Now that the Garmin Autonomi has been developed and certified the question of how much flying an autopilot can do has been answered. Everything. The Autonomi can autonomously select an appropriate airport, fly the approach, and land the airplane without human intervention or input.

The Autonomi system is intended for emergency use only, but it is the premier example of how capable automatic flight guidance systems can be. Even without autonomous landing capability, the modern autopilot can fly with incredible precision in all phases of flight. And over all but brief periods, the capable autopilot system will be more precise and smoother than the human pilot.

Garmin Autonomi

Garmin’s autoland technology is just the most visible proof that modern autopilots can do it all.

However, without redundant fail-operative systems, the human pilot must hand fly at least some of the time. How does the human pilot retain and practice the skills necessary for precision hand flying while still making best use of the autopilot system? That’s the question.

In single-pilot high performance airplane flying, the standard procedures and training are for the autopilot to fly nearly all of every flight. It’s required that the autopilot system be fully functioning on every single-pilot flight in jets, and on charter flights flown by a lone pilot. And you won’t get past a checkride at any major training facility as a single pilot without using the autopilot in all phases of flight and fully understanding all of its modes and capabilities.

There is historical precedence for autopilot use by a single pilot. When I first started flying jets 40 years ago, the standard procedure was for the pilot flying—the one actually manipulating the controls—to do nothing but scan the instruments and move the controls. If the pilot flying (PF) wanted to look at a chart, tune a radio, review a checklist, or do anything else except look at the flight instruments he handed the airplane to the other pilot.

It was a small step from the concept of the PF doing nothing but holding heading and altitude, the proper airspeed and course to having an autopilot do the same thing when there was no qualified human pilot in the other seat.

It makes sense to me that pilots flying IFR in piston airplanes would benefit from applying the same procedures. By using the autopilot to its fullest capability, the human is freed from the need to concentrate essentially 100% of his attention on maintaining the desired flight path.

Of course, the human must continuously monitor the autopilot actions and performance. But that’s much easier than hand flying full time. You have experienced this anytime you’re flying in the right seat—or sitting in the passenger seat of a car. It’s so much easier to see “what the other guy is doing wrong” from that position than when you’re the one with hands on the controls.

It’s also accepted practice that the autopilot fly approaches with weather near minimums. In fact, reduced minimum category approaches are based on use of automatic flight guidance. And autopilot flight is also a part of approval to cruise in the reduced vertical separation minimum (RVSM) airspace above Flight Level 290. Regulators recognized that when you’re descending to within 100 feet of the runway (or less on an ILS) or maintaining cruise altitude in the thin air above FL 290, only automatic systems have the consistent precision of performance.

But none of this addresses the fundamental question of how we human pilots keep our flying skills—particularly our instrument scan—polished while the autopilot does nearly all of the flying. One answer for pilots of jets is the FAR 61.58 requirement to be trained and checked annually. During that recurrent training you will be expected to use the autopilot fully, but you will also experience autopilot failures in the simulator, typically during critical, high workload phases of flight. If you demonstrate proficiency during those events your skills are up to date.


Jet pilots have to regularly check their scan in simulators, but what about light airplane pilots?

For pilots flying airplanes that don’t require a type rating, there is no FAR 61.58 to check our skills. The flight review every two years is only a review, not a check. And the review can be flown in any class of aircraft you’re rated for, not the most demanding. And it need not be flown under IFR standards even if you’re IFR rated. The flight review is better than nothing, but will only be as beneficial and revealing as the pilot and CFI want to make it.

Many pilots, including me, opt to hand fly much of the departure and climb to cruise. This is a higher workload phase of flight, often with configuration changes, intermediate level-offs, vectors, course changes, and speed adjustments. It’s a pretty good workout of your instrument scan and control precision.

But when the air is choppy and the ATC instructions are changing fast, I look at the instruments and wonder if I’m giving the passengers the best possible ride by hand flying. No matter how hard we concentrate and try to be smooth on the controls, none of us can match the performance of a modern, sophisticated automatic flight guidance system.

One reason is that the autopilot never scans. Dedicated channels continuously track each flight parameter, something our best scan simply can’t do. The word “scan” gives it away. The autopilot never scans because it is 100% dedicated to the task.

Modern autopilots also have very sensitive anticipatory capability. For example, when approaching an altitude capture the system obviously monitors altitude and vertical speed as we humans would. But it also has accelerometers and uses that information to calculate an intercept and level-off limited to no more than a few hundreds of a G, while never over- or under-shooting target altitude. Maybe I get lucky and match the autopilot smoothness sometimes, but it does it every time.

We’re watching these same questions and concerns play out on a very big stage with introduction of autonomous control of automobiles. How to keep the driver involved and in command while also reaping the benefits of automatic control are the burning questions. Sound familiar?

My hope is that with millions of participants in the move toward autonomous driving vehicles instead of the few hundred thousand of us pilots, we will learn more about human interaction and control of automatic guidance systems and all benefit.

Until that happens we’re each as pilots left with the question of how much hand flying practice do we need to be safe and competent while still fully using the safety and comfort capability of the automatic system. After all of these years of flying, I’m still not sure that I know for myself, much less deliver an answer for other pilots.

Latest posts by Mac McClellan (see all)