After passing inspection, when must the static pressure system and altimeter be re-inspected for IFR use?

The requirement for re-inspection of the static pressure system and altimeter for IFR (Instrument Flight Rules) use is established by regulations set forth by the Federal Aviation Administration (FAA). After a successful inspection, these systems must be re-inspected every 24 months to ensure continued accuracy and safety during flight operations.

The choice indicating "January 31, 2 years hence" aligns with the regulations, which specify that the inspection intervals are typically measured in months from the date of the last inspection, with 24 months being a standard timeframe. Since inspections are due every two years, if an inspection takes place in January of a given year, the next inspection would be scheduled for the end of the same month two years later—hence, January 31 of the year two years later.

This timing is important as it keeps the aircraft and its systems compliant with IFR regulations, ensuring safety and operational integrity. Therefore, the choice that reflects this two-year inspection period accurately is the correct answer.