Final answer:
The altimeter instrument must be inspected for accurate altitude measurement, freedom from sticking or lag, and correct calibration against known field elevation according to 14 CFR Part 43, appendix D.
Step-by-step explanation:
During an annual inspection, in accordance with 14 CFR Part 43, appendix D, the altimeter instrument must be inspected to ensure that it accurately measures and displays altitude, free from sticking or slow operation, and that it corresponds to known field elevation within certain specified tolerances. Additionally, the inspection must verify that the altimeter instrument is appropriately sensitive to changes in air pressure, which reflects altitude changes. The altimeter system includes the instrument itself, the static pressure system, and the altimeter setting indicator. Any leaks or other issues within this system can lead to inaccurate altitude readings and must also be checked.