14 CFR 91.409 / 135.419
Annual & 100-Hour Inspection Tracker
Enter your last annual inspection date and Hobbs readings to get the repair deadline, days/hours remaining, and overdue status — with citations.
Annual inspection — 91.409(a)
100-hour inspection — 91.409(b)
Annual Inspection
Enter last annual inspection date above.
100-Hour Inspection
Enter Hobbs readings above.
100-hour overfly rule (91.409(b))
An aircraft may overfly the 100-hour mark by up to 10 hours if necessary to reach a maintenance facility. The excess hours must be deducted from the next 100-hour interval — e.g. if you overfly 5h, the next inspection is due at 95h, not 100h.
Airworthiness Directives (ADs)
This tool tracks inspection due dates only. Applicable ADs must be tracked separately — search the FAA AD database at rgl.faa.gov by make/model. Part 135 operators must comply with all applicable ADs under 91.409 and their OpSpecs-approved maintenance program (135.419).
14 CFR 91.409 · 135.419 · 39.3
Clearspar tracks inspection currency across your entire fleet automatically — before any quote leaves your inbox →
Advisory only. Inspection due dates may vary based on your FAA-approved inspection program (AAIP or CAMP under Part 135). Consult your Director of Maintenance. Not a substitute for your maintenance records.
Frequently asked questions
How is the annual inspection due date calculated?
The annual inspection is due through the end of the 12th calendar month following the month of the last inspection. For example, if the last annual was completed on March 15, 2025, the next annual is due by March 31, 2026 — through the end of March, not exactly 365 days later. This is a calendar-month interval, not a day count.
When is a 100-hour inspection required?
Under 14 CFR 91.409(b), a 100-hour inspection is required for any aircraft used to carry persons for compensation or hire, or for flight instruction for hire. Part 135 charter operations require the 100-hour unless the operator uses an FAA-approved Airworthiness Inspection Program (AAIP or CAMP) under 14 CFR 135.419, which replaces the standard 91.409 intervals with a continuous maintenance schedule.
Can a 100-hour inspection be overflown?
Yes — under 14 CFR 91.409(b), an aircraft may exceed the 100-hour mark by up to 10 hours if necessary to reach a maintenance facility for the inspection. However, those excess hours must be deducted from the next 100-hour interval. For example, if you overfly by 8 hours, the next inspection is due at 92 hours, not 100.
Does a Part 135 operator need both an annual and a 100-hour inspection?
Most Part 135 operators operate under an FAA-approved Airworthiness Inspection Program (AAIP) or a Continuous Airworthiness Maintenance Program (CAMP), which is specified in their OpSpecs (typically A449). Under an approved program, the standard 91.409 annual and 100-hour intervals may be replaced by the program intervals. Without an approved program, both the annual and 100-hour requirements apply.
Do Airworthiness Directives (ADs) count as inspections?
No — ADs are separate mandatory actions issued by the FAA for specific makes and models. They must be tracked and complied with independently of the annual and 100-hour inspections. Compliance with applicable ADs is required under 14 CFR 39.7 and is a condition of airworthiness.
Clearspar tracks inspection status alongside crew currency and MEL deferrals.
The dispatch gate checks aircraft airworthiness — annual, 100-hour, and open MEL items — before any quote goes out.
See Clearspar