Can An Airliner Really Land Itself?

AutoLand-splashor Who (or what) is flying this thing, anyway?

There has been a lot of talk in the media lately about aircraft automation. Apparently, The Machines are doing the flying and the pilots are sitting around drinking coffee and working Sudoku puzzles.

I’m happy to report the rumor of pilots relinquishing control to The Machines has been grossly exaggerated…

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What can the autopilot do?

The most misunderstood system that pilots use is the autopilot. Autopilots do a great job of reducing pilot workload, but they can’t think.

Here’s what a typical airliner autopilot can do:

  • The autopilot can steer the aircraft on a heading or pre-programmed course.
  • It can be instructed to climb or descend the aircraft.
  • When everything is set up properly, the autopilot (working with other systems) can help land the airplane.
767MCP
767 Mode Control Panel. This controls the flight directors, autopilot, and autothrottles. Three redundant autopilots are engaged with the buttons at the top-right.

The autopilot is a “dumb” system and cannot adapt to changing conditions during a flight. When flying into busy airports, heavy traffic and bad weather will require the crew to change the airplane’s direction, speed and altitude. Human pilots must manage these changes. Should we decide to use the autopilot to reduce our workload, we have to tell the autopilot what we want it to do. The autopilot may be physically manipulating the aircraft’s flight controls, but human brains are still doing the planning and management.

Typical Approach and Landing

Autoland-clear-crop
Typical view at 100 feet on a nice day

Planning for any approach and landing begins during the cruise portion of flight. We discuss what runway we are landing on, the type of approach in use, the current weather, and other  factors that will affect our arrival like taxiway closures and aircraft maintenance issues. We typically begin final approach using the autopilot and the airport’s electronic approach system. After flying through a few layers of clouds, we catch site of the runway about 4 or 5 miles out. The pilot flying will then turn off the autopilot and hand fly the jet to the runway for a nice, smooth landing. Hand flying (flying the airplane without the autopilot) is not only fun, it’s an important skill we need to maintain.

The majority of landings you’ll experience as a passenger are flown by hand. When the landing is especially smooth, be sure to compliment your flight crew as you exit. If it’s a rough landing, remember: It’s not the captain’s fault; it’s not the first officer’s fault… It’s the asphalt!

The Autoland Approach and Landing

1/8 mile visibility
An 1/8 mi visibility autoland at 100 feet

Sometimes, heavy fog or snow will cause low visibility at the destination. So low that we can’t see the runway until the main wheels have touched down. The game now changes. With visibility this low, it’s not possible for a human to hand fly the airplane to the runway. The flight crew needs to perform an “autoland.” Our previous 5 minute approach brief now turns into a lengthy review of a multi-page checklist. A colleague of mine describes it like this: “An autoland at our airline is a well orchestrated ballet involving pages of preparation.

To get an idea of what we can (and can’t) see during a low visibility autoland, compare the two flight deck images above. Both are taken at about 100′ above the ground. The bottom image shows what we see with 1/8 mile visibility caused by fog. Look very closely and you can see the runway and some lights (click the image for a larger view). Now consider that we are moving towards this runway at over 160mph. We definitely need a little help from our automation to land the airplane.

A safe autoland requires that both aircraft and flight crew work together perfectly.  As the autopilot brings the airplane closer to the runway, our eyes are carefully scanning for any anomaly, warning flag, or status message that might indicate a problem. With the exception of a few well rehearsed call-outs, the cockpit is dead silent. After touch down, the autopilot will continue to steer the aircraft down the center of the runway until the captain disengages the automation and takes over to taxi.

The Autoland Button? Sure! These days, those airliners land themselves!

Where did they put this thing?
Where did they put this thing?

I often hear non-aviation folks talk about pilots simply pushing a button to make the airplane land itself. If we have an autoland button, I haven’t seen it!

There are several systems on our airplane that must be properly set up before the aircraft can make a successful autoland:

The approach frequency, speedbugs, autobrakes, landing gear, flaps, spoilers, autopilots (we have three), altitude select, and missed approach procedures all must be programmed, armed, engaged, dialed up, and loaded. Whew! We are busy during every approach, but even more so before and during a low visibility autoland.

Setting up an approach
This stuff is set up on EVERY approach (including autolands)

An “autoland button?”    Nope.

Planning for a failure.

Airliners are really reliable. Crews successfully perform autolands in bad weather dozens of times a day worldwide. We rarely have problems with them (maybe one in a bazillion?). However, when we prepare for this type of approach, we plan for failure. As they say, sometimes stuff happens. What happens if an engine fails during the approach? What if the airport’s electronic guidance system goes kaput? What if one of our electrical systems goes haywire? We practice all these scenarios in the simulator. During a real autoland approach, we aren’t on a coffee break; we are ready and waiting for trouble. If a problem does occur, we will immediately take manual control of the airplane and climb away from the ground. Once we are at a safe altitude, we can address the problem then fly the approach again to make a safe landing.

So what’s the answer? Can an airliner land itself?

When properly set up, the autopilot and other automated systems can land an airliner on the runway – and pretty darn smoothly, too.  As impressive as that sounds, these systems still require humans to plan, set up and monitor them. They also require humans to intervene when things don’t go exactly as planned. Bottom line… the pilots have not relinquished control to The Machines. You’re in good hands.


A very special thanks to Zach Williams for creating the B-767 flight deck images used in this post! Zach stayed up late and was exceedingly patient with my obsessive/compulsive demands.  Images were rendered using Microsoft Flight Simulator X with Flight1 Software’s Level-D 767.

17 Comments

  1. Nice article! Your blog is a joyous find! It’s funny I’ve written a few articles about “Otto Pilot” AND HAL 9000, LOL! I pretty much say the same thing: the Autopilot is nothing more than a 3D Cruise Control! It processes, but doesn’t think! I know you follow my blog so I don’t think it will be too tacky to share a couple related links (from my old blog) here:

    http://capnaux.blogspot.com/2012/05/busted-aviation-myths-2-otto-is-my.html
    http://capnaux.blogspot.com/2013/07/happy-4th-future-of-us-aviation.html

    I enjoy your work; I’ll add you to my new blogroll! 🙂

    Eric “Cap’n Aux” A

    • Hi, Eric! Thank you for the nice comments. I’ve enjoyed watching your videos, they are really well done! Your new site is looking good; everyone should take a peek: http://capnaux.com

      From reading a few of your posts, it’s easy to see that we get similar questions at cocktail parties. 🙂 What would we do without good ‘ole HAL!

      Thanks again for reading AeroSavvy and adding me to your blogroll. I need to set up a links page or something similar so I can reciprocate. Keep up the great work on CapnAux.com!

  2. About a decade ago, I heard avionics engineers mentioning that some in the avionics industry were investigating a kind of “emergency autoland” button. Recall that this was after the 09/11 terror attacks, and people were looking for solutions. The rationale was that if somebody took passengers or attendants hostage, and intended to blackmail the pilots, the pilots could engage an irreversible landing to a diversion airport.

    I doubt that much came out of these thoughts.

  3. I’m guessing the autoland feature can’t lower the gear since, at least on some Boeings, the physical switch in the midpoint disables the hydraulics. I presume to automate that would require adding an electrical mechanism to physically move the gear lever (out, then down). I’d also assume that Boeing at least would make the flap handle move to indicate the current flap setting if they were automating that (given that they tend to have the physical controls echo what the autopilot is doing). Is that correct? If so It’d be an example of the coordination requirements between pilot and the autoland system.

    • Hi Kendall,

      On the 757 & 767s that I fly (as well as earlier Boeing aircraft) the gear and flaps can not extend without a mechanical action performed by a crew member. To automate the gear and flaps on these airplanes, some major engineering changes would be required. The autoland system has no idea what the gear and flap positions are or what they should be. So, in order to automate these controls, a completely new system of some sort would need to be designed and installed… not going to happen!

      I’m not familiar with the new generation of Boeings (777-9x, 737Max, 787). These aircraft may have been designed to better accept future automation advancements.

      Thanks for reading!
      Ken

  4. Thanks, Great article..
    I was in an airport taking my sister and Brother in law to catch their Flight to Poland from SFO..I heard some people talking about planes.. I have worked on military aircraft in my younger years on KC-135, F-111’s A-10, T-38’s F-106 and in General Aviation which includes, Aero Commanders, Falcons and Citations that my former Boss owned and flew.. hearing these people talking about planes had me laughing..As I chuckled to myself, my sister and brother in law asked me what’s funny.. I explained to them what the group of people were talking about and knew absolutely nothing.. So i got up and walked over to the group and got involved in their conversation, as a joke..

    after listening to them, I told them what experience I had working on planes.. as i gained their confidence, I pulled out the auto button card.. I said, all the new planes, pilots dont even take off or land the planes.. the purpose of pilots now is safety.. all they do is watch the gauges encase of something happens.. for take offs the pilots responsibility is go over the check list and make sure everything is functioning correctly. they taxi out to the runway while in holding they program the flight plans into the computer and when they taxi onto the runway they push the take off button.. once they are in the air they switch on the auto pilot, when on approach for landing they push the auto land button.. they were sucking it up.. i said if you dont believe me, I pointed to a couple of pilots and flight attendants finishing their meal at a restaurant. I said ask them, they love to discuss how their planes fly! So they did and I went back to my sister and brother in law, laughing and told them what i said.. my sister said i was mean, I said wait and watch, what the pilots tell them.. As I sat there, and watched, the look on the pilots faces were priceless, they and the attendants busted up laughing and apparently they asked who told them, the group turned and pointed at me.. the pilots instructed them as you stated and when they got done, giving them a tutorial, they came over and said that was a good one, they actually thought the plane fell itself!

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