The short answer
A progressive inspection breaks the complete aircraft inspection into scheduled segments performed throughout the year instead of one large annual event. It's an FAA-approved alternative under 14 CFR 91.409(d), used mainly by high-utilization operators to reduce downtime.
How it works
Instead of opening the entire aircraft once a year, an approved progressive program divides the full inspection scope into phases — for example four phases, one every 25 hours or few months — so the whole aircraft is completely inspected within each 12-month period while individual downtimes stay short.
The program requires FAA approval, a detailed schedule, and disciplined tracking: each phase has its own due point, and falling off the schedule can revert the aircraft to the standard annual requirement.
Related terms and reading
Keep every hour and inspection straight
Maggneto tracks engine times, inspections, and ADs from your actual logbooks — so terms like these become numbers you can act on. Browse the full maintenance glossary.