automated technologies
in the cockpit, many of which are designed
to prevent dangerous scenarios.
The autopilot system is there to assist pilots,
letting them take their hands off the yoke.
- The main components of the autopilot system
are the autopilot flight director system,
and the auto throttle system,
actually controlled by what we call the mode control panel
in the flight management computer, the FMC,
which we, mot of the time, just call it the box.
- [Narrator] The mode control panel and the box,
those are both controlled by the pilots
on the flight deck.
- By using the mode control panel,
the flight management computer,
we command that autopilot flight director system
and the auto throttle system
to perform the climbs, the cruise, the descents,
the approach, and in certain circumstances,
the actual landing itself.
- [Narrator] But the autopilot system
extends outside the cockpit.
(pensive music)
- [Sonya] The autopilot relies on a series of sensors
all around the autopilot collecting data.
- [Narrator] GPS information, as well as data
on air speed and altitude are fed back
to the computers onboard,
which use the information to determine
if a plane is veering from its preset route.
- [Sonya] The computers are always running.
I mean they're very fast speeds.
So any time there's any little discrepancy,
it's gonna make an adjustment
to keep that aircraft on that flight profile.
- That's the auto part, the system's ability
to make those adjustments to maintain level flight
along a path without pilot input.
- The autopilot's actually controlling the flight controls.
So it's gonna be the ailerons, the flaperons,
and the spoilers on both wings,
the elevator on the tail, as well as the rudder.
- By adjusting those components,
the autopilot is able to move the plane along one
of three axes.
- We have the longitudinal axes from nose to tail,
the lateral from wing tip to wing tip,
and then the vertical,
which goes straight down the middle of the aircraft.
So when the aircraft is rotating on the longitudinal axis,
it's using the ailerons,
the flaperons and spoilers to do that
and then the lateral axis,
that's using the elevators.
And then your rudder will be along the vertical axis.
- [Narrator] While autopilot can move the plane itself,
it's not doing so without supervision.
- The autopilot is a tool.
The autopilot doesn't fly the airplane,
we fly the airplane through the automation of the autopilot.
So while the autopilot is maintaining the wings level,
flying the route,
the pilot is always monitoring the autopilot.
- [Narrator] This relationship can go both ways, however.
Certain autopilot systems prevent input
from pilots that would, for example,
force the plane to turn too sharply
or raise the nose at too steep an angle.
To understand just how a pilot uses autopilot,
let's follow a flight's path,
starting at the gate.
- Initially at the gate,
we download the route into the FMC, the box,
so then the autopilot knows what it needs
to be following as per the route
and also performance, airspeed, fuel consumption.
- [Narrator] The autopilot isn't engaged as yet.
The pilots control the takeoff
but they must engage the autopilot above 28,000 feet due
to vertical separation requirements,
though most pilots press the button sooner,
letting the autopilot take control.
- Analogy would be the cruise control in your car.
So it assists the driver
but the driver still has to be aware
of their environment and react to that environment.
Just like on the flight deck,
we can disconnect the autopilot at any and all time
and have full control of the aircraft.
- [Narrator] But that isn't common.
Pilots typically only spend a few minutes
per trip manually flying the plane,
though they are required to do regular proficiency checks
in a flight simulator
during which certain segments of the flight
must be hand flown.
Once autopilot is engaged, pilots' jobs don't stop.
- We're constantly working on our tasks
to ensure the safety of our passengers,
getting from point A to point B.
We're not sitting up here reading the newspaper.
We don't have time for that.
- [Narrator] Instead, pilots are monitoring the fuel,
planning for emergencies and looking out
for weather ahead,
which could prompt them to change their instructions
for the autopilot.
- We can use it to either go around the weather,
either using a heading mode
or actually making changes into the route itself
to go around the weather.
So the one thing is we're always aviating,
navigating, communicating but with safety
being our number one priority.
- [Narrator] When it comes time to land,
pilots generally disengage autopilot,
and land themselves
but in certain types of weather with low visibility,
pilots are actually required to do an auto land.
- You don't have that visual output out the window,
so that actually helps
but you're again watching it like a hawk
and at any point in time,
if it's not flying the path it's supposed to fly,
we disconnect it.
- [Narrator] Automation, including the autopilot system,
has contributed to record low accident rates
in recent years.
However, it was a faulty flight control system,
combined with pilot missteps and other factors
that investigators say led
to two fatal crashes of Boeing 737 MAX in 2018 and 2019.
Boeing has since fixed the system
and revamped pilot training,
and with the FAA's approval,
the MAX is now being used for passenger flights again.
Meanwhile, airplane automation is continuing
with companies testing out
increasingly advanced systems aimed
at reducing pilot workload and enhancing safety.
But for all its advances,
autopilot still has a lot to learn.
- The autopilot cannot maneuver the aircraft
from the gate to the runway and take off.
Nor can it maneuver the aircraft
from the runway back to the gate.
- [Narrator] For now, think about autopilot
as an extra set of hands in the air,
following Laxo's detailed instructions.
(lively music)