The term "charts" is not found in the FAA's Part 91 regulations (other than for large and turbine-powered multiengine airplanes in 91.503[a]. The specific FAA regulation, FAR 91.103 "Preflight Actions," states that each pilot in command shall, before beginning a flight, become familiar with all available information concerning that flight. What is not specifically addressed in the regulation is a requirement for charts.

You should always carry a current chart for safety's sake. An expired chart will not show new frequencies or newly constructed obstructions, some of which could be tall enough to be a hazard along your route of flight.

The only FAA/FAR requirements that pertain to charts are:
    Title 14 CFR section 91.503[a] (Large and Turbojet powered aircraft)
    Title 14 CFR section 135.83 (Air Carriers-Little Airplane)
    Title 14 CFR section 121.549 (Air Carrier-Big Airplanes)

The FAA has rendered interpretations that have stated the foregoing.

The subject of current charts was thoroughly covered in an article in the FAA's July/August 1997 issue of FAA Aviation News. That article was cleared through the FAA's Chief Counsel's office. In that article the FAA stated the following:

"You can carry old charts in your aircraft." "It is not FAA policy to violate anyone for having outdated charts in the aircraft."

"Not all pilots are required to carry a chart." "91.503 requires the pilot in command of large and multiengine airplanes to have charts. Other operating sections of the FAR such as Part 121 and Part 135 operations have similar requirements."

..."since some pilots thought they could be violated for having outdated or no charts on board during a flight, we need to clarify an important issue. As we have said, it is NOT FAA policy to initiate enforcement action against a pilot for having an old chart on board or no chart on board." That's because there is no regulation on the issue.

..."the issue of current chart data bases in handheld GPS receivers is a non-issue because the units are neither approved by the FAA or required for flight, nor do panel-mounted VFR-only GPS receivers have to have a current data base because, like handheld GPS receivers, the pilot is responsible for pilotage under VFR.

"If a pilot is involved in an enforcement investigation and there is evidence that the use of an out-of-date chart, no chart, or an out-of-date database contributed to the condition that brought on the enforcement investigation, then that information could be used in any enforcement action that might be taken."

If you, as an FAA Safety Inspector, Designated Pilot Examiner, Flight Instructor, or other aviation professional are telling pilots something other than the foregoing then you are incorrect.