Aircraft inspection due date calculator
Enter when each inspection or check was last done. The calculator shows the last day it is current under the period in the regulation, and how far away that is.
US rules, 14 CFR parts 47 and 91. Leave out anything that does not apply to you.
The rules behind the dates
| Item | Period | How it is counted | Applies to | Regulation |
|---|---|---|---|---|
| Annual inspectionNo person may operate an aircraft unless it has had an annual inspection within the preceding 12 calendar months and been approved for return to service. | 12 calendar months | To the last day of the month | Every aircraft, with the exceptions in 91.409(c) | 14 CFR 91.409(a)(1) |
| ELT inspectionThe ELT must be inspected within 12 calendar months after its last inspection. Its battery has its own date: see below. | 12 calendar months | To the last day of the month | Aircraft required to carry an ELT | 14 CFR 91.207(d) |
| Transponder test and inspectionThe transponder must have been tested and inspected within the preceding 24 calendar months and found to comply with appendix F of part 43. | 24 calendar months | To the last day of the month | Aircraft that use an ATC transponder | 14 CFR 91.413(a) |
| Altimeter and static system testEach static pressure system, altimeter and automatic pressure altitude reporting system must have been tested and inspected within the preceding 24 calendar months (appendices E and F of part 43). | 24 calendar months | To the last day of the month | IFR flight in controlled airspace | 14 CFR 91.411(a)(1) |
| VOR receiver checkThe VOR equipment must have been operationally checked within the preceding 30 days. This one is counted in days, not calendar months. | 30 days | Day by day | IFR flight using VOR navigation | 14 CFR 91.171(a)(2) |
| Registration certificate issuedA Certificate of Aircraft Registration expires seven years after the last day of the month in which it was issued. Use the expiration date printed on your certificate if it differs. | 84 calendar months | To the last day of the month | Every US-registered aircraft | 14 CFR 47.40 |
| 100-hour inspectionFor aircraft that carry a person for hire, or are used for flight instruction for hire in an aircraft the instructor provides (14 CFR 91.409(b)). Counted in hours of time in service, not in days. | 100 h | Time in service now | 14 CFR 91.409(b) |
Written from the published text of Title 14 of the Code of Federal Regulations as read on Nov 11, 2026. Regulations change: read the current section before you rely on a date.
How calendar months are counted
- A period in calendar months runs to the end of the month. An annual inspection completed on any day in March 2026 is current through 31 March 2027.
- A period in days is counted from the date itself. A VOR check on 30 October is current through 29 November.
- The date shown is the last day the item is current, not the day it becomes overdue. On the day after, it has passed.
ELT battery
The battery is not on a fixed calendar. It must be replaced, or recharged if rechargeable, when the transmitter has been in use for more than one cumulative hour, or when 50 percent of its useful life as set by the manufacturer has expired. The new expiration date is marked on the outside of the transmitter and entered in the aircraft maintenance record (14 CFR 91.207(c)). Use the date marked on the battery.
Questions
- When is my annual inspection due?
- On the last day of the twelfth calendar month after the month it was completed. An annual signed off on 10 March 2026 is current through 31 March 2027 (14 CFR 91.409(a)(1)).
- Does a 100-hour inspection replace the annual?
- No. An annual inspection satisfies the 100-hour requirement, but a 100-hour inspection does not take the place of the annual. The annual is performed by a mechanic holding an inspection authorization (14 CFR 65.95) or another person the regulations authorize.
- Can I fly past the 100-hour limit to get to the shop?
- The limit may be exceeded by not more than 10 hours while en route to a place where the inspection can be done. The extra time is included in computing the next 100 hours of time in service (14 CFR 91.409(b)).
- Is the pitot-static check required for VFR?
- The altimeter and static system test in 14 CFR 91.411 applies to operation under IFR in controlled airspace. The transponder test in 91.413 applies to any aircraft that uses an ATC transponder, VFR or IFR.
This page works out dates from what you type. It is not legal advice and it does not say whether an aircraft is airworthy or whether you may fly. The owner or operator is primarily responsible for keeping an aircraft in an airworthy condition (14 CFR 91.403(a)); your mechanic and the current text of the regulations decide.
Keep these dates in one place
Voydar Hangar tracks the same dates for your aircraft on one timeline, puts them in your calendar, and counts hours-based items from your tach readings. It is in a staff test and not open yet.
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