When you view your currency on MyFlightbook, you often see an expiration date next to a currency. The dirty little secret here, though, is that it's a fiction. Most currency doesn't technically ever expire. It's something you have or you don't have, and it's generally backwards-looking. (The discussion below is entirely in the FAA context, but it largely applies as well under other regulatory environments).
Generally, when I compute a currency, I'm asking 2 questions:
- Can you exercise the privileges that require this currency today, and
- What is the last day that you can exercise those privileges based on what is in this logbook as it is right now.
A simple example is to imagine that you did 1 takeoff/landing* on Jan 1, another on Feb 1, and a third on March 1. As I write this, it is March 28, 90 days ago is December 28 2025. So if I look back 90 days, I will see all three takeoff/landing pairs, and thus you are current per 61.57(a). Now I ask "what is the last day when that will be true" and the answer is April 1, because on April 1, the preceding 90 days will include all three flights, but on April 2 the preceding 90 days only goes back to Jan 2 and thus only encompasses the latter two flights. So your "expiration" date is April 1.
Does that mean that your currency expires on April 1? No - if you do two more takeoffs/landings on March 29, then you will be current until June 27, assuming no more flying. So the "expiration" date continuously moves based on your flying; it's not something that exists on its own.
I realize that this can be an esoteric distinction, but it is a source of confusion, particularly because currencies can have multiple such "expiration" dates!
A great example here is instrument currency (61.57(c)). You can be current by virtue of doing the 6 approaches/holding in 6 months, or you can be current by virtue of having had an IPC. These can each "expire" on different dates! Indeed, I get questions from pilots who click on a currency to see the flights that contributed towards its computation and don't see the flights they expect to see, and it is often because they are thinking of one path but the one MyFlightbook used was from another path. MyFlightbook computes all of the paths and reports as the expiration date whichever is the latest; in the event of a tie, one path is picked arbitrarily. A question I received just last week was from a pilot who thought his simulator sessions weren't counting because when he clicked on his instrument currency, it showed him his instrument checkride rather than the flights with approaches/holding. In his case, both paths yielded the same date, and the system picked the checkride.
Another example is 61.57(e), which is a complicated alternative to 61.57(b) pilots to remain night current for some turbine operations. I won't go into the details of 61.57(e), but it can extend night currency for up to 12 months, but MyFlightbook never shows a 12 month expiration because a constituent piece is that you must be current by 61.57(a) as well, and that's 90-day limited. I've had pilots be confused because there are multiple paths to currency (61.57(b) and 61.57(e)) that yield different expiration dates, and they're expecting one that is different from what MyFlightbook reports.
All of the currencies above are experience based, so the "expiration" date moves with experience, but the principle here holds even for date-based currency, such as your medical certificate.
Technically, your medical doesn't expire, even though MyFlightbook reports an expiration date for it. Rather, you can think of the privileges it bestows as decaying over time. Just yesterday, I had a pilot tell me that MyFlightbook's computation was incorrect because he got a 2nd-class medical and those, he said, last for 24 months for someone over 40.
He's correct in one sense, that you cannot exercise privileges requiring a medical without seeing a doctor after 24 months. But I think he missed the larger point that nobody cares about the certificate per se. Pilots need to care about the privileges that the certificate allows you to exercise.
The duration of a medical is described in 61.23(d), in what I think may be the most obtuse possible way.
I would, instead, summarize that duration table this way, which is I hope far simpler and more clear than the FAA's formulation:
| Class of medical | 1st class privileges expire | 2nd class privileges expire | 3rd class privileges expire |
|---|---|---|---|
| 1st class | 6 calendar** months | 12 calendar months | 24 calendar months if you are over 40, otherwise 60 calendar months |
| 2nd class | N/A | ||
| 3rd class | N/A |
So the pilot above has a 2nd class medical that is good for 12 months for operations requiring a 2nd class medical, and its good for 24 months for operations requiring a 3rd class medical. In other words, it's not the certificate per se that has an expiration date, it's the privileges it confers - and there are multiple such privileges simultaneously!
MyFlightbook handles these multiple privileges automatically.
For example, I am over 40 years old. If I put in a 2nd class medical using November 2025 (it's March of 2026 right now), then I'll see this in my currency:
This is the 12-calendar month expiration that the pilot referred to as being in error.
But if I change the date of that 2nd-class medical to Nov of 2024 instead of 2025, the "expiration date" bifurcates:
Still a 2nd class certificate, but MyFlightbook is now reporting that the 2nd class privileges expired at the end of Nov 2025 (12 calendar months from the date of the exam), but that 2nd class certificate is still valid for operations that require only a 3rd class medical until Nov of 2026!
Hopefully this clarifies how "expiration dates" work in MyFlightbook.*61.57(a) requires both takeoffs and landings, but MyFlightbook ignores takeoffs for this computation because they are so rarely logged as a practical matter. Night currency is more strict about this - it ignores them if it finds none and warns you that you need to do them, but if even one night takeoff is logged anywhere in your logbook, they become required.
**Interestingly, while the FAA is usually really good about using the phrase "Calendar Month" when they mean calendar month, in the table of 61.23(d), they use the phrase "...at the end of the last day of the (Nth) month after the date of the examination on the medical certificate." This is functionally the same, just expressed in a more verbose manner.
