Which items are published electronically every 28 days?

• A. Approach plates and high enroute charts
• B. Weather data and NOTAMs
• C. Jet routes and VFR charts
• D. Airport diagrams

Answer: (A)

The main idea here is that certain IFR navigation products are issued on a regular 28-day cycle to keep pilots’ digital charts current. Instrument approach procedures (approach plates) are updated to reflect the latest procedures, frequencies, and obstacle/airspace changes at airports, and they are published on that 28-day cadence so pilots can rely on up-to-date routes into destinations. High enroute charts, which depict the principal IFR routes between navigation fixes and airways, follow the same monthly schedule, ensuring changes in airways or airspace are reflected promptly in the electronic charts pilots use for planning and en route flight.

Weather data and NOTAMs, by contrast, are dynamic and event-driven rather than tied to a fixed publication cycle. NOTAMs are issued as conditions or changes arise, and weather information is continually updated. Jet routes and VFR charts don’t share this same 28-day electronic publication cadence; jet routes are part of the enroute chart set with their own update practices, and VFR charts have separate update schedules.