August 10, 2012
The autopilot has to be one of the greatest inventions to come down the pike for pilots. The first plane I owned (actually I owned half of it), was a 1969 Cherokee 180D, N7728N, and it had a very rudimentary autopilot. It could hold a heading that I set with a moveable “bug” on the directional gyro. It wouldn’t hold altitude, and it sure wouldn’t fly an instrument landing. But just the ability to hold heading was a great thing to have, especially when flying alone in the clouds. It allowed me to consult my maps without worrying about drifting off heading or entering a gradual spiral.
The autopilots in modern jet aircraft can fly the plane from shortly after takeoff all the way to landing. But contrary to the image that many people have, it’s not just a matter of pressing a button, then forgetting about it (despite the old pilot’s joke when engaging the autopilot, “Let George fly it.”) In truth, the pilot tells the autopilot what to do throughout the flight by setting inputs for both the lateral and vertical modes.
The minimum altitude at which the autopilot may be engaged varies among airlines. My company’s minimum is 200 feet, but I don’t think I’ve ever seen a pilot engage it that low. Occasionally I’ll see someone engage it by 1,000 feet, but most pilots hand-fly the plane until much higher, often above 18,000 feet.
Once engaged in LNAV (lateral navigation), the autopilot will follow the entire flight plan that’s been loaded into the plane’s computer. The third dimension, altitude (vertical navigation, or VNAV), will also be flown according to the flight plan, but no altitude change occurs until the pilot sets the desired altitude on the mode control panel (the “dashboard”).
The autopilot does an excellent job of delivering a very smooth flight, and its use frees up the pilots to manage and monitor the flight. For the majority of the flight, the pilots’ involvement in flying the plane is initiating altitude changes, occasionally deviating from the planned flight path (e.g. due to weather) by flying in heading mode (as opposed to LNAV mode), and making changes to the stored flight plan in response to clearances from ATC (e.g. “You are cleared direct to Albany” or “After Brickyard, proceed direct Wilkes-Barre VOR”).
Most pilots will turn off the autopilot and hand fly the approach and landing. I’ve occasionally clicked it off as high as 20,000 feet, but usually I’m somewhere below 5,000 feet. Many modern planes have autoland capability, the ability to fly an ILS right down to landing. Using this feature is not just a matter of watching it happen. The pilots must configure the plane with flaps and landing gear, as well as ensuring that it slows to the proper speeds.
You might think we’d use this capability a lot, but most pilots like landing the plane themselves, and I’ve only used autoland one time in a real-world situation of very low visibility (fog at LAX; we could barely see the taxiway lights after landing as we made our crawl to the gate). Sometimes our flight plan will contain a remark from the dispatcher asking us to perform an autoland in order to keep the plane certified for this capability, and in this case we will grudgingly comply if the winds and runway in use allow it. We always remain ready to take over in case it doesn’t perform satisfactorily.
Lately, there’s been some concern that reliance on automation is eroding the basic skills of pilots. There is some truth there. My first airline job was flying the Jetstream 32, a 19-seat turboprop. I remember being amazed that it had no autopilot whatsoever, not even something as simple as a bug tracker like the one I had in my Cherokee 180. I hand flew that plane for five years, and I can honestly say that my flying skills and instrument scan probably peaked during that time. Hand flying five to eight legs a day, down low in the weather in the northeast corridor, will hone one’s flying skills.
Contrast this with my situation a couple of years ago, when I was on a steady diet of international flights. I would fly four trips a month, for a total of eight ocean crossings. With a three-man crew, I would be lucky to be the flying pilot on three of those flights, and often I would only get two takeoffs and landings in a month. In my turboprop days, I would sometimes get twice that number in a single day.
But the thing is, if you reach a certain experience level you’re not going to forget the basics, just like riding a bike. The problem today is that pilots new to the industry are starting right out in very sophisticated jets with glass cockpits, and, of course, a fully capable autopilot. The training focuses on using the automation, and less emphasis is placed on hand flying and the use of raw data. For a generation raised on computers and video games, mastery of this equipment comes quickly. But I sometimes wonder if the stick and rudder skills are there.