New York tourist: "Pardon me sir, can you tell me how to get to Carnegie Hall?"
New Yorker: "Practice, practice, practice!"
Practice is not just the way to get to Carnegie Hall. It may well save your bacon some dark and stormy night when the automation stops working and you take center stage for a surprise solo performance.
It should come as no surprise that flying on instruments, like playing a musical instrument or an athletic endeavor, is a skill that erodes with the passage of time and non-use. Simply knowing
how to do it, is not a guarantee that you still
can do it.
FAR 61.57 spells out the minimum recency of experience requirements for instrument pilots, wherein every six months a pilot must have performed six instrument approaches, holding procedures and tasks, intercepting and tracking courses through the use of navigational electronic systems. If one is using an "aviation training device", it calls for an additional three hours of instrument experience and four unusual attitude recoveries, all within two months.
These regulations do not mention the use of automatic systems, but one could logically conclude that since they date back from a time where autopilots were rare or crude, the true intent was that it was the pilot who was operating by reference to instruments, not the machine. I doubt that programming an FMS and autopilot to do the flying was envisioned as the way these requirements would be fulfilled.
Perhaps ironically, pilots of part 121, 125 and 135 are exempt from the instrument recency requirements (see appropriate regulations for details).
Due to perceptions, policies, or procedures, the airline pilots of today's highly automated airplanes do very little hand flying, often not much more than a few seconds after takeoff and a few brief minutes before landing. For long haul flights especially, this reduces the percentage of the flight that is hand flown to mere fractions of 1%. But these pilots are not exempt from the human factors that deteriorate their skills from non-use, just like other mortals.
Pilots who learned to fly using highly automated aircraft may not have the a solid base to call on like some of us "old timers" with thousands of hours of autopilot-free round dial experience.
In the "it's not just my opinion" department, here are four links to some light reading on the subject of loss of pilot skills: (I've arranged them from shortest to longest).
